Lab Quiz 1 Flashcards

Question

Presphenoid

Answer 1

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

Answer 2

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

Answer 3

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

Answer 4

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

Answer 5

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

Answer 6

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

Answer 7

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

Answer 8

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

Answer 9

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

Answer 10

``` 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

Answer 11

- Incus - Malleus - Stapes

Answer 12

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

Answer 13

Horizontal portion of each dentary that normally bears teeth

Answer 14

Vertically projecting portion of the dentary

Answer 15

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

Answer 16

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

Answer 17

Ventral to the mandibular condyle | Protrudes posteriorly

Answer 18

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

Answer 19

- Presence of deciduous teeth means they are definitely immature - As an individual gets older the degree of fusion between cranial sutures increases

Answer 20

Portion of a tooth that is exposed above the gumline

Answer 21

Portion of a tooth that fits into the alveolus

Answer 22

Portion of the jaw that contains the tooth sockets

Answer 23

Teeth with particularly high crowns

Answer 24

Teeth with especially low crowns

Answer 25

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

Answer 26

Bonelike material that makes up the major portion of each tooth

Answer 27

Hard material that covers the dentine of the crown

Answer 28

Bonelike material that covers the dentine of the root

Answer 29

Central, living portion of a growing tooth

Answer 30

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

Answer 31

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

Answer 32

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

Answer 33

Having only two sets of teeth: deciduous and permanent

Answer 34

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

Answer 35

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

Answer 36

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

Answer 37

Tooth replacement occurs as the teeth are worn away

Answer 38

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

Answer 39

When all teeth in the jaw have the same basic shape

Answer 40

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

Answer 41

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

Answer 42

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

Answer 43

When the most conspicuous tooth in the anterior part of the jaw is not a canine but rather an incisor that looks like a canine Canine is usually absent or resembles a premolar

Answer 44

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

Answer 45

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

Answer 46

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

Answer 47

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

Answer 48

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

Answer 49

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

Answer 50

Chewing, or processing of the food

Answer 51

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

Answer 52

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

Answer 53

Teeth with four major cusps and a mostly quare crown

Answer 54

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

Answer 55

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

Answer 56

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

Answer 57

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

Answer 58

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

Answer 59

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

Answer 60

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

Answer 61

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

Answer 62

Bunodont cheek teeth

Answer 63

Hypsodont, lophodont, selenodont, or selenolophodont teeth

Answer 64

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

Answer 65

Secodont teeth | Carnassials in Carnivora

Answer 66

Cheek teeth are reduced to a series of sharp unicuspid teeth

Answer 67

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

Answer 68

When an organism lacks teeth entirely

Answer 69

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

Answer 70

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

Answer 71

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

Answer 72

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

Answer 73

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

Answer 74

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

Answer 75

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

Answer 76

Generally rudimentary or absent in mammals Big exception: armadillos

Answer 77

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

Answer 78

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

Answer 79

First cervical vertebra

Answer 80

Second cervical vertabra

Answer 81

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

Answer 82

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

Answer 83

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

Answer 84

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

Answer 85

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

Answer 86

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

Answer 87

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

Answer 88

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

Answer 89

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)

Answer 90

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

Answer 91

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

Answer 92

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

Answer 93

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

Answer 94

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

Answer 95

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

Answer 96

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

Answer 97

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

Answer 98

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

Answer 99

Hand or forefoot

Answer 100

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

Answer 101

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

Answer 102

Elongate bones, one for each digit Enclosed within the forefoot

Answer 103

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

Answer 104

Most medial digit on the forefoot Has only two phalanges

Answer 105

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

Answer 106

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

Answer 107

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

Answer 108

Proximal element of the pelvic limb

Answer 109

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

Answer 110

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

Answer 111

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

Answer 112

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

Answer 113

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

Answer 114

Large tarsal bone adjacent and medial to the calcaneum

Answer 115

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

Answer 116

Most medial digit on the foot Consists of two phalanges

Answer 117

Hind foot, including the tarsals, metatarsals and phalanges

Answer 118

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

Answer 119

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

Answer 120

Ventral plate on a claw/nail

Answer 121

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

Answer 122

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

Answer 123

Walking! 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

Answer 124

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

Answer 125

Running! Adaptations: - Digitigrade or unguligrade - Increase in limb length increases stride length

Answer 126

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

Answer 127

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

Answer 128

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

Answer 129

Leap in which all four feet are involved

Answer 130

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

Answer 131

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

Answer 132

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

Answer 133

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 ```

Answer 134

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

Answer 135

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

Answer 136

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

Answer 137

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

Answer 138

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

Answer 139

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

Answer 140

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

Answer 141

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

Answer 142

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

Answer 143

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

Answer 144

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