Mammalian Taxonomy and Biology Lecture Notes

Comprehensive vocabulary flashcards covering the diagnostic traits, diversity, and classifications of mammalian orders and families based on the lecture notes.

Amniotic egg

An egg structure consisting of an embryo surrounded by an amnion, allantois, chorion, yolk sac, and an outer leathery skin.

Mammalia (Diagnostic Skull Characteristics)

A unique skull design characterized by a single dentary bone, three ossicles of the middle ear, and two occipital condyles.

Order Monotremata

An order of 5 oviparous species (echidnas and duck-billed platypus) endemic to the Australian region; characterized by a cloaca, epipubic bone, no external pinnae, lack of adult teeth, mammary glands without nipples, and a venomous hind-foot spine in males.

Order Didelphimorphia

The most generalized marsupials (127 species) of the Neotropical and Nearctic regions, possessing the primitive marsupial count of 50 teeth, an opposable clawless hallux, and often a long prehensile tail.

Family Didelphidae

Opossums possessing small incisors, a long rostrum, a narrow braincase, a prominent sagittal crest, an opposable first digit on the hind foot, a naked scaly prehensile tail, and a marsupium.

Order Paucituberculata

Shrew or rat opossums (7 species) that resemble shrews with elongate heads, reduced eyes, unspecialized feet, long non-prehensile tails, and no marsupium.

Order Microbiotheria

An order of 3 species, including Dromiciops gliroides (Monito del monte), found in forested areas of the Andes Mountains (Neotropical region); features 50 teeth, a marsupium, and a moderately prehensile tail that accumulates fat for hibernation.

Order Dasyuromorphia

An Australian marsupial order (88 species) including marsupial mice, marsupial cats, Tasmanian wolf, Tasmanian devil, and numbat; characterized by 42 to 46 teeth, plantigrade to cursorial digitigrade locomotion, a furred non-prehensile tail, and an often absent marsupium.

Order Peramelemorphia

Bandicoots and bilbies (30 species) of the Australian region, featuring an elongate pointed snout, 46 to 48 teeth, hind limbs longer than forelimbs, and a rearward-opening marsupium.

Order Notoryctemorphia

Fossorial marsupial moles (2 species) restricted to Australia; characterized by skin-covered nonfunctional vestigial eyes, reduced pinnae, enlarged claws, and a marsupium partly divided into two areas.

Order Diprotodontia

A diverse Australian order of 158 species including kangaroos, wallabies, wombats, and koalas, displaying a wide array of shapes, sizes, and dietary adaptations.

Order Afrosoricida

Tenrecs and golden moles (55 species) native to the Ethiopian region; characterized by reduced pinnae, small weak eyes, no auditory bullae, non-scrotal testes, a baculum in some, and venomous saliva in two genera.

Order Eulipotyphla

An order of 557 species worldwide (except Australia and southern Neotropical regions) including moles, shrews, and solenodons; features heterodont teeth with large incisors, no auditory bullae, non-scrotal testes, and venomous saliva in two genera.

Family Talpidae

Moles adapted for burrowing, featuring broadened front digging feet, thick soft velvety fur, small eyes, head and forelimbs modified for burrowing, and ears that usually lack external pinnae.

Family Soricidae

Shrews characterized by elongated upper middle incisors and long thin snouts for prey capture, small external pinnae, and very small eyes; typically live in leaf litter or under logs rather than being truly fossorial.

Order Macroscelidea

Elephant shrews (20 species) of the Ethiopian region; diurnal, terrestrial forms with large eyes and ears, a very long moveable snout, long cursorial limbs, complete auditory bullae, and complete zygomatic arches.

Order Scandentia

Tree shrews (23 species) of the Oriental region resembling squirrels; arboreal and mostly diurnal with large eyes, 5 digits with recurved claws, furred tails, complete auditory bullae, and complete zygomatic arches.

Order Dermoptera

Colugos or flying lemurs (2 species) of the Oriental region; glissant arboreal herbivores with a furred patagium, large eyes, large curved claws, and lower incisors that are widened and pectinate.

Order Chiroptera

The only order of flying (volant) mammals, characterized by wings constructed of hand membranes supported by elongated digits 2 through 5.

Suborder Megachiroptera

Fruit bats (186 species) with large eyes, well-developed vision, and simple ears lacking a tragus; they do not use echolocation and cannot fly in total darkness.

Suborder Microchiroptera

Bats (945 species) with small eyes and ears that typically possess a tragus; use echolocation as the primary mechanism for orientation and prey capture.

Family Desmodontidae

Vampire bats (1 species) characterized by sanguinivorous feeding habits and the ability to walk quadrupedally.

Family Molossidae

Free-tailed bats that are insectivorous and echolocating; known for forming massive colonies ($10^5$ to $10^6$ individuals) in caves across the southwest United States that create extensive guano deposits.

Family Vespertilionidae

The most widespread bat family globally (and most common in Utah and North America); insectivorous and echolocating bats that exhibit variable life histories including colonial or solitary habits and spring or fall mating.

Order Primates

Mammalian order (519 species) characterized by arboreal or terrestrial adaptations, plantigrade feet, nails on digits (some claws), well-developed vision, reduced sense of smell, and relatively large braincases.

Order Carnivora

Mammalian order (309 species) possessing 4 to 5 digits, a baculum, heterodont or homodont dentition (tusks from upper canines in walruses), and diverse terrestrial, arboreal, amphibious, or aquatic adaptations.

Family Felidae

Cats characterized by an extremely shortened rostrum, retractile claws, well-developed carnassials, and a hunting style based on stalking and short sprints.

Family Canidae

The most cursorial of the carnivores (dogs, wolves, foxes, jackals); characterized by long rostra with large nasal chambers, acute sense of smell, non-retractile claws, and opportunistic omnivorous-carnivorous diets.

Family Ursidae

Bears; plantigrade, ambulatory carnivorans with less-developed carnassials and an omnivorous diet, known to undergo winter inactivity rather than true hibernation.

Family Mustelidae

Carnivorans (badgers, weasels, otters, wolverines) that are typically small and short-legged, possessing well-developed anal scent glands and sharp carnassials (except in otters).

Family Otariidae

Eared seals and sea lions; pinnipeds possessing small external ears whose hind flippers can rotate under the body for terrestrial locomotion.

Family Phocidae

Earless seals; pinnipeds lacking external ears whose hind flippers cannot be rotated forward under the body, rendering them useless on land.

Family Odobenidae

Walruses (1 species worldwide); pinnipeds possessing large tusks modified from upper canines that assist in gathering mollusks from the seafloor.

Order Hyracoidea

Hyraxes or dassies (6 species) endemic to the Ethiopian region; characterized by 2 continuously growing upper incisors, 4 chisel-like lower incisors, and soft elastic hooved pads on functional digits.

Order Proboscidea

Elephants (3 species); the largest terrestrial mammals, characterized by graviportal limbs, upper incisors modified into ever-growing tusks, absence of canines and lower incisors, and air cells within the skull bones.

Order Sirenia

Dugongs and manatees (5 species); fully aquatic herbivores found in tropical coastal and riverine waters, characterized by high dorsal nares, paddle-like forelimbs, vestigial pelvic bones, and a horizontal tail fluke.

Order Perissodactyla

Odd-toed ungulates (horses, tapirs, rhinos; 8 species) adapted to unguligrade cursorial locomotion, where body weight is borne entirely on the enlarged middle digit; characterized by a simple stomach and a diastema between front and cheek teeth.

Order Artiodactyla

Even-toed ungulates (pigs, hippos, ruminants, cetaceans; 362 species) where weight is borne equally on the third and fourth digits; capable of rising hindfeet first and possessing simple to complex multi-chambered stomachs.

Family Antilocapridae

Pronghorns (1 species endemic to North America); the fastest North American cursorial mammal, characterized by branched horns with a keratin sheath that is shed annually.

Parvorder Mysticeti

Baleen whales; aquatic mammals with two blowholes (narial openings), keratinous baleen plates instead of teeth, and a planktivorous diet without echolocation capabilities.

Parvorder Odontoceti

Toothed whales (including dolphins and porpoises); cetaceans possessing a single blowhole, true homodont teeth, and active echolocation systems.

Family Balaenopteridae

Rorqual whales (such as blue, humpback, and minke whales), representing the largest animals; can reach up to $140{,}000\,\text{kg}$ and $27\,\text{m}$, feeding on up to $3{,}600\,\text{kg}$ of krill per day using baleen plates.

Order Cingulata

Armadillos (22 species) of the Neotropical and Nearctic regions; lacking incisors and canines, having enamel-free peg-like cheek teeth, and possessing extra xenarthrous articulations on lumbar vertebrae.

Family Dasypodidae

Armadillo family possessing homodont cheek teeth, a horny epidermis overlaying bony plates, and the reproductive hallmark of giving birth to identical quadruplets.

Order Pilosa

Sloths and anteaters (16 species) of the Neotropical region; characterized by xenarthrous lumbar vertebral articulations, lack of incisors and canines, and enamel-free or absent teeth.

Order Pholidota

Pangolins (8 species) of the Oriental and Ethiopian regions; covered in protective keratinous scales, completely lacking adult teeth, and using an elongated protractile tongue and a gizzard-like muscular stomach that grinds food with swallowed pebbles.

Order Tubulidentata

The only monotypic eutherian order, consisting solely of the aardvark (Ethiopian region); characterized by columnar cheek teeth made of dentine tubes surrounding pulp, powerful digging claws, and large burrow systems.

Order Rodentia

The most species-rich mammalian order ($2{,}655$ species across 31 families), characterized by a single pair of upper and lower chisel-like incisors that grow continuously, have enamel only on the front surface, and are separated from cheek teeth by a wide diastema.

Family Aplodontidae

The mountain beaver (1 species); recognized as the most primitive living rodent, herbivorous, building colonial burrows and hay piles along moist stream edges.

Family Geomyidae

Pocket gophers; strictly fossorial rodents with external fur-lined cheek pouches, forward-projecting incisors, and lips that close behind the incisors to exclude soil during digging.

Family Heteromyidae

Kangaroo rats and pocket mice; arid-adapted granivorous rodents possessing external fur-lined cheek pouches, saltatorial or ricochetal bipedal locomotion, long tails, and large hind feet.

Order Lagomorpha

Pikas, rabbits, and hares (108 species); distinguished by four upper incisors (the second upper incisor is a peglike tooth seated directly behind the first) and two lower incisors, fused tibia and fibula, and a wide diastema.

Family Ochotonidae

Pikas; small lagomorphs inhabiting talus slopes in North American mountains, possessing short rounded ears, no visible tail, and the habit of curing vegetation into winter hay piles.

Family Leporidae

Hares and rabbits; cursorial lagomorphs with hindlimbs distinctly longer than forelimbs, relatively long ears, and fully herbivorous diets.