Orders and mammal characteristics Flashcards
(44 cards)
What are the two subclasses of mammalia?
Prototheria (monotremes, lay eggs and poisonous spurs) and theria
Name two infraclasses of mammalia
metatheria (marsupials) and Eutheria (non-marsupials)
About how many mammal species are presumed to be living in the wild?
6,500
Name the 11 unique characteristics of mammals discussed in class
- Hair
- 4-chambered heart
- Enucleate erythrocytes (except camelids)
- Mammary glands
- Muscular diaphragm
- Unique skull
○ Single dentary bone
○ Three oscicles of the middle ear
○ Two occipital condyles (reptiles only have one) - Mammals have epiphyses in their long bones (determinant growth)
○ Reptiles do not (no epiphyses) - Mammals are heterodonts and diphyodont
- Viviparous (except monotremes) - i.e. live birth
- Endotherms
- Large, complex brain
What are the characteristics of order Monotromata?
ORDER MONOTROMATA Echidnas (spiny anteater) and duck-billed platypus -oviparous -cloaca (common tract to digestion, excretion, and reproduction) -no teeth in adults -No external pinnae -Venomous spine on hind foot in males -mammary glands without nipples -Australian region
Characteristics of order Didelphimorphia
ORDER DIDELPHIMORPHIA (127 Species) Opossums Most generalized marsupials Rostrum elongate with small braincase 50 teeth (most primitive number) Opposable and clawless hallux Plantigrade Marsupium is present to absent Tail often long and prehensile Most partly arboreal and omnivorous Neotropical and nearctic regions
Characteristics of order Paucituberculata
Shrew opossums Resemble shrews with elongate heads and reduced eyes Feet unspecialized Tail long but not prehensile No marsupium Carnivorous Neotropical 1 family
Characteristics of order Microbiotheria
ORDER MICROBIOTHERIA (3 species) Monito del monte Short face Thick hairy tail, moderately prehensile 50 teeth Hibernates when cold and limited food Tail accumulates fat for hibernation Marsupium Omnivorous Neotropical region
Order dasyuromorphia
Marsupial mice and cats, Tasmanian wolf, Tasmanian devil, numbat Mostly terrestrial, some arborial Limbs and teeth more advanced than didelphids 42-46 teeth Plantigrade mostly, some digitigrade Tail long and furred but not prehensile Marsupium often absent Carnivorous Australian region 3 families
Order peramelemorphia
Bandicoots Terrestrial and nocturnal Snout is elongate and pointed 46-48 teeth Hind limbs longer than fore limbs Many are cursorial Tail long but not prehensile Marsupium present (opens rearward) Placenta more complex than all other marsupials Primarily insectivorous Australian region 2 families
Order Notoryctemorphia
Marsupial mole Fossorial Eyes vestigal and covered by skin Reduced pinnae Nose covered by hard tissue Enlarged claws Marsupium divided into 2 areas Carnivorous Australian region 1 family
Order diprotodontia
Wombats, possums, wallabies, and kangaroos
Most diverse group of marsupials
Wide array of shapes, sizes, food habits, and movement
Australian region
7 families
Order Macroscelidea
Elephant shrews Terrestrial (mouse to large rat in size) Large eyes and ears Very long snouts (hence the name) Relatively long limbs Specialized for rapid movements relative to Insectivores Complete auditory bullae Complete zygomatic arch Carnivorous Diurnal Complex social system relative to Insectivores Ethiopian region 1 family
Order Afrosoricida
Tenrecs and golden moles
Insectivorous
African region
2 families
Order Tubulidentata
Aardvark
Terrestrial and fossorial
Strong limbs and large claws (digs into ant and termite mounds)
Long, thin snout
Long protractile tongue
Long esternal ears that fold back when digging
No incisors or canines
20 cheek teeth but all remain in gums
Teeth columnar with dentine surrounding pulp
Large burrow systems ((3 men lost in burrow in Zambia, one body found)
Insectivorous
Ethiopian region
1 family
Order Proboscidea
Elephants
Largest terrestrial mammals
Limbs are pillar-like (graviportal limb structure)
Skull large, partly for attachment of muscles that support and control proboscis
Air cells in skull to decrease weight
Upper incisor on each side of jaw modified into tusks
No canines, large molariform teeth; as these wear out, new ones grow at the back of the jaw
Herbivorous
Oriental and Ethiopian region
1 family
Order Sirenia
ORDER SIRENIA (5 species)
Manatees, dugong, sea cow
Aquatic from coastal marine to riverine
Only aquatic herbivore
External nares high on skull
Forelimbs paddlelike with five digits, but digits not externally visible
Hindlimbs absent
Tail ~ externally flattened fluke
Tropical coastal regions, manatees in Florida
2 families
Order Hyracoidea
Hyraxes
Rabbit-like mammal, but structurally unique
2 long upper incisors (continuously growing)
4 chisel-like lower incisors
Hooves with soft elastic pads on each digit
Ethiopian region
1 family
Order Pilosa
American anteaters and sloths No incisors or canines Cheek teeth rudimentary or absent No enamel on teeth Extra articulation on lumbar vertebrae to strengthen lumbar region Herbivorous and insectivorous forms Neotropical and Nearctic regions 3 families
Order Cingulata
Armadillos
No incisors or canines; Cheek teeth rudimentary or absent
No enamel on teeth
Extra articulation on lumbar vertebrae to strengthen lumbar region
Herbivorous and insectivorous forms
Neotropical and Nearctic regions
1 families; 1 in North America
Order scandentia
Tree shrews Arboreal Resemble small, long-nosed squirrels Large eyes 5 digits with strongly curved claws Long furred tail Complete auditory bullae Complete zygomatic arch Omnivorous Diurnal although at least one species is nocturnal Oriental region 1 family
Order Dermoptera
Flying lemurs or colugos Totally arboreal Gliding forms 1-2 kg Large eyes, moderate ears 5 digits with large curved claws Long limbs and tail Furred patagium (membrane) from neck to limbs First two lower incisors widened and pectinate (comb-like) to scrape leaves and fruit Herbivorous Elongated intestine with cecum Nocturnal Oriental region 1 family
Order Primates
Lemurs, monkeys, apes, and man
Usually arboreal, some terrestrial
Plantigrade with 5 digits, some bipedal
Usually nails, some claws
Thumbs and great toes often opposable
Tail long and prehensile in some, absent in others
Braincase relatively large
Sight well-developed
Sense of smell reduced
Mostly herbivorous or omnivorous, some insectivorous
Usually single young, altricial
Baculum in most
Essentially tropical and subtropical in new and old world, although humans cosmopolitan
15 families-1 in North America
Order Rodentia
Rats, mice, squirrels, beaver, porcupine, and others
Most common order of mammals
Terrestrial, amphibious, fossorial, arboreal, saltatorial, gliding
Skull musculature and shape for gnawing
2 upper and 2 lower chisel-like incisors
Incisors grow continuously
Enamel only on front of incisors
Long diastema between incisors and cheek teeth (no canines)
Scrotum posterior to penis
Baculum
Herbivorous, granivorous, omnivorous
Worldwide
31 families
