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Portion of the skull that contains the braincase and upper rostral regions



Part of the skull that includes the lower jaw



A "box" of bone protecting the brain

Associated elements:
- Auditory bullae
- Occipital condyles
- Processes and ridges associated with muscle attachment
- Foramina and canals for the passage of nerves and blood vessels



Group of bones that project anteriorly from the anterior edges of the orbit

- Upper jaw
- Bones surrounding the nasal passage
- Bones dividing nasal passage and oral cavity



Eye socket


Nasal Bones

Are long and slender
Form the roof of the nasal passage
Paired; meet at the midline
Are situated dorsally and form part of the rostrum


Frontal Bones

Posterior to the nasal bones, form the forehead
Extend down the side of the skull to form the inner wall of the orbit
- postorbital process
- temporal ridges/sagittal crest


Postorbital Process

Projection of the frontal bone that marks the posterior margin of the orbit


Parietal Bones

Paired, posterior to the frontal bones



Small unpaired bone located between the posterior edges of the parietals
Fused posteriorly with the occipital in Canis


Temporal ridges

Ridges on the frontal bones near the postorbital processes; serve as sites for muscle attachments
Continue posteriorly until they converge to form the sagittal crest


Sagittal crest

Crest running antero-posteriorly on the skull, serves as a site for muscle attachments


Occipital Bone

Single fused bone
Forms the posterior portion of the skull
- Foramen magnum
- Occipital condyles
- Auditory bullae
- Occipital crests
- Paraoccipital processes


Foramen magnum

Hole near the centre of the occipital through which the spinal cord passes
Flanked by the occipital condyles


Occipital condyles

Paired knobs which flank the foramen magnum on the occipital bone
Articulate with the atlas (first cervical vertebra)



Tooth-bearing bones at the anterior end of the rostrum
Contain two branches:
- Palatal branches meet along the midline and form the anterior portion of the hard palate
- Nasal branches project dorsally and posteriorly to form the sides of the nares



Anterior opening of the nasal passages



Posterior to the premaxillae
Form the major portions of the side of the rostrum
- Infraorbital canal/foramen


Infraorbital canal/foramen

Hole in each maxilla that terminates in the orbit
Serves as the passage for blood vessels and nerves to get to the snout
- When it's a large hole, elongated
- Small, non-elongated hole


Hard palate

Separates the buccal cavity from the nasal passagesConsists of the palatal branches of the premaxilla and maxilla as well as the palatines



Paired bones
Posterior to the maxillae on the ventral surface of the cranium



Unpaired bone that forms a septum between the two nasal passages



A.K.A. turbinate bones
Highly convoluted bones within the nasal passages



Paired bones posterior to the vomer



Unpaired bone posterior to the vomer, medial to the pterygoids and anterior to the basisphenoid


Temporal fossae

Large space between the zygomatic arches and the remainder of the cranium
Posterior to the orbit (may not be separated in all species)
Some of the muscles pass through this


Zygomatic arches

Conspicuous bony arches that form the ventral and lateral borders of the orbit
Short process on dorsal edge marks the posterior edge of the orbit



Anterior portion of the zygomatic arch
Articulates with the zygomatic process of the maxilla



Bones ventral to the parietals
Zygomatic process articulates with the posterior portion of the jugal to form the zygomatic arch


Postorbital bar

When the process on the zygomatic arch is continuous with the postorbital process on the frontal
Separates the orbit from the temporal fossa


Mandibular fossa

Articulation surface for the lower jaw
On the ventral side of the base of each zygomatic process of the squamosal



Bone inside each orbit at the anterior root of each zygomatic arch
Has a foramen which is for the passage of the lacrimal (tear) duct


Auditory bullae

Bulbous structures between the mandibular fossae and the occipital condyles
Not present in all mammals


External Auditory Meatus

Opening on the side of each auditory bulla
Tympanic membrane (eardrum) is stretched across it
Within each bulla is the middle ear chamber; contains three ossicles


Auditory ossicles

Bones in the middle ear chamber of the auditory bulla
- Incus
- Malleus
- Stapes



Paired bones that form the mandible
Firmly attached in carnivorans and fused in primates
Two major parts: body and ramus



Horizontal portion of each dentary that normally bears teeth



Vertically projecting portion of the dentary


Mandibular condyle

Portion of the mandible that articulates with the mandibular fossa of the cranium
Flanked dorsally by the coronoid process and ventrally by the angular process


Coronoid Process

Is dorsal to the mandibular condyle and extends to fit into the temporal fossa
Is a surface for muscle attachments


Angular Process

Ventral to the mandibular condyle
Protrudes posteriorly


Masseteric Fossa

Depression near the bases of the processes on the ramus
Can be deep in some mammals


Determination of maturity

- Heavily worn teeth indicate older adult, especially if teeth are missing
- Height of sagittal crest / length of postorbital processes increase with age
- Presence of deciduous teeth means immature
- Unerupted teeth means immature
- Degree of fusion of cranial sutures



Portion of a tooth that is exposed above the gumline



Portion of a tooth that fits into the alveolus



Portion of the jaw that contains the tooth sockets



Teeth with particularly high crowns



Teeth with especially low crowns



Points and bumps on the crown
Can be unicuspid, bicuspid, tricuspid, etc.



Bonelike material that makes up the major portion of each tooth



Hard material that covers the dentine of the crown



Bonelike material that covers the dentine of the root



Central, living portion of a growing tooth


Root canal

One or more openings in the base of a tooth that supply blood vessels and nerves to the pulp



When a tooth reaches a certain size and the root canals restrict, restricting blood flow and stopping growth



When the opening of the root canals never constrict and thus the teeth grow throughout the life of the mammal



Having only two sets of teeth: deciduous and permanent


Deciduous Teeth

A.K.A. milk teeth
Set of teeth that are present in immature mammals


Permanent Teeth

Set of teeth that are retained for the remainder of an individual's life



Only one set of teeth are grown and used throughout the animal's life
E.g. toothed cetaceans


Tooth replacement in animals that feed on harsh vegetation

Tooth replacement occurs as the teeth are worn away



When an individual has two or more morphologically different teeth in their jaw



When all teeth in the jaw have the same basic shape



Rooted in the premaxillary bone on the upper jaw
Usually unicuspid with a single root, generally chisel-shaped

There are never more than three incisors in each jaw quadrant in placental mammals
Marsupials may have up to five incisors in each half of the upper jaw and four in each half of the lower jaw



Most anterior teeth rooted in the maxilla
Never more than one per quadrant
Usually long, conspicuous and unicuspid with a single root



When there is a wide space between the anterior teeth and cheek teeth
Generally caused by the absence of some teeth



When an incisor and/or premolar appears to be a canine
Canine is generally incisiform or molariform in this case



When the canine resembles an incisor
Usually occurs when the first premolar is caniniform



The teeth just posterior to the canines
Have deciduous predecessors in the milk dentition
- In placental mammals with four premolars, the first does not have a deciduous precursor
- This also occurs in some other mammals with less than four premolars



Situation posteriorly to the premolars
Never have deciduous predecessors
Usually larger than premolars and have more cusps


Cheek Teeth

A.K.A. postcanine teeth, molariform teeth
The premolars and molars
Frequently called this because it can be difficult to distinguish between premolars and molars
Structure of the cheek teeth is one of the most important criteria in the classification of mammals and inferring their diet


Marsupial Teeth

Incisors: max. 5 upper, 4 lower
Canine: 1
Premolars: max. 3
Molars: max. 4


Placental Teeth

Incisors: max. 3
Canine: 1
Premolars: max. 4
Molars: max. 3



Chewing, or processing of the food



Simple, triangle-shaped cheek teeth with three main cusps

Found in early marsupials and placental mammals of the Cretaceous; has been modified in various modern lineages and is found in many insect-eating mammals

Crests between cusps can form a V-shape or W-shape



Teeth that have four main cusps; mostly square crown; frequently brachydont
Found in many omnivorous mammals



Teeth with four major cusps and a mostly quare crown



Teeth with very high crowns; this is because plants are abrasive and quickly erode teeth

Found in herbivores



Cusps fuse to form elongated ridges known as lophs, creating elongated abrasive surfaces for the grinding of plant material



Ridges form in the teeth due to the elongation of a single cusp per ridge
Ridges are always crescent-shaped and longitudinally oriented



Teeth that combine aspects of both selenodont and lophodont teeth
Found in mammals such as horses


Prismatic Teeth

A tooth type that is characterized by many infoldings along the margins of the teeth



Modification for a carnivorous diet where the cheek teeth are reduced to only have two major cusps
Scissor action is simulated by the upper and lower teeth shearing against one another, tears off flesh


Carnassial Teeth

Found only in the order Carnivora
Two teeth on each side of the jaw that do the majority of shearing; the largest and most conspicuous cheek teeth

In Adults:
- Fourth upper premolar
- First lower molar
In Juveniles:
- Third upper premolar
- Fourth lower premolar


Insectivorous Tooth Specializations

Three cusps of teeth are elongated into sharp, crescent-shaped ridges
Useful for cutting and crushing the hard, chitinous exoskeletons of insects


Omnivorous Tooth Specializations

Bunodont cheek teeth


Herbivorous Tooth Specializations

Lophodont, selenodont, or selenolophodont teeth


Rodent Tooth Specializations

- simplification of occlusal pattern
- fusion of cusps
- prismatic teeth


Carnivorous Tooth Specializations

Secodont teeth
Carnassials in Carnivora


Piscivorous Tooth Specializations

Cheek teeth are reduced to a series of sharp unicuspid teeth



When an animal feeds on large quantities of small insects such as ants and termites
E.g. echidnas, anteaters, pangolins



When an organism lacks teeth entirely



Plates in the mouths of the baleen whales which filter krill from the ocean water


Dental Formula

Shorthand method used to indicate the numbers of each tooth in a particular mammal

E.g. (Human):
- 2/2 1/1 2/2 3/3


Ancestral Dental Formulae

The numbers of teeth found in mammalian ancestors
Reduction from this number is common but an increase is very rare


Ancestral Marsupial Dental Formula

I5/4 C1/1 P3/3 M4/4
Total = 50


Ancestral Placental Dental Formula

I3/3 C1/1 P4/4 M3/3Total = 44


Grouped Dental Formula

When the premolars and molars are impossible to distinguish and there are not seven cheek teeth in each quadrant, the premolars and molars are grouped together in the dental formula

E.g. I3/2 C1/1 P+M5/5; Total 34


Axial Skeleton

Portion of the skeleton consisting of the midline of the body proper
- Skull
- Vertebrae
- Bones of the thoracic cavity; rib cage


Dermal Skeleton

Generally rudimentary or absent in mammals
Big exception: armadillos


Appendicular Skeleton

Skeleton of the paired appendages as well as the pectoral and pelvic girdles


Cervical Vertebrae

First set of vertebrae immediately posterior to the skull
Seven are present in virtually all mammals- Exceptions: sloths and sirenians



First cervical vertebra



Second cervical vertabra


Hyoid Bones

Horseshoe-shaped bones in the neck; articulated to other bones by muscles and ligaments
Aid in tongue movement and swallowing


Thoracic Vertebrae

Vertebrae that articulate with the ribs to help form the thoracic cavity



Have a head that articulates with the body of a thoracic vertebra as well as another articulation point that touches the transverse process of an adjacent vertebra
Distal ends of anterior ones articulate with the sternum, more posterior ones connect indirectly via cartilage
- May be a final (few) pair(s) of unattached free ribs



The series of bony segments that provide the midventral completion of the thoracic cavity


Costal Ribs

Ribs that connect with one another and ultimately the sternum indirectly via cartilage


Free Ribs

The most posterior ribs that do not connect with the sternum at all, either indirectly or directly


Lumbar Vertebrae

Form the lower back and are the arch that supports the muscular-walled abdominal cavity


Sacral Vertebrae

Vertebrae that articulate with the pelvic girdle
Are often somewhat fused together and are sometimes fused to the pelvic bones as well


Caudal Vertebrae

Vertebrae that make up the tail
Some are usually present, but may be reduced to a few small, fused rudiments in "tailless" species (i.e. humans)



A.K.A. os penis

Bone located within the penis
Structure varies greatly between groups; found in all carnivores, most primates/rodents/bats, some insectivores
Much smaller os clitoris is found in the glans clitoris of females of species whose males have a baculum


Pectoral limb




Shoulder blade
Large, plate-like bone embedded in muscles dorsal and/or lateral to the ribs
Has no direct articulation with any bones in the axial skeleton



Extends from the glenoid fossa (shoulder socket in the scapula) to the sternum
Provides the base for the anterior limb
Reduced or absent in mammals adapted to run on hard ground


Scapular Spine

Ridge of bone extending vertically for much of the length of the scapula
Provides additional surface area for muscle attachment



Normally the third main bone in the pectoral girdle; rudimentary and fused with the scapula in marsupials and placental mammals
Well-developed in monotremes



Proximal element of the pectoral limb
Large head articulates with the glenoid fossa in a ball-and-socket joint, allowing great mobility



Articulates proximally with the humerus in a hinge joint (movement occurs in only one plane)



Articulates proximally with the humerus in a way that allows it to rotate around the ulna
More medial of the radius and ulna, aligns with the first digit


Olecranon Process

Extends proximally beyond the humerus
Short arm lever for attachment of muscles that extend the forearm
Prevents the forelimb from being completely straightened in most mammals



Hand or forefoot



Small bones located posteriorly on the manus
Allow for sturdy flexibility in the wrist



Primitive condition for mammals
Have five digits on the hand/foot
Reduction is common, addition is not



Elongate bones, one for each digit
Enclosed within the forefoot



Singular: phalanx
Extend from the distal end of each metacarpal to form each digit
First digit has two phalanges, 2-5 have three



Most medial digit on the forefoot
Has only two phalanges


Pelvic Limb



Pelvic Girdle

Hip Girdle, single structure formed by the fusion of three pairs of bones
- Ilia (s. ilium) lie dorsally and articulate with the sacral vertebrae
- Ischia (s. ischium) direct posteriorly and form the bony part of the rump
- Pubic bones are paired, project anteriorly and ventrally; joined on distal ends
Ring through which the digestive, urinary, reproductive tracts all exit the body


Pubic Symphasis

The junction between the two pubic bones
Somewhat elastic in the females of some species to allow for the passage of a large fetus during birth



Large socket that receives the head of the femur
Is at the point where the three pelvic bone meet



Proximal element of the pelvic limb



More medial of the distal leg bones
Larger than the fibula in most mammals



Forms the distal end of the leg along with the tibia
Often reduced in mammals, and is generally smaller than the tibia



Develops within a tendon on the anterior side of the knee joint between the femur and tibia and fibula


Tarsal Bones

A.K.A. ankle bones
Correspond to the carpals of the forelimb



Largest of the tarsals
- "heel bone"

Extends posteriorly from the joint with the tibia
Serves as the attachment site for the achilles tendon; similar to that of the olecranon process



Large tarsal bone adjacent and medial to the calcaneum



Elongate bones that extend from the tarsals
Correspond to the metacarpals on the forelimb



Most medial digit on the foot
Consists of two phalanges



Hind foot, including the tarsals, metatarsals and phalanges



Most primitive of the protective keratinizations found on the digits

Encases the last phalanx of the digit
- Unguis is better developed and harder, curves longitudinally and transversely
- Subunguis is enclosed between the lower edges of the unguis

Can aid in increasing traction and stability, digging, climbing, catching prey



The dorsal, scale-like plate on a claw/nail



Ventral plate on a claw/nail



Modified claw that covers only the dorsal surface of the end of a digit
- Unguis is broad and flattened
- Subunguis is reduced to a small remnant that lies under the tip of the nail

Provide less protection than claws but allow for greater precision in manipulation of stuff



Unguis curves almost completely around the end of the digit and encloses the subunguis within

Pad lies just behind the hoof and is called the frog

In ungulates, only the hoofs are in contact with the ground, providing good traction and preventing wear on the digits


Ambulatory Locomotion


Generalized mammalian limb structure is well suited for this
- Unmodified metacarpals and metatarsals
- Pectoral and pelvic limbs about equal in length
- Joints allow movement of limbs in several planes
- Plantigrade



Feet lie flat on the substrate
All phalanges, metapodials and carpals/tarsals lie on the ground


Cursorial Locomotion


- Digitigrade or unguligrade
- Increase in limb length increases stride length



Metacarpal and metatarsal portions of the feet never touch the substrate during locomotion

Frequently exhibit reduction in the number of toes and elongation of the metacarpals and metatarsals



Phalanges are elevated so only the hooves are in contact with the substrate
Proximal portions of the limbs are shortened and very muscular
Radius usually fused with the ulna and fibula with tibia
Radius, ulna, tibia, fibula, metacarpals, metatarsals, phalanges are usually greatly elongated
Generally greatly reduced number of digits


Saltatorial Locomotion

Move using a series of leaps with the hindlimbs being the main propulsive force
Can be quadrupedal



Leap in which all four feet are involved



Form of saltatorial movement where the organism moves bipedally; forefeet are not used
- Have greatly elongated and muscular hind limbs, reduced forelimbs
- Very long pes; tail is also usually long and tufted at the tip, functions as a counterbalance
- Useful for quick movement over soft substrates, frequent in desert mammals



Essentially columnar limb
- Bottom of the foot rests on a thick cushioning pad
- Seen in heavy mammals (i.e. elephants)

Can be considered semi-digitigrade - arguments could be made for digitigrade or plantigrade


Semifossorial Locomotion

Mammals that burrow into the ground but also spend a lot of time above ground

Constantly alert, so eyes are usually placed high on the head


Fossorial Locomotion

Live underground and only rarely come to the surface
- Body is compact
- Tail is reduced or rudimentary
- Neck is very short
- Pinnae are tiny/absent
- Eyes are usually vestigial
- Pectoral limbs and girdles are very robust


Semiaquatic Locomotion

Animals that spend a lot of time swimming, but not all the time

- Webbed feet
- Some have a fringe of stout hair along the edge of the foot (increases surface area)
- Generally fusiform body
- Frequently flattened tail
- Valvular ears and nostrils, eyes protected by membrane
- Pinnae and other projections reduced


Pinniped Locomotion

Spend most of their lives in the water but come ashore to give birth
- Limbs are modified into flippers
- Shortened neck and small forelimbs in phocid seals
- Long neck and large forelimbs in otariids


Aquatic Locomotion

Cetaceans and sirenians, do not regularly come to land
- Body very fusiform
- Short, thick neck
- Even taper from the trunk to the tip of the tail
- Forelimbs modified to flippers
- Hindlimbs are absent externally
- Tail tip laterally expanded and dorsoventrally flattened to form paddle-shaped structure or fluke
- Swim by undulating the posterior part of the body in a vertical plane; pectoral appendages used primarily for maneuvering; dorsal fin aids in stabilization



Tail tip in dugongs and cetaceans
- Laterally expanded and dorsoventrally flattened
- Composed of fibrous connective tissue without bony support


Dorsal Fin

Fin on the dorsal side of the body
Present in many cetaceans


Prehensile Tail

Tail that can be used as another limb, strong enough to support the animal's body weight


Scansorial Locomotion

Animals that run through the trees (e.g. tree squirrels)
Little obvious modifications for arboreal life
- Sharp, strong claws (scampering up vertical surfaces)
- Long, fluffy tails for balance


Arboreal Locomotion

Animals that cling to branches by prehensile and opposable digits and/or prehensile tails


Brachiating Locomotion

Swing through the trees using hands
- Kind of an inverted bipedal walk with the hands
- Olecranon process is small and allows the arm to extend perfectly straight
- Very long fingers


Sloth Locomotion

Found in sloths and colugos
Inverted quadrupedal walk
- Animal hangs suspended from all four limbs
- Hang from strong, curved claws


Gliding Locomotion

Have a patagium between the forelimbs and hindlimbs
- Allow them to glide between trees
- Maneuver by lifting and lowering the limbs and tail in midair



Order within Mammalia
- Reptilian features inc. sprawled limbs and egg-laying
- Teeth absent in all adults; may form tooth buds in juvenile platypuses but these disappear soon after birth
- Instead, platypuses have horny plates that are continually growing
- Lacrimal and frontal bones absent
- Jugals reduced or absent, but zygomatic processes of maxilla and squamosal meet to form complete zygomatic arch
- Jaws covered with rubbery, hairless skin
- Large claws on each digit
- Large, hollow spur on the ankle of males (and some female echidnas); venom-secreting gland at base in platypuses
- No nipples on the mammary glands
- Penis bifurcates at the tip and is attached to the ventral wall of the cloaca
- Females have 10 X chromosomes, males have 5 X & 5 Y
- Auditory bullae are absent
- Prominent epipubic bones


Epipubic Bones

Paired bones that project anteriorly from the pelvic girdle into the abdominal body


Identification of Echidnas

Skulls may resemble those of small anteaters or pangolins (which are also toothless and cone shaped)
- Echidnas have a more elevated braincase
- Premaxillae of Tachyglossus are bent slightly upward
- Anteaters have well-developed lacrimal bones (absent in echidnas and pangolins)
- Pangolin skulls tend to be more robust and lack an angular process



Infraclass, contains Superorders:
- Ameridelphia
- Australidelphia
(Total of 7 Orders)

- Marsupium in 2/3 of living species
- Always more upper than lower incisors (except wombats, Vombatidae - Diprodontia)
- Primitive formula is 3 premolars and 4 molars (reverse of placentals)
- Total number of teeth often exceeds 44
- Diprotodont teeth in two orders
- Canines and first premolars frequently incisiform
- Angular process inflected (projects medially, exception is koala)
- Jugal contributes to mandibular fossa in all marsupials except genus Tarsipes
- Most are plantigrade, some digitigrade
- Hallux lacks a claw in all marsupials
- Simple yolk sac placenta in most, chorioallantoic in Peramelemorphia
- Epipubic bones present in males and females, vestigeal in marsupial moles and Tasmanian wolf
- Two separate uteri with two vaginal canals (temp. median birth canal during childbirth)
- Penis often bifurcate, no baculum; scrotum anterior to penis
- Separate urogenital and digestive openings in most species (exception is Microbiotheria)



Condition where the lower jaw is shortened and the first pair of lower incisors are very enlarged and elongated



Non-diprotodont, or normal tooth condition



Condition where two toes are fused so the skeletal elements of both are encased within one skin sheath
- Two claws will project from the end of this digit



Condition with no fused digits, opposite of syndactylous



Superorder within Metatheria, contains:
- Didelphimorphia
- Paucituberculata

Marsupials from the New World



Superorder within Metatheria, contains:
- Dasyuromorphia
- Notoryctrmorphia
- Peramelemorphia
- Diprotodontia
- Microbiotheria



Order within Ameridelphia
Neotropical region, except Didelphis virginiana, which ranges into the Nearctic

- Most probably omnivorous
- Terrestrial and arboreal, one semiaquatic, some semifossorial
- Marsupium more absent than present


Identification of Didelphimorphia

- Incisors are 5/4, small, peg-like
- Polyprotodont
- Canines are well-developed
- Pentadactyl and no syndactylous digits
- Well developed hallux is clawless and more or less opposable
- Tail prehensile to semi-prehensile
- Frequently have a naked, rat-like tail

May be confused with Microbiotheria or Peramelemorphia (both have five upper incisors)
- Microbiotheria has inflated auditory bullae
- Peramelemorphia has three lower incisors


Didelphis virginiana

- Long-haired, scruffy; naked nose and ears
- Rat-like tail is furred at base, then black and naked, then has long white tip
- Five toes on each foot, opposable hallux
- Incisors 5/4

Similar species
- Norway rat is much smaller and has shorter fur, with no fur on base of tail

- Nocturnal, though sometimes active by day in winter
- Climbs well, uses prehensile tail for balance
- May "play dead" if provoked
- Omnivorous and will eat almost anything
- Solitary
- Seminomadic; dens in hollow logs, rocks, burrows made by other animals
- Female gives birth to 8-16 2g young that attach to one of 13 nipples for 2 months; 3rd month on mom's back
- May have 2-3 litters per year

- Oldfields, forests, agricultural areas, roadsides, suburbs, and urban regions

- Common to abundant
- Frequently roadkill
- Sometimes killed for meat in southern US

- Native from Central America all the way to Southern Ontario
- Introduced widely along the west coast



Order within Ameridelphia
Caenolestids - flaplips/shrew-opossums
Neotropical region

- Small and shrew-like
- Feed on invertebrates, plants, fungi and seeds


Identification of Paucituberculata

- Diprotodont
- Incisors usually 4/3
- External membranous flap on both sides of the upper and lower lips
- Marsupium always absent
- Tail long and haired to tip
- Limbs subequal
- Didactylous
- Can be distinguished from Diprodontia because they have 4 upper incisors
- Can be distinguished from mice and shrews due to clawless hallux and flaps on lips



Order within Australidelphia
Carnivorous/insectivorous marsupials - Tasmanian wolf, Tasmanian devil, numbat
Australian region

- Mostly terrestrial, a few arboreal/semifossorial


Identification of Dasyuromorphia

- Polyprotodont
- Incisors 4/3
- Canines well-developed in most
- Didactylous toes
- Hallux clawless if present
- Marsupium, if present, opens to the rear
- Non-prehensile tail
- Can be distinguished from similar eutherians because of 4 upper incisors, inflected angular process, and clawless hallux



Order within Australidelphia
Marsupial moles
Australian region

- Fully fossorial
- Live in sandy deserts
- Feed on insects


Identification of Notoryctemorphia

- Dental formula I 3-4/3 : C 1/1 : P 2/2-3 : M 4/4 (T: 40-44)
- Skull conical in shape
- Skin has horny rostral shield
- Claws are very enlarged on third and fourth digits to form spades
- Pinnae and externally visible eyes absent
- Fur silky, pale, iridescent
- Tail short, naked, conical
- Marsupium present
- Vestigial epipubic bones
- Inflected angular process distinguished from eutherians
- Skin unique in having less than 5 digits on forefeet and horny rostral shield (golden moles have small rostral pad but no external tail)



Order within Australidelphia
Bandicoots and bilbies
Australian region

- Terrestrial
- Primarily insectivorous
- Vaguely similar to rabbits in size and appearance


Identification of Peramelemorphia

- Polyprotodont
- Dental formula I 4-5/3 : C 1/1 : P 3/3 : M 4/4 (T: 46-48)
- Incisors have flattened crowns
- Wide space between canines and last incisor/first premolar
- Syndactylous digits on hind feet
- Elongate rostrum
- Skull conical in shape
- Hindlimbs larger than forelimbs
- Reduced number of digits on pes and manus
- Clavicle rudimentary or absent
- Marsupium always present, opens to rear
- Chorioallantoic placenta, but lacks villi seen in eutherians
- Can be distinguished from eutherians by number of upper incisors and inflected angular process
- Skin can be distinguished from others because of syndactylous digits



Order within Australidelphia
Kangaroos, wallabies, koalas, possums, wombats, etc.
Australian region

- Vary considerably in size
- Occupy diverse habitats
- Terrestrial, semifossorial, or arboreal


Identification of Diprotodontia

- Diprotodont
- Incisors can be 3/2-3; 3/1; 2/1 or 1/1
- Second and third lower incisors minute when present
- Syndactylous second and third digits of hind foot
- Marsupium always present, opens anteriorly or posteriorly
- Can be distinguished from paucituberculatans (who are also diprotodont) by having less than four upper incisors
- Inflected angular process means marsupials



Order within Australidelphia
Monito del monte (only extant species)
Neotropical region

- Opossum-like in appearance
- Scansorial or semiarboreal
- Lives in dense, humid forest
- Insectivorous or faunivorous


Identification of Micriobiotheria

- Polyprotodont
- Incisors 5/4
- Large, inflated auditory bullae
- Didactylous toes
- Opposable hallux
- Marsupium present
- Tail prehensile, equal in length to body, furred all over except ventral strip
- Can be distinguished from opossum skulls due to large auditory bullae
- Can be distinguished from opossum skins due to long furred tail; naked strip distinguishes from small eutherians
- Can be distinguished from diprotodontians due to didactylous digits
- Can be distinguished from rodents because of opossable hallux with no claw



Superorder within Eutheria, contains Orders:
- Cingulata
- Pilosa
Sloths, armadillos, anteaters
Neotropical region except one species ranging into southcentral Nearctic

- Extra (xenarthrous) articular surface between vertebrae, esp. in lumbar region
- Incisors are generally reduced or absent
- Deciduous teeth are absent
- Cheek teeth (when present) lack enamel
- Cheek teeth (when present) have only single, open root
- Limbs specialized for digging or climbing



Order within Xenarthra
Neotropical region and one species in Nearctic

- Terrestrial to fossorial
- Possess a carapace over much of the body, formed by plates of dermal bone that are covered in small, overlapping keratinous scutes
- Armour ranges in protection from full coverage when rolled into a ball to a thin stretch
- Most are only sparsely haired, but some are very hairy
- Most feed exclusively or primarily on insects


Identification of Cingulata

- Cheek teeth are cylindrical, homodont, and ever-growing
- No incisors or canines
- Deciduous teeth only in genus Dasypus
- Some species have more than 7 cheek teeth



Order within Xenarthra, contains Suborders:
- Vermilingua
- Phyllophaga
Anteaters and Sloths
Neotropical region



Suborder within Pilosa
Anteaters and tamanduas
Neotropical region

- Feed primarily on ants and termites
- Terrestrial and arboreal
- Tamanduas and pygmy/two-toed anteaters have prehensile tails


Identification of Vermilingua

- Edentulate
- Rostrum long and slender with very small mouth opening
- Long, vermiform (worm-like) tongue
- Large foreclaws used to tear open ant/termite nests
- Can be distinguished from echidnas by lack of elevated braincase, lacrimal bones,
- Can be distinguished from pangolins by being less robust, presence of angular process



No teeth



Suborder within Pilosa
Neotropical region

- Arboreal
- Long limbs and syndactylous toes
- Large, curved claws for hanging from tree branches
- Have coarse hair that houses algae
- Vegetarian


Identification of Phyllophaga

- Incisors and canines absent
- Cheek teeth cylindrical, ever-growing and basically homodont
- Rudimentary tail
- Can have cervical vertebrae numbering more or less than 7
- Two-toed sloths have two claws on forefeet and three on hindfeet; caniniform anterior tooth
- Three-toed sloths have three claws on all four feet; all teeth essentially homodont



Superorder within Eutheria, contains Orders:
- Afrosoricida
- Macroscelidea
- Tubulidentata
- Proboscidea
- Sirenia
- Hyracoidea
Includes elephants, sirenians, hyraxes, golden moles, aardvarks, etc.
Ethiopian region

No morphological support but molecular data strongly supports this as a clade



Order within Afrotheria, contains Suborders:
- Tenrecomorpha
- Chrysochloridea
Tenrecs, otter shrews, golden moles
Ethiopian region



Suborder within Afrosoricida
Tenrecs and otter shrews
Ethiopian region
- Insectivorous- Vary greatly in form and habits
- Shrew- to rabbit-sized
- Can resemble shrews, moles, desmans, or hedgehogs
- Otter shrews are semiquatic


Identification of Tenrecomorpha

- First upper premolar is never present
- Molars are 3/3; 4/3, or 2/2
- Upper molars have crowns that are triangular in occlusal view
- Rostrum frequently long and slender
- No auditory bullae or zygomatic arches
- No jugal
- Eyes usually small
- Obvious pinnae
- Can be distinguished from shrews because first upper incisor does not protrude, has no accessory cusp, and is never pigmented



Suborder within Afrosoricida
Golden moles
Ethiopian region

- Diet is mainly invertebrates (termites)
- Live in forests, savannahs and sand dunes
- Closely resemble true moles with the fossorial adaptations of marsupial moles


Identification of Chrysochloridea

- Dental formula I 3/3 : C 1/1 : P 3/3 : M 3/3 (T: 40)
- First upper incisor is enlarged
- Crests between cusps of upper molars are V-shaped in occlusal view
- Conical or wedge-shaped skull
- Leathery pad at tip of snout
- Auditory bullae present
- No jugal bone, zygomatic arch made by elongate processes
- Eyes are vestigial and covered in skin and fur
- Can be distinguished from true moles by V-shaped crests between cusps, weak zygomatic arch and four digits on forefeet



Order within Afrotheria
Elephant shrews/sengis
Ethiopian and Palearctic regions

- Diurnal insectivores
- Long, slender and highly mobile snout
- Snout has many basal vibrissae
- Large eyes and ears
- Hind limbs slender and elongated
- When alarmed, hop on digitigrade hind feet
- Soft fur
- Long slender tail covered with scales


Identification of Macroscelidea

- Hind limbs much longer than forelimbs
- Distal portions of limbs longer than proximal portions
- Fused tibia and fibula
- Dental formula I 1-3/3 : C 1/1 : P 4/4 : M 2/2-3 (T: 36-42)
- Fourth premolar is molariform
- Molars are usually four-cusped
- Upper molars with crests between cusps are V-shaped
- Large perforations in palate
- Complete zygomatic arch
- No complete postorbital bar
- Well-developed auditory bullae
- Can be distinguished from marsupials due to lack of inflected angular process
- Can be distinguished from Scandentia and Primates due to lack of postorbital bar
- Can be distinguished from Chiroptera and Carnivora due to poorly developed canines



Order within Afrotheria
Aardvark - Orycteropus afer
Ethiopian region

- Semifossorial
- Somewhat pig-like in appearance
- Digits terminate in structures intermediate between claws and hooves - used to burrow and tear open termite mounds
- Long, extensible tongue


Identification of Tubulidentata

- Skull is elongated and conical
- Incisors and canines are absent
- Cheek teeth usually number 5/5
- Cheek teeth are ever-growing, oval/B-shaped, flat-topped, and clumnar
- Cheek teeth lack enamel and are composed of hexagonal prisms of dentine surrounding tubular pulp cavities
- Limbs are digitigrade
- Four digits on manus and five digits on pes
- Snout is elongated and pig-like
- Ears are much longer than wide
- Tail is long and tapers gradually
- Thick skin with sparse bristle-like hairs



Order within Afrotheria
Ethiopian and Oriental regions

- Long, prehensile trunk
- Browsing and herbivorous


Identification of Proboscidea

- Incisors are 1/0 and are long, ever-growing tusks of solid dentine; frequently absent in female Asiatic elephants
- Canines absent
- Cheek teeth are hypsodont and lophodont
- Cheek teeth are replaced from the back of the jaw as worn teeth are shed from the front of each tooth row
- Limbs are graviportal and have five digits terminating in a hoof-like structure
- Upper lip and nose are fused to form the trunk, with nostrils at distal end
- Skin is thick and covered in spare, bristle-like hairs



Order within Afrotheria
Manatees and dugongs
Nearctic, Neotropical, Oriental, Australian and Ethiopian regions

- Fully aquatic
- Lack external hindlimbs
- Forelimbs modified to become flippers
- Short but flexible neck
- Mammae are pectoral
- Feed on aquatic vegetation
- Hunted for meat, hides and oil
- Tropical and subtropical


Identification of Sirenia

- External nares high on the skull, posterior to anterior margins of the orbits
- Nasal bones rudimentary or absent
- Incisors absent in manatee, 1/0 in dugong
- Canines absent
- Cheek teeth are either replaced by more teeth as in elephants or replaced by horny plates
- Vestigial pelvic limbs, not visible externally
- Pectoral limbs paddle-like, five digits indistinguishable externally
- Tail has horizontally flattened fin (cleft in dugongs)
- Manatees have only six cervical vertebrae
- Ribs are massive
- Horizontal stability enhanced by elongated lungs and horizontal diaphragm
- Eyes are small
- Pinnae absent
- Lips large and highly mobile
- Stiff vibrissae present on upper lip, otherwise body is nearly naked



Order within Afrotheria
Ethiopian region mostly, one genus in Palearctic

- Rabbit-sized, look much like rodents
- Herbivorous
- Unique foot structure grants them a firm grip on rocks and trees in which they live
- Terrestrial species live in colonies


Indentification of Hyracoidea

- Adult dental formula I 1/2 : C 0/0 : P4/4 : M 3/3 (T: 34)
- Long, rootless upper incisors are triangular in cross-section and pointed
- Lower incisors are chisel-shaped and usually tricuspid
- Cheek teeth somewhat lophodont
- Wide diastema between anterior and cheek teeth
- Well-developed postorbital process usually forms postorbital bar
- Well-developed interparietal
- Large jugals contribute to mandibular fossa
- Plantigrade
- All four digits on manus are syndactylous except for the terminal phalanges
- Pes has three digits
- Flat, hoof-like nails except for second pedal digit, with grooming nail (claw-like)
- Soles of feet have soft, elestic pads kept moist by numerous glands
- Very short tail
- Can be distinguished from rodents by tringular cross section of upper incisors and presence of two lower incisors



Superorder within Eutheria, contains groups:
- Euarchonta
- Glires



Group within Euarchontoglires, contains orders:
- Dermoptera
- Scandentia
- Primates



Group within Euarchontoglires, contains orders:
- Lagomorpha
- Rodentia



Order within Euarchonta
Colugos/"flying lemurs"
Oriental and Australian regions

- Have an extensive patagium that allows them to glide
- Herbivores
- Move similarly to sloths when moving within a tree
- Crepuscular/nocturnal


Identification of Dermoptera

- Dental formula I 2/3 : C 1/1 : P 2/2 : M 3/3
- First upper incisors small, widely separated
- Second upper incisors caniniform
- Pectinate mandibular incisors 1+2, with each "tooth" a cusp
- Third lower incisor has 5-6 cusps
- Canine incisiform
- Brachyodont cheek teeth
- Skull broad and dorsoventrally flattened
- Furred patagia extend from neck to phalanges on manus, phalanges on pes and tail
- Only patagia to extend all around


Pectinate Teeth

Comblike teeth, have long slender cusps resembling the teeth of a comb



Order within Euarchonta
Tree Shrews
Oriental region
- Arboreal, semiarboreal, terrestrial
- Diurnal save for one species
- Omnivorous
- Large eyes
- Short facial vibrissae
- Low, rounded pinnae


Identification of Scandentia

- Dental formula I 2/3 : C 1/1 : P 3/3 : M 3/3
- Upper incisors large, sometimes caniniform
- Canine small and resembled ant. premolars
- Palate lacks large perforations
- Postorbital bar present
- Zygomatic arch complete & perforated w/ prominent hole
- Much more pointed face and shorter vibrissae than squirrels



Order within Euarchonta
Primates (duh)
Include suborders:
- Strepsirrhini
- Haplorhini



Suborder within Primates
Lemurs, lorises, galagos, etc.
Ethopian and Oriental regions
- Mostly nocturnal



Suborder within Primates
Tarsiers, New World, Old World
- Mostly diurnal, save tarsier and owl monkey


Identification of Primates

- Most have five digits, with pollex reduced or absent in some
- Plantigrade
- Prehensile digits with opposable pollex/hallux in most
- Nail always present on pollex, most have nails (some claws) on other digits
- Elongated calcaneum
- Orbits face anteriorly
- Narrow interorbital space
- Enlarged orbital cavity
- Stereoscopic vision for precise depth perception
- Postorbital bar or postorbital plate always present
- Bunodont and brachyodont cheek teeth
- Incisors do not exceed 2/2, premolars do not exceed 3/3


Identification of Strepsirrhini

- Lower incisors form a tooth comb, used in grooming (may be secondarily modified)
- Rhinarium naked and moist
- Rhinarium connected to mouth
- Nostrils lateral slits shaped like commas
- Claw on second toe for grooming
- Bicornate uterus


Identification of Haplorhini

- Rhinarium dry, separate from mouth
- Nostrils are oval in shape, face outward in platyrrhines and downward in catarrhines
- Postorbital plate in all but tarsiers
- Fun fact: cannot produce vitamin C
- Uterus has single chamber



Group within Laurasiatheria, contains orders:
- Erinaceomorpha
- Soricomorpha
Hedgehogs, shrews, moles, etc.
- May be that this is actually the order name, with just other families in it



Order within Eulipotyphla
Hedgehogs & gymnures
Ethiopian, Palearctic, Oriental regions

- Omnivorous
- Some hibernate
- Hair modified into spines in hedgehogs


Identification of Erinaceomorpha

- Dental formula I 2-3/2-3 : C 1/1 : P 3-4/2-4 : M 3/3
- Enlarged first upper incisors, also first lower in some species
- Bunodont upper molars
- Moderately large eyes and pinnae
- Snout usually long
- Complete zygomatic arches
- Plantigrade, five digits (except one genus)
- Can be distinguished from tenrecs (hedgehogs) by complete zygomatic arch, absence from Madagascar



Order within Eulipotyphla
Shrews, moles, desmans, solenodons
Nearctic, Palearctic, Ethiopian, Neotropical regions


Identification of Soricidae

Nearctic, Palearctic, Ethopian
- First incisor is enlarged and falciform
- Remaining teeth are small and peg-like
- Teeth may be pigmented
- Milk teeth shed before birth
- Long, narrow skull
- Zygomatic arch absent
- Auditory bullae absent
- Postorbital process absent
- Double articulation on mandibular condyle due to two processes



Bicuspid with forward projecting main cusp and small secondary cusp behind


Identification of Talpidae

Palearctic, Nearctic
- Body fusiform
- Eyes tiny and sometimes covered by skin
- Legs short and powerful
- Forelimbs rotated so palms face posteriorly
- Forelimb claws robust
- Pinnae absent
- Fur velvety in moles to allow for easy movement in the burrow
- Skull is long and flattened, with a narrow rostrum
- Complete zygomatic arches
- Auditory bullae present
- Snout snorkel-like in desmans
- Teeth never pigmented


Identification of Solenodons

- Snout long and flexible
- Feet large and clawed
- Tail long, nearly naked
- Zygomatic arch incomplete
- Auditory bulla absent
- Os proboscidis bone supports tip of rostrum
- Molar cusps are V-shaped
- Second lower incisor has deep groove for transfer of toxic saliva



Order within Glires
Rabbits, hares, pikas
Nearctic, Palearctic, Neotropical, Ethiopian, Oriental regions

- Tails are short to absent
- Hind feet are always at least somewhat larger than forefeet
- Rabbits have altrical young
- Hares have precocial young
- Almost completely herbivorous
- Cacophagy in most species, allows them to assimilate more plant nutrients and B vitamins



Young are born, naked, blind and are helpless



Young are born furred, sighted and capable of moving around on their own


Identification of Lagomorpha

- Dental formula I 2/1 : C 0/0 : P 3/2 : M 2-3/3
- First incisors large and "rodent-like"
- Second upper incisors small, peg-like, located directly behind first incisors
- Incisors rootless
- Long diastema between incisors and cheek teeth
- Cheek teeth hypsodont, rootless
- Cutting edge of upper anterior incisor straight in leporids and V-shaped in pikas
- Maxilla perforated on the side by either single large opening (pikas) or numerous small openings (rabbits/hares)
- Forefeet digitigrade
- Hind feet plantigrade
- Can be distinguished from rodents by second upper incisor, which is absent in all rodents



Order within Laurasiatheria
Nearctic, Neotropical, Palearctic, Ethiopian, Oriental, Australian regions (all of them)
Two kinds: pteropodids and non-pteropodids

- "hand-winged ones"
- Second largest mammalian order
- Mostly insectivorous, but some are frugivorous, nectivorous, piscivorous, sanguinivorous
- Some (but not all) use echolocation to navigate environment and catch prey
- Mostly nocturnal



Old World fruit bats and flying foxes
- Do not echolocate
- Fox-like faces
- Large body size
- Mostly fruit eaters, some nectar and pollen eaters
- Flight slow and maneuverable



Remaining 18 families of bats that use echolocation
- Usually small
- Reduced eyes
- Specialized nose pads/lower lips
- Ears have a tragus
- Wings are more derived than pteropodids, varies according to foraging patterns



Use of sound to investigate environment and find prey
- Pulse sounds produced by the larynx (tongue-clicks in only two echolocating pteropodids)
- Pulse sounds emitted through nose or mouth
- Reflected sounds received by the ears
- Many species have fleshy projections on nose and/or ears, thought to help with echolocation


Identification of Chiroptera

- Forelimb modified to form wing capable of self-powered flight
- Metacarpals and phalanges of digits 2-5 elongated and connected by a patagium
- First digit of manus always clawed
- Well-developed clavicle
- Sternum often keeled
- Short hindlimbs are rotates 90-180 degrees from typical mammalian posture
- All digits on pes have claws



Portion of the patagium that extends between the hind legs and incorporates the tail, if present



Cartilaginous spur that extends medially from the ankle of the hind foot and supports the membrane of the uropatagium



Flap or projection of the nose, present in many echolocating bats



Fleshy lobe that projects from the lower medial corner of the pinna, present in most echolocating bats



Flap on the lower lateral edge of the pinna, especially well-developed in echolocating bats with no tragus


Identification of Pteropodids

- Face fox-like to lemur-like
- Eyes large
- Nose usually unspecialized, no noseleaf
- Tragus absent
- Postorbital process well-developed
- Wing has claws on first and second digits
- Simplified cusps on cheek teeth


Identification of Non-pteropodids

- Capable of echolocating using sounds produced in the larynx
- Eyes often reduced
- Tragus present (minus two families)
- Wing has claws on digit 1
- Calcar supporting uropatagium
- Large ears
- W-shaped ectoloph on cheek teeth
- Large gaps in premaxilla



Family within Soricomorpha
Contains 6 Ontario species:
- Blarina brevicauda
- Cryptotis parva
- Sorex cinereus
- Sorex fumeus
- Sorex hoyi
- Sorex palustris


Blarina brevicauda

Northern short-tailed shrew
- Largest shrew in N.A.
- Makes shallow burrows in soil, leaf litter, even snow
- Makes nests in said burrows that are lined in grass and fur
- Active mostly at night or early morning
- Poisonous saliva can paralyze prey
- Diet of invertebrates - worms, snails, etc.
- Active year-round
- Lives less than a year
- Most common in hardwood forests with deep leaf litter


Identification of Blarina brevicauda - Skull

- Mental foramen located under posterior cusp of fourth lower tooth
- Base of first lower incisor located behind anterior margin of fourth lower tooth
- More than three unicuspids readily visible in lateral view of upper jaw


Identification of Blarina brevicauda - Skin

- Total length greater than 95 mm
- Tail length less than 30% of total length
- Ears small and concealed by fur
- Eyes have bare patch of skin surrounding
- Long claws on front feet


Cryptotis parva

Least shrew
Fairly common
- Eats a variety of invertebrates
- Fairly social for a shrew
- Prefers overgrown fields and brush


Identification of Cryptotis parva - Skull

- No medial tine on first upper incisor
- Four upper unicuspids evident in ventral view; fourth hidden in lateral


Identification of Cryptotis parva - Skin

- Tail length less than 30% total length
- Total length less than 95 mm
- Back dull brown to nearly black
- Underside grey-brown to silver
- Ears very small and concealed by fur


Sorex cinereus

Masked shrew
Common and widespread
- Travels on the surface or under leaf litter
- Feeds on small invertebrates/vertebrates
- Lifespan: ~15 months
- Lives in a variety of habitats


Identification of Sorex cinereus - Skull

- Greatest length of skull less than 17.5mm
- Five upper unicuspids, fifth smaller but still visible


Identification of Sorex cinereus - Skin

- Tail long, greater than 30% total length
- Black/brown, underside paler than back
- Tail bicoloured with distinct black tuft
- Hind foot length usually 10mm or more, but less than 16mm
- Total length less than or equal to 100mm
- Feet and toes do not have fringe of whitish hairs


Sorex fumeus

Smoky shrew
Fairly common
- Travels in tunnels under leaf litter and rotting logs
- Feeds on medium-sized invertebrates and salamanders
- Lifespan: 14-17 months
- Lives in moist areas in hardwood and coniferous forests


Identification of Sorex fumeus - Skull

- Third unicuspid usually larger than fourth in lateral view
- Greatest length of skull more than 20.5mm
- Four unicuspids readily visible in lateral view


Identification of Sorex fumeus - Skin

- Summer coat: back grey-brown, underside pale brown
- Winter coat: back dark grey, underside pale grey
- Ears conspicuous
- Tops of feet whitish
- Tail bicoloured with slight tuft at tip
- Total length greater than 100mm, but less than 130mm
- Hind foot length less than 16mm- Tail length greater than 30% total length


Sorex hoyi

Pygmy shrew
- Makes tiny burrows under leaf litter and near soil surface
- Feeds on small arthropods, worms, carrion, and some plant material
- Lives in variable habitats


Identification of Sorex hoyi - Skull

- Only three unicuspids visible in lateral view (3rd and 5th tiny)
- 3rd and 5th unicuspids visible in ventral view
- First upper incisor has medial tine


Identification of Sorex hoyi - Skin

- Back dull smoky brown to bright copper brown
- Underside pale grey-brown (summer), whitish (winter)
- Tail bicolour, greater than 30% total length
- Hind foot usually 10mm or less
- Total length less than or equal to 100mm


Sorex palustris

American water shrew
- Swims well
- Appears silver in water because fur traps air, increasing buoyancy
- Hairs on hind feet trap air, allowing it to run across the water surface
- Eats aquatic insect larvae, small fish, terrestrial invertebrates
- Max. lifespan 18 months


Identification of Sorex palustris - Skull

- More than 3 unicuspids readily visible in lateral view
- Third unicuspid usually smaller than fourth in lateral view
- Greatest length of skull more than 20.5mm


Identification of Sorex palustris - Skin

- Total length greater than 130mm
- Long, bicoloured tail, greater than 30% total length
- Back blackish, sometimes flecked with white
- Underside silvery white or buffy brown
- Feet large, greater than 16mm
- Toes on hind foot partially webbed
- Hind feet fringed on sides with white hair


Condylura cristata

Star-nosed mole
Common locally
- Swim well
- Makes tunnels leading to water
- Shallow or deep burrows
- Active on and under snow
- Feeds on aquatic invertebrates and small fish
- Star on nose used to detect electric fields of earthworms and other prey in water
- Lives in wet areas in meadows, woods, swamps, streams


Identification of Condylura cristata - Skull

- First upper incisor points down and foreward
- First lower incisor points forward
- Palate ends opposite to or in front of last upper cheek tooth


Identification of Condylura cristata - Skin

- Has 22 fleshy, tentacle-like appendages around the tip of the snout
- Nostrils face downward
- Tail long and well haired, thick at base and tapers to point at tip


Parascalops breweri

Hairy-tailed mole
Common locally
- Active day or night
- Digs shallow tunnels that form inconspicuous ridges in the soil
- Moves deeper underground in fall
- Eats earthworms and incects, esp. beetles
- Lives in deciduous and coniferous woods, oldfields, roadsides with light, well-drained soil


Identification of Parascalops breweri - Skull

- Auditory bullae incomplete (partially open on bottom)
- 11 teeth in each half of the lower jaw
- Greatest width of skull less than 16mm
- First upper incisor essentially vertical
- Palate ends just in back of last upper cheek tooth


Identification of Parascalops breweri - Skin

- Long, narrow snout
- Nostrils open at side of snout
- Tail has long, coarse hair (5mm +)
- Hindfeet less than 21mm long


Scalopus aquaticus

Eastern mole
Common locally
- Burrows create prominent ridges on soil surface
- Uses deep tunnels in winter
- Digs with front feet but also pushes dirt with snout
- Produces large mole hills when excavating deep tunnels
- Eats earthworms and other invertebrates, also plant material
- Lifespan 6 years or more
- Lives in fields or woods with soft, moist soils


Identification of Scalopus aquaticus - Skull

- Auditory bullae complete
- Eight teeth in each lower jaw
- Greatest width of skull more than 16mm
- First upper incisor vertical
- Palate ends in back of last upper cheek tooth


Identification of Scalopus aquaticus - Skin

- Narrow snout
- Nostrils open on top of snout
- Tail sparsely furred or naked
- All feet webbed
- Feet have hairy fringe
- Hind foot length greater than 21mm


Lepus americanus

Snowshoe hare
Common locally
- Populations in the north fluctuate greatly on a 10-year cycle
- Mostly nocturnal or crepuscular; seeks shelter by day
- Eats grass, green vegetation, and berries in summer; mostly twigs and bark in winter
- Lives in forests and dense thickets


Identification of Lepus americanus - Skull

- Greatest length of skull less than 88mm


Identification of Lepus americanus - Skin

- Upper parts brown-dark brown in summer, with dorsal hairs slate grey at base
- Entirely white in winter, except for black ear tips
- Hind feet very long, heavily furred
- Tail length less than 50mm


Identification of Hares

- Shield-shaped supraoccipital region higher than wide
- No discernible boundaries on the interparietal
- Posterior border of supraoccipital process not touching cranium


Identification of Rabbits

- Shield-shaped supraoccipital region wider than high
- Discernible boundaries on interparietal
- Posterior border of supraoccipital process in contact with cranium


Lepus europaeus

European hare
Populations declining in N.A.
- Mainly nocturnal or crepuscular
- Tries to outrun predators instead of seeking shelter
- Feeds on green vegetation, seeds, berries in summer; twigs and bark in winter
- Lives in meadows, pastures and cultivated fields
- Introduced


Identification of Lepus europaeus - Skull

- Greatest length of skull more than 88mm


Identification of Lepus europaeus - Skin

- Ears long with black tip
- Tail length greater than 50mm
- Tail dark above and white below
- Tail held down when running
- Legs, feet and lower sides orange-brown, snow white at base with black band before brown tip


Sylvilagus floridanus

Eastern cottontail
- Mainly nocturnal, may be active at dusk/dawn
- Eats herbaceous plants in summer, woody plants in winter
- Lives in thickets and oldfields, edges of hardwood forests, farmland, prairies, swamps


Identification of Sylvilagus floridanus - Skull

See identification of rabbits


Identification of Sylvilagus floridanus - Skin

- Back orange grizzled with black, sides paler and greyer, underside white
- Nape usually deep orange/rusty/cinnamon brown
- Cream coloured ring around eye
- Tail white below
- Hind foot length less than 115mm



Family within Lagomorpha
Includes rabbits and hares



Family within Chiroptera
Vesper bats
Only family found in Ontario


Eptesicus fuscus

Big brown bat
Common, widespread
- Emerges about a half hour after sunset
- Feeds on beetles and other insects
- Hunts over fields/streams, under street lamps
- Common house bat in the east
- Migrates short distances in fall to hibernate in caves, mines, attics
- During hibernation, will still wake up and become active in response to temperature changes
- Lives in forests, farms and cities


Identification of Eptesicus fuscus - Skull

- Four upper cheek teeth on each side
- Greatest length of skull 17.5mm or more
- Two upper incisors on each side


Identification of Eptesicus fuscus - Skin

- Fur on back glossy and yellowish or dark brown
- Tragus broad and curved
- Tail tip extends beyond uropatagium
- Keeled calcar
- Forearm length greater than 40mm
- Total length greater than 105mm


Lasionycteris noctivagans

Silver-haired bat
- Emerges soon after sunset
- Has characteristic slow flight, sometimes following repeated circuit
- Mating occurs after fall migration
- Hibernation sites not well known
- Lives in forest and forest edge, usually near waterways


Identification of Lasionycteris noctivagans - Skull

- Shallow depression extending forward and medially from each orbit to nostril opening
- Two upper incisors on each side
- Five upper cheek teeth on each side, first is much smaller than second in lateral view
- Six lower cheek teeth on each side
- Greatest length of skull more than 14mm, less than 17.5mm


Identification of Lasionycteris noctivagans - Skin

- Fur brown to black; has white- or silver-tipped hairs
- Uropatagium only furred on dorsal surface for 25-50%
- Total length less than 120mm
- Forearm length less than 44mm


Lasiurus borealis

Eastern red bat
- Emerges early in the night
- Fly swiftly and often follow same path each night
- Eats moths and other insects
- Migrates south in fall, may swarm at cave entrances but hibernates amongst foliage
- Has also been found hibernating on the ground in leaf litter
- Lives in forests and on forest edges


Identification of Lasiurus borealis - Skull

- Greatest length of skull 15mm
- One upper incisor on each side


Identification of Lasiurus borealis - Skin

- Overall fur colour brick red to yellowish red


Lasiurus cinereus

Hoary bat
Common in western Ontario, uncommon in eastern Ontario
- Fast, direct flight
- Mainly eats moths, may attack small bats and other insects
- Feeds over streams and ponds, around streetlights
- Migrates long distances
- Winter roosts include sides of buildings and tree trunks
- Lives in deciduous and coniferous forests


Identification of Lasiurus cinereus - Skull

- Greatest length of skull 16mm or more
- One upper incisor on each side


Identification of Lasiurus cinereus - Skin

- Fur has four bands; outer layer brown and heavily frosted with white
- Yellow fur around face
- Uropatagium thickly furred on upper surface


Myotis leibii

Eastern small-footed myotis
Rare but poorly known
- Emerges at dusk to forage
- Flight slow and erratic
- Hibernates in winter
- Lives in deciduous and coniferous forests


Identification of Myotis leibii - Skull

- Greatest length of skull usually less than 14.1mm
- Least interorbital width less than 3.4mm
- Two upper incisors on each side
- Six upper cheek teeth on each side
- First and second upper cheek teeth equal in size in lateral view
- First and second upper cheek teeth smaller than third in lateral view


Identification of Myotis leibii - Skin

- Light brown fur with distinct black facial mask
- Very small
- Keeled calcar
- Hind foot length 8mm or less
- Forearm length less than 34mm
- Total length less than 85mm
- Tragus not sharply pointed
- Tragus less than 8mm in height
- Ear height 16mm or less
- Uropatagium not furred at all


Myotis lucifugus

Little brown bat
Very common
- Emerges at dusk or later
- Usually flies straight to water to forage and drink; may also forage above trees
- Feeds mainly on emerging aquatic insects, including some mosquitoes
- Consumes half its body weight in insects each night
- Hibernates in winter
- Lives in forests and rural areas, usually near streams and lakes
- Typically roosts in houses and other man-made structures


Identification of Myotis lucifugus - Skull

- Least interorbital width usually 4mm or more
- Greatest width of braincase usually 7.3mm or more
- Greatest length of skull usually 14.1mm or more
- Two upper incisors on each side
- Six upper cheek teeth on each side
- First and second upper cheek teeth equal in size in lateral view
- First and second upper cheek teeth smaller than third in lateral view


Identification of Myotis lucifugus - Skin

- Fur on back glossy, yellowish-brown
- Underside buff yellow or grey-white
- No obvious face mask
- Tragus straight and narrow
- Tragus not sharply pointed
- Tragus less than 8mm in height
- Ear height 16mm or less
- Forearm length greater than 34mm
- Hind foot length 8mm or more
- Calcar not obviously keeled
- Total length greater than 85mm
- Uropatagium not furred at all


Myotis septentrionalis

Northern long-eared myotis
Locally common and widespread
- Forages in upland forests
- Flies near understory vegetation
- Catches flying insects and grabs prey from vegetation
- Hibernates in small crevices in caves
- Lives in wooded areas


Identification of Myotis septentrionalis - Skull

- Least interorbital width usually less than 4mm, greater than 3.4mm
- Greatest width of braincase 7.3mm or less
- Greatest length of skill greater than 14.1mm
- Two upper incisors on each side
- Six upper cheek teeth on each side
- First and second upper cheek teeth equal in size in lateral view
- First and second upper cheek teeth smaller than third in lateral view


Identification of Myotus septentrionalis - Skin

- Back dark brown, yellow-brown, or blond
- Scruffy looking
- Hair dark to roots
- Ears long (16mm or more)
- Tragus long (8-9mm) and narrow, with pointed tip
- Calcar not keeled
- Uropatagium not furred at all


Pipistrellus subflavus

Eastern pipistrelle
- Emerges at sunset
- Flight slow and erratic
- Feeds on tiny flies and beetles
- Hunts over water and at forest edge
- Hibernates in caves and mines from November to April
- Lives in woodland or mixed farmland


Identification of Pipistrellus subflavus - Skull

- Five upper cheek teeth on each side
- First upper cheek tooth much smaller than second
- Two upper incisors on each side
- Five lower cheek teeth on each side
- Greatest length of skull less than 14mm


Identification of Pipistrellus subflavus - Skin

- Body hairs tricoloured: black at base, yellowish brown along shaft, dark brown/black at tip
- Proximal third of dorsal uropatagium furred
- Hairs on dorsal surface of feet and toe sharply contrasting with black underlying skin



Order within Glires
- Approx. 42% all mammals
- Rootless, arc-shaped, chisel-edged incisors
- Mostly omnivorous


Identification of Rodentia

- Single arc-shaped incisor in each jaw quadrant
- Sharpness of chisel edge of each incisor maintained by differential wear on the anterior enamel and dentine that makes up the bulk of the tooth
- Canines, majority/all premolars absent
- Cheek teeth range from 0-24
- Cheek teeth ever growing in some families
- Mandible moves anteroposteriorly in addition to laterally
- Incisors and cheek teeth cannot be occluded simultaneously
- Most are small
- External tail present (some exceptions)
- Well haired (except naked mole rat)
- Mostly quadrupedal, with some arid species capable of ricochetal locomotion
- Digits may be reduced to 4/3 instead of the usual 5/5
- Can be distinguished from wombats by lack of angular process of the ramus
- Can be distinguished from aye-ayes by lack of postorbital bar and posterior position of the foramen magnum
- Can be distinguished from lagomorphs and hyraxes by reduced number of incisors



Masseter originates in front of the orbit and does not pass through the small infraorbital foramen
- Zygomatic arch extends and flares outward, forming a "zygomatic plate"
- Generally gnaw with incisors



Masseter pushes up through the orbit and passes through the infraorbital foramen
- Infraorbital foramen V, oval or round shaped
- Retains somewhat expanded zygomatic arch- Intermediate between sciuromorphous and hystricomorphous
- Found in most rodents



Masseter very well developed, passes through greatly enlarged infraorbital foramen
- Generally grind with molars



Order within Ferae, contains:
- Feliformia
- Caniformia (& Pinnipedia)

- Mostly predaceous
- Keen sense of smell
- Great range of size
- Ambulatory, cursorial, arboreal, semiaquatic, semifossorial



Group within Laurasiatheria, contains:
- Carnivora
- Pholidota



Term used for all non-pinniped carnivorans
- i.e. Feliformia + (Caniformia - Pinnipedia)
- Generally only found on continental land masses or freshwater, with the exception of polar bear, sea otter and S.A. marine otter



Suborder within Carnivora
Cats, civets/genets, hyaenas, mongooses, Malagasy carnivores



Suborder within Carnivora
Dogs/wolves, bears, pinnipeds, mustelids



Group within Caniformia
Seals, sea lions, walrus
- Found literally everywhere
- Mostly marine


Identification of Carnivora

- Canines usually large and conical
- Incisors usually 3/3, but 3/2 in sea otters and lowers 0-2 in Otariidae & Phocidae
- Secodont cheek teeth in most fissipeds; may be adapted for crushing or reduced
- Third upper molar (M3) never present
- Large, complex turbinals
- Well-developed zygomatic arches
- Sagittal crest frequently present
- Mandibular condyle/fossa transversely elongated, limited lateral movement
- Auditory bullae usually fully ossified, usually large
- Toes in fissipeds ending in large, curved claws


Carnassials (Adult)

Last upper premolar (P4)
First lower molar (m1)


Carnassials (Juvenile)

Next-to-last upper premolar (P3)
Last lower premolar (p4)


Identification of Feliformia

- Auditory bullae two-chambered; joined by a septum
- Claws strong and sharp
- Claws semi or fully retractile (in sheath of skin when retracted)
- Rostrum tends to be short
- Cheek teeth reduced
- Carnassials highly developed for cutting


Identification of Caniformia

- Auditory bullae not divided by septa; may be partially chambered
- Claws never fully retractile, may be semi
- Rostrum longer
- More cheek teeth than feliforms
- Carnassials may be smaller than feliform


Identification of Pinnipedia

- Body insulated with thick layer of blubber; may also be covered in hair
- Body fusiform, adapted for swimming
- Digits covered with skin to form flippers
- Forelimbs & hindlimbs paddle-like
- Pinnae highly reduced or absent
- Vibrissae well developed
- Premolars & molars homodont
- Tail short or absent
- External genitalia hidden in slits/grooves



Family within Rodentia
Squirrels, chipmunks, woodchucks (6 sp.)



Family within Rodentia
Beaver (1 sp.)



Family within Rodentia
New World rats/mice (7 sp.)



Family within Rodentia
Old World rats/mice (2 sp.)



Family within Rodentia
Jumping mice (2 sp.)



Family within Rodentia
New world porcupines (1 sp.)


Identification of Sciuridae (Skull)

- Postorbital process present on frontal bone, sharply pointed
- Infraorbital foramen smaller than foramen magnum
- Total length of skull usually less than 95mm


Identification of Sciuridae (Skin)

- Tail well furred & often bushy
- Longest tail hairs much longer than width of tail vertebrae, always >10mm
- Hind feet less than 2.5x forefeet


Glaucomys sabrinus

Northern flying squirrel
Widespread, common
- Nocturnal/crepuscular
- Mainly arboreal
- Active year-round
- Mainly eats nuts, seeds, tree sap, fungi, lichens
- Will also eat birds' eggs, nestlings, mice, insects, carrion (more carnivorous than other squirrels)
- Usually nests in tree cavities, also makes nests of leaves & twigs that are lined
- Usually solitary (may share in winter)
- Lives mainly in coniferous forests/mixed woods up to tree line


Identification of Glaucomys sabrinus (skull)

- GL 36mm - 40mm; GW >21.5mm; L upper row of cheek teeth >7mm
- Two internal divisions of auditory bullae visible externally
- Infraorbital foramen not visible in ventral view & anterior to first well-formed cheek tooth


Identification of Glaucomys sabrinus (skin)

- Hairs of underside slate coloured at base
- Has patagium


Glaucomys volans

Southern flying squirrel
- Greater reliance on nuts and less on fungi than G. sabrinus
- Stores nuts for consumption during winter
- Lives mainly in deciduous forests of oak-hickory or beech-maple


Identification of Glaucomys volans (skull)

- GL skull <7mm
- Two internal divisions of auditory bullae visible externally
- Infraorbital foramen not visible in ventral view & anterior to first well-formed cheek tooth


Identification of Glaucomys volans (skin)

- Hairs of underside completely white
- Has patagium


Marmota monax

Woodchuck (groundhog)
Widespread & common
- Active in early morning & late afternoon
- Makes extensive burrows with several entrances & exits (summer)
- Winter den has single entrance
- Can climb to forage or view surroundings
- Eats mostly green vegetation, some crops
- Occasionally makes sharp whistling noise
- Hibernates for 3-6 months in winter
- Lives in fields and brush @ forest edge; along highways/roadsides


Identification of Marmota monax (skull)

- Top of skull almost flat in outline
- Incisor usually white or pale yellow
- Postorbital process @ 90 degree angle to long axis of skull


Identification of Marmota monax (skin)

- Claws on middle digits of forefoot long (max. length obviously >50% fleshy portion of digits)
- Large
- Solid colour


Sciurus carolinensis

Eastern grey squirrel
Common as dirt (most familiar mammal in E. N. America)
- Mainly arboreal but will spend quite a bit of time on ground esp. in fall/winter
- Eats nuts, acorns, buds, flowers, fungi, fruit, seeds; occasionally insects/small birds
- Caches nuts & acorns for winter; buried individually and later located by scent
- Nests of leaves, twigs, etc. on branches or inside hollow trees
- Solitary in summer, may group in winter
- Active year-round


Identification of Sciurus carolinensis (skull)

- GL >50mm
- Auditory bullae have two septa that may or may not be externally visible
- Infraorbital foramen not visible in ventral view & anterior to first well-formed cheek tooth


Identification of Sciurus carolinensis (skin)

- Total length >375mm
- No ear tufts, black side stripe
- Claws on middle digits of forefoot not elongated


Tamias striatus

Eastern chipmunk
Common, abundant
- Usually calls from raised vantage point
- Climbs well
- Will forage in trees or on the ground
- Eats a variety of seeds, fruit, fungi, animals
- Elaborate burrow systems; up to 30m of tunnels, multiple entrances
- Gathers and stores large quantities of food in burrow in fall
- May hibernate in winter depending on latitude
- Lives in deciduous forest, forest edge, gardens, suburban areas


Identification of Tamias striatus (skull)

- Infraorbital foramen visible in ventral view
- Infraorbital foramen positioned forward and lateral of first well-formed cheek tooth


Identification of Tamias striatus (skin)

- Alternating light and dark stripes on back (5)


Tamiasciurus hudsonicus

Red squirrel
Widespread, common
- Very vocal; may repeat sharp alarm bark for upwards of an hour
- Active year-round
- Feeds mainly on pine seeds; also nuts, fungi, fruit, tree sap, young birds, eggs
- Hordes pine cones in large piles
- Prefers to nest in tree cavities; also branches, underground
- Solitary
- Lives in coniferous forests, mixed forests, orchards, parks


Identification of Tamiasciurus hudsonicus (skull)

- Auditory bullae have 3 septa visible externally
- Greatest length of skull 40mm - 50mm
- Infraorbital foramen not visible in ventral view & positioned anterior to first well-formed cheek tooth


Identification of Tamiasciurus hudsonicus (skin)

- Red in colour
- Black ear tufts in winter only
- Black stripe separating back from light underside in summer only
- Total length <375mm
- Claws on middle digits of forefoot not elongated


Castor canadensis

American beaver
Widespread, common/abundant
Populations once exploited for fur recovered
- Semiaquatic
- Swims with eyes & nose exposed; body and tail usually below water
- Warning slaps on water with tail
- Fells trees & builds dams to store wood and keep water levels high enough in winter to maintain open water below ice
- Mainly crepuscular & nocturnal
- Active year-round
- Can remain under water for 15 min
- Eats roots and green vegetation in summer; bark in winter
- Will burrow along banks in rivers
- Family groups: monogamous pair, yearlings, young from previous year
- Marks territory with anal & castor glands
- Lives in swamps, lakes, rivers, streams in wooded areas; ponds in tundra


Identification of Castor canadensis (skull)

- Ear opening at the end of an upward curving tube
- Greatest length >115mm


Identification of Castor canadensis (skin)

- Tail naked, scaly & paddle-shaped
- Width of tail >25% length- Total length >650mm


Identification of Cricetidae (skull)

- Occlusal surface of cheek teeth have whitish enamel loops surrounding patches of dentine; outer margins have zig-zag appearance (1 exception)
- Infraorbital foramen narrower at bottom; often V-shaped; faces forward or laterally
- Upper incisors can be plain or grooved
- Postorbital process absent


Identification of Cricetidae (skin)

- Tail never bushy
- Length of longest tail hairs less than width of tail vertebrae; less than 10mm


Microtus pennsylvanicus

Meadow vole
Abundant, widespread
- Active night & day
- Swims well but cannot climb
- Frequently seen dashing across roads; forms networks of runways through grass
- Eats green plant material, bark, roots, tubers
- Females solitary & territorial in summer; shared nests in winter
- Males move freely year-round
- Nest aboveground under clumps of grass
- Live in damp meadows, roadsides, orchards, anywhere with thick cover of grass


Identification of Microtus pennsylvanicus (skull)

- Three re-entrant angles on either side of posterior upper cheek tooth
- Posterior border of palate supported at midline (perforated)
- No longitudinal groove on front lateral surface of upper incisor- GL <35mm


Microtus pinetorum

Woodland vole
Locally common/abundant
- Mostly lives subterranean
- Makes burrows under leaf litter and in shallow soil
- Eats roots year-round; summer grass stems; fall fruits; winter bark
- Lives in small family groups
- Monogamous
- Lives in deciduous forests with thick leaf litter or grassy patches in woodlands/orchards; dense brush
- Favours sandy soils


Identification of Microtus pinetorum (skull)

- Two re-entrant angles on either side of posterior upper cheek tooth
- Posterior border of palate supported at midline (perforated)
- No longitudinal groove on front lateral surface of upper incisor- GL <35mm


Identification of Microtus pennsylvanicus (skin)

- Tail length <50% head+body length
- Pinnae mostly hidden by fur
- Back dark brown, sides brown/grey-brown, underside grey-white
- Thick, coarse fur
- Tail relatively long and lightly haired


Identification of Microtus pinetorum (skin)

- Fur has reddish tint along back and sides
- Dorsal hairs velvety & mole-like
- Incisors do not have longitudinal grooves
- Tail similar in length to hind foot


Myodes gapperi

Southern red-backed vole
Widespread & common
- Mainly diurnal in winter, mainly nocturnal in summer
- Does not construct underground burrow system but travels under leaf litter & fallen logs
- Eats fungi, seeds, nuts, berries, lichen; some arthropods
- Globular nests in burrows or under logs
- Lives in damp forests, mountain meadows, clear-cuts and bogs


Identification of Myodes gapperi (skull)

- Posterior border of palate shelf-like & not supported at the midline (no perforations)
- No longitudinal groove on front lateral surface of upper incisor- GL <35mm


Identification of Myodes gapperi (skin)

- Reddish-brown head & back; greyish-brown sides; distinctive stripe
- Tail bicoloured, nearly naked, longer than hind foot
- Tail has small tuft at tip
- Ears conspicuous


Peromyscus maniculatus

American deer mouse
Adundant & widespread
- Mainly terrestrial, but some climb well
- Eats seeds, fruit, insects, subterranean fungi, etc.
- Stores excess food in caches
- Solitary in summer, may huddle in winter in the north
- Occupies all habitat types


Identification of Peromyscus maniculatus (skull)

Indistinguishable from P. leucopus
- Cheek teeth have two longitudinal rows of cusps at midtooth
- Cheek teeth have low rounded cusps; outer margins have no zigzag appearance


Identification of Peromyscus maniculatus (skin)

- Pure white chin patch 50% head+body length


Peromyscus leucopus

White-footed mouse
Abundant & widespread
- Mainly terrestrial but climbs and swims well
- Eats insects, seeds, nuts, fruit & green veg
- Stores food under logs or near nest sites
- Will often live in homes in wooded areas
- Lives in deciduous and mixed forest, hedgerows, bushy areas, croplands, semidesert


Identification of Peromyscus leucopus (skull)

Indistinguishable from P. maniculatus
- Cheek teeth have two longitudinal rows of cusps at midtooth
- Cheek teeth have low rounded cusps; outer margins have no zigzag appearance


Identification of Peromyscus leucopus (skin)

- Pure white chin patch extends >1cm from mouth- Tail lightly haired, no tuft @ tip
- Back clearly two-toned
- Fur smooth and slightly shiny
- Underside fur grey @ base (1/4) & white @ tip (3/4); appears pure white in living


Ondatra zibethicus

Common muskrat
Common & widespread
- Semiaquatic; swims well
- Top of head, upper back & sometimes tail visible when swimming
- Slaps water when alarmed
- Mainly nocturnal; also active on overcast or rainy days
- Eats cattail and other aquatic plants
- Can close lips behind incisors to harvest food underwater without taking in water
- Makes a lodge or house out of cattail/sedges in shallow water
- Accesses lodge via underwater tunnels
- May make nest in bank burrow
- Males have scent glands on either side of penis; mark glands


Identification of Ondatra zibethicus (skull)

- Greatest length of skull >35mm
- Cheek teeth have series of white enamel loops surrounding patches of dentine; outer margins have zigzag appearance


Identification of Odontra zibethicus (skin)

- Hind feet webbed
- Tail laterally compressed & naked
- Total length greater than 450mm


Synaptomys cooperi

Southern bog lemming
Common but patchily distributed
- Mainly nocturnal but sometimes active by day
- Makes runways through grass or may travel through mole tunnels
- Eats mostly grasses and sedges; also fungi, berries, moss
- Live in colonies of 3-30 individuals
- Usually make nests in underground burrows
- Lives in various places but usually near green grass or sedge


Identification of Synaptomys cooperi (skull)

- Shallow longitudinal groove on front lateral surface of upper incisor
- Greatest length of skull <35mm


Identification of Synaptomys cooperi (skin)

- Fur grizzled brown to black along sides
- Fur somewhat shaggy
- Many dorsal hairs >10mm
- Incisors have longitudinal groove
- Tail similar in length to hind foot


Identification of Dipodidae (skull)

- Infraorbital foramen large & faces forward; oval-shaped
- Pin-sized opening located directly below infraorbital foramen
- Upper incisors have single longitudinal groove on anterior surface


Identification of Dipodidae (skin)

- Hind feet large; about 2.5x forefeet
- Tail round, scaly
- Tail longer than head+body
- Total length <260mm


Napeozapus insignis

Woodland jumping mouse
Uncommon to locally common
- Mainly nocturnal, sometimes come out in overcast weather
- May stay motionless when encountered
- Can leap up to 3m if startled
- Eats seeds, berries, subterranean fungi, insects, insect larvae
- Hibernates for 6-8 months (Oct-May)
- Weight just before hibernation 150% spring weight


Identification of Napeozapus insignis (skull)

- Three upper cheek teeth; all well-formed


Identification of Napeozapus insignis (skin)

- Last 5mm or so of tail white
- Sides & cheeks yellow-orange or reddish-brown
- Back and head dark brown
- Underside pure white
- Hind feet very long and narrow


Zapus hudsonius

Meadow jumping mouse
- Mainly nocturnal
- Swims well both above and below water
- May cross bodies of open water
- Can leap up to 1m, but usually moves in short hops or crawls
- Eats grass, seeds, fruit, fungi and insects (esp. moth larvae)
- Hibernates for 6-8 months (Oct-May) in southern part of range, up to 10 months in northern part of range
- Weight before hibernation ~150% spring
- Hibernates in nests of grass & leaves, usually 0.5m below ground
- Lives in grassy or weedy fields (both dry and wet), forest clearings, along streams/bogs/forest edge
- Favours areas with dense herbaceous vegetation


Identification of Zapus hudsonius (skull)

- Four upper cheek teeth; first small and peg-like


Identification of Zapus hudsonius (skin)

- Tail tip dark; similar in colour to proximal
- Lateral fur brightly coloured and often yellowish orange


Erethizon dorsatum

North American porcupine
Common & widespread
- Mainly nocturnal, sometimes seen along roadsides during the day
- Active year-round
- Eats tree buds in spring, tree leaves & herbaceous plants in summer; acorns, beechnuts, apples, leaves in fall; inner bark of trees & conifer needles in winter
- Craves salt and will chew plywood, stalk roadsides
- Females and young den in winter
- Males may den or spend time in trees year-round
- When attacked, flicks tail to drive short, thin quills into attacker
- Quills are not thrown
- Lives in deciduous and coniferous forests


Identification of Erethizon dorsatum (skull)

- Infraorbital foramen as large or larger than foramen magnum
- Skull large; total length 95mm - 115mm


Identification of Erethizon dorsatum (skin)

- Some hairs modified into sharp, pointed quills


Mus musculus

House mouse
Common and widespread
Origin of the white lab mouse
- Nocturnal
- Mainly terrestrial, but climbs well
- Eats grains, seeds, insects as well as things left by humans
- Nests in underground burrows in fields; also in buildings
- Lives in agricultural areas, roadsides, buildings in rural/urban areas


Identification of Mus musculus (skull)

- Greatest length of skull <25mm
- Tip of upper incisor distinctly notched in lateral view


Identification of Mus musculus (skin)

- Total length <200mm
- Tips of most hairs of underside grey, tan, brown


Identification of Muridae (skull)

- Cheek teeth have three longitudinal rows of cusps at midtooth


Identification of Muridae (skin)

- Tail naked or furred; longer than hind foot
- Length of longest hairs generally less than width of tail vertebrae; always less than 10mm
- Tips of most hairs of underside grey, tan, brown


Rattus norvegicus

Norway rat
Used in labs
- North America's most serious pest
- Mainly nocturnal
- Terrestrial but can climb and swim well
- Eats grain, fruit, garbage - anything available
- Has been known to kill chickens
- Lives in colonies with one male and several females + young
- Lives in complex burrow system
- Lives in urban areas, grain fields, salt marshes
- Favours sewers and wet areas in cities



Family within Caniformia
Dogs, wolves, coyotes (4 sp.)



Family within Feliformia
Cats (2 sp.)



Family within Caniformia
Skunks (1 sp.)



Family within Caniformia
Otters, weasels, badgers (8 sp.)



Family within Caniformia
Raccoons (1 sp.)



Family within Caniformia
Bears (1 sp.)


Identification of Canidae (skull)

- Posterior border of palate even with last tooth or slightly behind
- Seven lower cheek teeth


Identification of Canidae (skin)

- Body dog-like
- Claws straight & somewhat blunt
- Claws not retractile
- Scent gland present on back at dorsal base of tail
- Tail long and bushy; greater than 200mm


Canis latrans

Common & widespread
- Highly adaptable
- Most active at dusk/dawn in east; nocturnal or diurnal in west
- Usually runs with tail downward
- Eats a variety of foods including small mammals, birds, snakes, insects, fruit, berries, veggies
- Usually feeds on larger prey (i.e. deer) as carrion, but may hunt cooperatively in groups
- May travel alone or in pairs
- Packs of 3-7 consists of a mated pair and offspring of various ages
- Larger packs are unstable associations of nonbreeding animals
- Packs will defend territories of 10-24 km^2
- Mark boundaries of territory with urine
- Most commonly found in mixed habitats, less common in large areas of unbroken forest


Identification of Canis latrans (skull)

- Greatest length of skull <225mm
- Base of postorbital processes smooth or convex with no paired depressions


Identification of Canis latrans (skin)

- Total length 1,075 - 1,350 mm
- Hind foot <33% total length
- Long legs
- Large ears
- Long, narrow muzzle
- Legs and muzzle rusty in colour
- Body colour varies from greyish to tawny
- Tail bushy and usually tipped black


Canis lycaon

Eastern timber wolf
Exact numbers unknown
- Mainly active at dawn/dusk, but sometimes day
- Eats mostly large mammals: moose, white-tailed deer, elk, caribou, sheep; sometimes beaver and showshoe hare
- Most social of the canids: lives in packs of 2-15 (avg. 6)
- Packs composed of family members
- Packs have well-defined social hierarchy, with male/female dominating all other males/females in group
- Home range of 146-2600 km^2
- Favours heavily forested areas


Identification of Canis lycaon (skull)

- Greatest length of skull >225mm
- Base of postorbital processes smooth or convex with no paired depressions


Identification of Canis lycaon (skin)

- Total length >1,350 mm
- Hind foot >225 mm
- Width of nosepad >25 mm
- Tail length <33% total length
- Muzzle tapered but not as long as coyote
- Back grey-brown to reddish-brown
- Lower sides and legs tawny
- Chest and underside greyish white
- Tail with black tip


Urocyon cinereoargenteus

Grey Fox
Common in US
Hunted and trapped for fur in range
- Mainly nocturnal/crepuscular
- Usually seen on the ground but is capable of climbing trees to feed or escape predators
- More omnivorous than other foxes
- Feeds mostly on small mammals in winter and may eat lots of insects in summer
- Range 2-5 km^2
- Seen alone or pairs
- Lives in deciduous forest and oldfields (east)
- Brush areas and riparian forest (west)


Identification of Urocyon cinereoargenteus (skull)

- Temporal ridges form U shape when viewed from above
- Lower part of mandible notched at posterior end


Identification of Urocyon cinereoargenteus (skin)

- Body a mixture of grey & black
- Sides rust-orange
- Underside & throat white
- Feet not black
- Tail has black tip and top
- Tail length >33% total length
- Total length <1,075 mm
- Relatively short legs


Vulpes vulpes

Red fox
Common - has expanded in range due to extirpation of wolves, agriculture
Used to be hunted extensively for fur/sport
One of main vectors for rabies
- Mainly nocturnal/crepuscular
- Feeds on small rodents, rabbits, birds, insects, fruit, berries
- Will raid garbages and feed on carrion
- Hearing sensitive to low-frequency rustling/gnawing sounds from prey
- Hunts by stalking close, leaping up and landing on and pinning prey w/ forefeet
- Adults form long-term pair bonds
- Usually seen alone since they forage alone
- Territory 0.6-6 km^2
- Young born in underground dens w/ multiple entrances
- Young males disperse widely but females may stay for some time with parents
- Favours mixed habitat w/ brushland & fields


Identification of Vulpes vulpes (skull)

- Temporal ridges form V shape
- Lower part of mandible not notched at posterior end


Identification of Vulpes vulpes (skin)

- Back usually reddish, but occasionally brownish or black
- Feet black
- Bushy tail tipped with white (all colour phases)
- Long legs
- "Silver phase" blackish with various amounts of silvery frosting
- "Cross phase" grey or orange-brown with dark cross on shoulders
- Alternate phases mainly in Canada/Alaska


Identification of Felidae (skull)

- Three or four upper cheek teeth
- Posterior upper cheek tooth very small; long axis perpendicular to long axis of adjacent tooth
- Three lower cheek teeth; all blade-like
- Short rostrum


Identification of Felidae (skin)

- Body cat-like
- Claws curved, sharp and retractile
- Lacks scent gland at dorsal base of tail
- Tail short & not bushy


Lynx canadensis

Canada lynx
Fairly common in northern regions, southern range reduced due to overexploitation
- Most active at dawn/dusk
- Hunts by stalking close and bouncing onto prey in 1-2 bounds
- Feeds mainly on snowshoe hares
- Populations follow a cyclical pattern with highs every 10 years
- Mainly solitary
- Lives mainly in coniferous forests
- Favours areas of dense vegetation, swamps, and rocks


Identification of Lynx canadensis (skull)

- Max. width of presphenoid 6mm or more
- Crest on occipital bone extends more than 3mm posterior to foramen magnum
- Posterior edge of palate rounded


Identification of Lynx canadensis (skin)

- Ears have tuft of black hairs
- Black marking at tip of tail continuous around tail
- Hind foot length greater than 200mm
- Fur on back is greyish and not spotted


Lynx rufus

Common in south & west range; largely extirpated in midwest
- Mainly nocturnal, but can be active at any time of day
- Swims well
- Will climb trees to avoid predators
- Travels and hunts on the ground
- Eats mainly rabbits and rodents, but will prey on other things
- Sneaks up on prey then pounces and strikes
- Mainly solitary
- Highly variable habitats


Identification of Lynx rufus (skull)

- Max. width of presphenoid <6mm
- Crest on occipital bone less than 3mm posterior to foramen magnum in ventral view
- Posterior edge of palate squared


Identification of Lynx rufus (skin)

- Ear tufts absent or small
- Only dorsal surface of tail with black mark
- Hind foot <200mm


Mephitis mephitis

Striped skunk
Common to abundant
- Mainly nocturnal
- Rummages through leaf litter for food
- Growls, purrs, hisses in warning
- Stamps feet before spraying
- Eats mainly insects; also small mammals, birds, bird eggs, fruit, carrion, plant material
- Usually solitary; but may share winter dens or congregate at feeding areas
- Fattens up in the fall and spends a lot of winter in den
- Does not hibernate
- Usually not far from water


Identification of Mephitis mephitis (skull)

- Posterior border of palate ~even with posterior border of last upper tooth
- Anterior border of last upper tooth straight, not indented
- Four upper cheek teeth


Identification of Mephitis mephitis (skin)

- Front claws not greatly enlarged compared to rear claws
- Max. 2 broad white stripes on back
- Top of head & neck white
- Black with white stripe


Identification of Mustelidae (skull)

- Four or five upper cheek teeth
- Posterior upper cheek tooth not small next to adjacent tooth
- Five or more lower cheek teeth; not all blade-like


Identification of Mustelidae (skin)

- Rings absent on tail
- No black facial mask
- Colour never uniform black above and below
- Obvious tail with variable length


Lontra canadensis

Northern river otter
Extirpated from much of former US range
Suffers from water pollution & habitat loss
Has been protected and reintroduced successfully in 7 US states & Alberta
- Semiaquatic; strong swimmer
- Swims with head exposed and body underwater
- Mainly crepuscular, but can be active at all times of day
- May travel long distances on land when dispersing or in search of open water
- Mainly eats fish, frogs, crayfish, molluscs
- Dens in bank burrows, under roots/brush; entrances either above or below water
- Males usually solitary; may form bachelor groups
- Groups usually consist of female and young
- Mating takes place soon after young are born; implantation delayed 8-9 months
- Lives in all water areas


Identification of Lontra canadensis (skull)

- Five lower cheek teeth
- Five upper cheek teeth
- Large infraorbital foramen; ~8mm L ~5mm W


Identification of Lontra canadensis (skin)

- Feet fully webbed
- Tail unusually thick and muscular at base; strongly tapered towards tip
- Total length >700mm
- Short legged
- Upper parts dark brown, underside silvery


Martes americana

American marten
- Active all day
- Seldom seen
- Agile & semiarboreal
- Swims well
- Usually hunts on the ground
- May travel under snow in winter
- Diet varies depending on food availability and season
- Sleeps on branches or in hollow logs
- May den under snow in winter
- Does not hibernate
- Lives in mature coniferous or mixed forests


Identification of Martes americana (skull)

- Five upper cheek teeth
- Six lower cheek teeth
- No exposed rootlet on outer side of fourth upper cheek tooth
- Greatest length of skull 95 mm or less
- Infraorbital foramen small to medium (less than 6mm L x 4mm W)


Identification of Martes americana (skin)

- Body yellowish brown to dark brown
- Head paler than back
- Chin brown
- Legs/feet/tail darker than back
- Large orange/buff/cream patch covering throat and extending onto chest
- Feet relatively large
- Total length 660mm or less
- Ears more than 25mm in height
- Ears have light-coloured border


Identification of Martes pennanti (skin)

- Large, bushy-tailed
- Body dark brown to black
- Long guard hairs
- Head/neck/shoulders grizzled yellow-brown or greyish-yellow
- Legs/feet/tail blackish
- No large buff/cream patch but small patches may occur on throat/chest
- Total length usually much greater than 660mm
- Ears more than 25mm high w/ light-coloured border


Mustela erminea

Widespread & common
- Active for short periods, followed by 3-5 hour rest periods throughout day
- Flat-backed trot to arch-backed gallop
- Investigates surroundings busily, stops periodically to stand up and survey area
- Swims well
- Can climb high into trees
- Eats small rodents, rabbits, shrews, insects, etc.
- Sometimes takes prey larger than itself
- Dens in burrows of other small mammals
- Active year-round
- Travels under snow via rodent tunnels in winter
- Mates in spring; embryonic development deayed 9 months
- Lives in mainly coniferous forest or mixed forests; brushy fields, tundra, etc.


Identification of Mustela erminea (skull)

- Postorbital process blunt and weakly developed
- Greatest width of skull <24mm
- Greatest length of skull 35mm - 55mm
- Posterior border of palate well behind last upper tooth
- Hourglass-shaped chewing surface on last upper cheek tooth


Identification of Mustela erminea (skin)

- Tail length <450mm


Mustela frenata

Long-tailed weasel
Widespread but uncommon/rare
- Active day or night
- Gallops with back arched and tail held up
- Hunts for prey on ground, in trees, and in underground burrows
- Swims well
- Feeds on small to medium mammals, birds (eggs), snakes, insects, carrion
- Breeding in summer with young born following spring
- Lives in forests, meadows, fields
- Favours open areas w/ dense vegetation, near water


Identification of Mustela frenata (skull)

- Postorbital process pointed
- Greatest width of skull >20mm F; >24mm M- Greatest length of skull 35 - 55 mm
- Posterior border of palate well behind last upper tooth
- Hourglass-shaped chewing surface on last upper cheek tooth


Identification of Mustela frenata (skin)

- Largest weasel in North America
- Tail length >44% heady+body length
- Colour highly variable overall
- Summer: brown above
- Winter: white to yellowish (north only)
- Terminal portion of tail black
- Ventral fur mostly white to yellowish-white


Mustela nivalis

Least weasel
Uncommon-rare, can be locally abundant
- Alternates periods of activity and rest throughout the day and night
- When awake, frantically darts in and out of runways & burrows, pausing momentarily to stand up and look around
- Feeds on voles and mice; also birds & eggs, insects, shrews, moles
- Narrow body allows it to pursue prey in small burrows
- Eats almost half its weight daily
- Caches extra prey in chambers and burrows
- Male home ranges include the ranges of several females
- Strong-smelling musk used to mark territory
- Lives in open areas


Identification of Mustela nivalis (skull)

- Greatest length of skull 35mm or less
- Basically, really small
- Posterior border of palate well behind last upper tooth
- Hourglass-shaped chewing surface on last upper cheek tooth


Identification of Mustela nivalis (skin)

- Small
- Terminal portion of tail not obviously black
- Summer: back brown; forefeet often white (sometimes brown); hind feet often brown (sometimes white)
- Winter: entirely white or off-white
- Ventral fur mostly white or yellowish white


Neovison vison

American mink
Widespread, common in suitable areas
- Mainly nocturnal/crepuscular
- Excellent swimmers
- Mainly aquatic prey summer, terrestrial winter
- Eats small to medium mammals, crayfish, frogs, snakes, birds
- Dens near water in tree roots, muskrat houses, burrows in banks
- May use several different dens
- Males occupy larger range than females
- Lives in wooded areas along bodies of water


Identification of Neovison vison (skull)

- Greatest length of skull >55mm
- Posterior border of palate well behind last upper tooth
- Hourglass-shaped chewing surface on last upper cheek tooth


Identification of Neovison vison (skin)

- Feet partly webbed, but doesn't look like an otter
- No light-coloured border on ears


Taxidea taxus

American badger
Locally common to rare
Endangered in Ontario
- Mainly nocturnal
- Good digger
- Uses burrows for resting, raising young, food storage
- Digs up & feeds on rodents; also invertebrates, snakes, carrion
- May stay in burrow during bad weather
- Will become torpid but never hibernates
- Solitary except when breeding
- Males hold large territories, may mate with multiple females
- Mate in summer-fall; implantation delayed until spring


Identification of Taxidea taxus (skull)

- Last upper cheek tooth triangular in outline
- Skull roughly triangular in outline when viewed dorsally
- Large


Identification of Taxidea taxus (skin)

- Front claws massive
- Single white stripe down midline from snout to shoulders
- White face with black markings


Procyon lotor

Northern raccoon
Hunted in some areas for sport
Can carry rabies and other parasites
- Mainly nocturnal
- Moves with bouncing gait; back arched and head low
- Sleeps by day on branch or in tree hollow; sometimes burrow/building
- Eats a wide variety of food
- May dabble in water for prey
- Manipulates items with front paws
- May stay in den for several days during bad weather; never hibernates
- Usually solitary but groups may share den
- Young stay with mom for 6-9 months
- Adult females remain in same area, males travel in search of mates


Identification of Procyon lotor (skull)

- Posterior border of palate well behind last upper tooth
- Six lower cheek teeth


Identification of Procyon lotor (skin)

- Tail has multiple dark rings
- Black facial mask


Ursus americanus

Black bear
Range very reduced in east
Often hunted, but are shy and are seldom dangerous
- Usually active by day in wild areas; may be nocturnal near human populations
- Walk with shuffling gait; can gallop quickly
- Climb well
- Eat mainly nuts, berries, and vegetation; also insects, birds eggs, young mammals, carrion
- Mostly solitary; may form social hierarchy at rich feeding area
- Male occupies large range that encompasses ranges of many females
- Dormant for up to 7 months in northern part of range
- Lives in forests and swamps in east
- Lives in mountains, tundra, rainforest west


Identification of Ursus americanus (skull)

- Last upper cheek tooth 1.5x long as wide
- Long axis of last upper cheek tooth parallels long axis of skull
- Skull massive


Identification of Ursus americanus (skin)

- Body massive and not elongate
- Uniform black colour both above and below; various colour forms may arise
- Always buff brown muzzle
- Possible white throat patch
- Total length much greater than 800mm
- Tail inconspicuous


Martes pennanti

Numbers reduced, recovering in suitable habitat

- Active day or night
- Climbs well but usually hunts terrestrially
- Eats a variety of small mammals; especially snowshoe hare
- One of the few predators of adult porcupines
- Does not hibernate
- Breeding takes place soon after litter born
- Implantation of embryo postponed ~11 months


Identfication of Martes pennanti (skull)

- Exposed rootlet present on outer side of upper carnassial
- Greatest length of skull >95mm
- Six lower cheek teeth



Order within Ferae
Ethiopian & Oriental regions


Identification of Pholidota

- Edentulate
- Cranium robust, conical
- Incomplete zygomatic arch
- Mandible slender, lacks angular and coronoid processes
- Mandible has small, laterally directed prongs near the anterior end
- Tongue long, vermiform; originates on xiphoid process of sternum
- Mostly covered by large, overlapping, keratinous scales (none on underside)
- Scale-less spot ventrally on tail tip in arboreal forms
- Plantigrade
- Pes pentadactyl; manus functionally tridactyl
- Large recurved claws on both manus & pes
- Tail semi-prehensile in two arboreal species
- Can be distinguished from echidnas by lack of elevated braincase, robustness, lack of angular & coronoid
- Can be distinguished from Vermilingua by lack of lacrimal bones, robustness, lack of angular & coronoid



Limb structure in which the large central (third) digit carries most of the weight of the animal
- Smaller lateral digits may or may not be present



Order within Euungulata
Horses, rhinos, tapirs
Ethopian, Oriental, Neotropical regions


Identification of Perissodactyla

- Limbs unguligrade & mesaxonic
- Skulls tend to be elongated
- Canines, where present, are small
- Molars and most premolars have complex pattern of lophs & ridges
- Diastema present


Identification of Equidae (Horses)

- Digits on manus & pes number 1
- Dental formula I 3/3 : C 0-1/0-1 : P 3-4/3 : M 3/3 (T: 36-42)
- Cheek teeth hypsodont with complex grinding surface
- Canines, when present, small and located in diastema
- Orbit completely separated from temporal fossa by postorbital plate
- Body fully haired


Identification of Rhinocerotidae

- Digits on manus & pes number 3
- Dental formula I 0-2/0-1 : C 0-1/0-1 : P 3-4/3-4 : M 3/3 (T: 24-34)
- Cheek teeth lophodont
- Orbit and temporal fossa confluent
- One or two horns made from a solid mass of epidermal cells situated on fused nasal bones
- Body covered with thick skin
- Sparsely haired in most species (except Sumatran rhinoceros)


Identification of Tapiridae

- Digits on manus number 4, pes number 3
- Dental formula I 3/3 : C 1/1 : P 4/3-4 : M 3/3 (T:42-44)
- All four premolars have deciduous precursors
- Brachyodont cheek teeth with transverse ridges
- Confluent orbit and temporal fossa
- Upper lip & nose elongated to form short proboscis
- Short, sleek hair in 3/4 species; soft and wooly in mountain tapir



Group within Laurasiatheria, contains:
- Perissodactyla
- Cetartiodactyla



Order within Euungulata, contains
- Tylopoda
- Suina
- Ruminantia
- Hippopotamidae
- Cetacea
Camels, pigs, ruminants, hippos, whales
"Even-toed ungulates"



Group within Cetartiodactyla that includes:
- Tylopoda
- Suina
- Ruminantia
In all regions, barely Australian


Identification of Artiodactyls

- Third and fourth digits equal in size
- First digit absent, second and fifth are reduced to absent
- Metapodials of third and fourth digits large, fused to form cannon bone in many families
- Digits terminate in pointed hooves, except in Tylopoda
- Astragalus has double-pulley/double-trochlear arrangement that restricts lateral movement



Suborder within Cetartiodactyla
Camels, llamas, etc.
Neotropical, Oriental


Identification of Tylopoda

- Only lateral upper incisor present; it is caniniform
- Lower canines retained
- Lower incisors inclined forward to occlude with hardened section of gums on premaxillae
- Diastema present
- Cannon bone retains separation at distal ends of metapodials, flaring outward
- Each toe is separated and is supported by a broad cutaneous pad; greatly increases surface area of foot
- Short phalanges have nails on dorsal side



Suborder within Cetartiodactyla
Pigs, boars, etc.
Ethopian, Oriental, Palearctic, Neotropical, Nearctic


Identification of Suina

- Skull long and low
- Usually has high occipital area
- Paroccipital process large (Suidae), small (Tayassuidae)
- Canines large, evergrowing
- Upper canines form tusks that protrude from the lips
- Limbs usually short
- May or may not have partial cannon bone



Suborder within Cetartiodactyla
Giraffes, deer, antelope, sheep, goats, cattle



First chamber of stomach
- Sac-like
- Holds food until large particles are forced back to mouth, where they are re-chewed
- Finer particles move further



Second chamber of stomach



Third chamber of stomach
- Food forced further by contraction



Fourth chamber of stomach
- Glandular
- Similar to true stomach of other mammals


Identification of Ruminantia

- Selenodont molars
- Upper incisors absent or reduced
- Lower canine incisiform
- Upper canine mostly absent; long in some
- Head ornamentation present in many
- Trend toward elongation of distal limbs
- Toe main toes on forefoot and hind foot, with lateral digits reduced/absent
- Navicular and cuboid are fused



Present in deer
- Occur in males and both sexes of reindeer and caribou
- Entirely bony structures that are branched older adults
- Shed periodically
- Bone covered in skin (velvet) while growing; shed when bone fully ossified
- Forms from pedicel
- Usually consists of main stem with variable number of tines



Extension of the frontal bone from which antlers grow



Variable number of branches from the main stem of an antler
- Number increases with age until maximum is reached



Present in bovids and pronghorns
- Bony core formed from an extension of the frontal bone
- Outer layer of true horn formed by keratinized epidermis
- Unbranched and permanent in bovids, occurring either in males or both
- Horny sheath shed annually in pronghorns and is branched


"Horns" of giraffes, okapis

- Pair of short, unbranched, permanent bony processes
- Situated over suture between frontal and parietal bones
- Permanently covered by skin & hair
- Ossify and fuse to skull



Family within Cetartiodactyla
Ethopian region, somewhat Palearctic


Identification of Hippopotamidae

- Elevated orbit
- Elongated, tusk-like canine and incisors
- Bunodont molars, basically four-cusped
- Limbs robust, feet have four toes
- Graviportal foot posture



Group within Cetartiodactyla, contains:
- Mysticeti
- Odontoceti
Whales & Dolphins


Identification of Cetacea

- Fully aquatic
- Fusiform bodies
- Large horizontal fluke on tail
- Dorsal fin present in almost all species
- Posterior limbs absent externally
- Only manus is exposed on forelimb; forms a flipper
- Phalanges of at least digits 2/3 exceed usual mammalian number of 3
- Nostrils located high on dorsal surface of head
- External nares located on proximal end of the rostrum
- Short neck, very inflexible; cervical vertebrae may be fused
- Skin essentially hairless
- Thick layer of blubber



Group within Cetacea
Baleen whales


Identification of Mysticeti

- Lack teeth in both jaws
- 130-400 baleen plates suspended from each side of the upper jaw
- Baleen plate is longitudinal strands of horny epithelial material, fringe of tougher strands on lingual edge where matrix is worn away
- Fringe of adjacent plates overlap to produce strainer-like network
- Fringes strain small organisms from water, which are then swallowed
- Skull bilaterally symmetrical
- Nasal bones extend anteriorly over nasal passage
- Nasal passages exit as two separate blowholes



Group within Cetacea
Toothed whales


Identification of Odontoceti

- Teeth almost always present
- Teeth single-rooted, unicuspid, usually conical, homodont
- Baleen always absent
- Skull often bilaterally asymmetrical near external nares
- Nasal bones do not project anteriorly over nasal passage
- Nostrils united into single blowhole



Family within Ruminantia
2 Ontario Species


Alces alces

Locally common
- Mostly active at night
- Often encountered in or near water
- Feeds on leaves, twigs (esp. willows, aspens) and aquatic plants
- Generally solitary
- Several may gather at good feeding areas
- Males fight for females in fall but do not retain a harem
- Females give birth every other year to 1-2 offspring
- Lives in tundra, willow thickets, swamps and northern forests


Identification of Alces alces (skull)

- Antlers very large, widely spread, and palmate where present
- Nasal bones short; do not extend forward of most anterior upper cheek tooth


Identification of Alces alces (skin)

- Largest deer in North America
- Bulbous nose overhangs mouth
- Long bell or dewlap on chin
- Shoulder higher than rump
- Head and body mainly blackish
- Long legs whitish
- Young orange-brown, not spotted


Odocoileus virginianus

White-tailed deer
Generally common & abundant
Thrives in suburban and agricultural areas
- Mainly nocturnal, crepuscular
- Makes beds in grass, leaves, snow
- When encountered, snorts and raises its white tail, bounds off
- Feeds on leaves, twigs, nuts, berries, fungi; may also graze on grass/crops
- Seen in groups of females and young or bachelor males
- Groups of up to 150 may join up in winter in "deer yards"
- Require conifer standings for overwintering in the north
- Groups maintain fixed home but are not territorial
- During breeding season, males rub forehead and antlers on saplings and mark with urine; visited by buck and does
- Variable habitat, needs woodland for cover and open areas for foraging


Identification of Odocoileus virginianus (skull)

- Antlers not flattened
- Antlers consist of one main beam with several vertically directed tines
- Nasal bones long; extend forward of most anterior upper cheek tooth


Identification of Odocoileus virginianus (skin)

- Highly variable in size
- Coat grayish in winter, reddish brown in summer
- Underside white
- Edge of rump and underside of tail white
- Fawns are reddish brown with white spots that fade after 3-4 months