Class Mammalia

Question 1

e.g. platypus, echidna
(6 species)
Ecology: aquatic, ground-dwelling, or fossorial
Characteristics: The only egg-laying mammals, monotremes differ from other mammals in several ways. They display no teeth as adults and have specialized electrosensory receptors in the beaks/bills that help them detect prey. Platypuses are aquatic, and males have a venom gland connected to a spur on their hind leg which they use when fighting rivals or predators. Echidnas are ground-dwelling or burrowing and largely feed on ants and termites.

Answer 1

Subclass: Prototheria
Infraorder: Ornithodelphia
Order: Monotremata

Question 2

e.g. kangaroos, wallabies, koala, wombats, opossums, Tasmanian tiger, Tasmanian devil, marsupial mice, cuscuses, bandicoots, bilbies
(331 species)
Ecology: Cosmopolitan
Characteristics: Give birth to small, altricial young that develop in the marsupium (pouch). Some kangaroos can undergo embryonic diapause to delay development of an embryo until environmental conditions become favorable.

Answer 2

Subclass: Theria
Infraclass: Metatheria

Question 3

e.g. opossum

Answer 3

Subclass: Theria
Infraclass: Metatheria
Order: Didelphimorpha

Question 4

e.g. kangaroo, koala, wombats, wallabies, possums

Answer 4

Subclass: Theria
Infraclass: Metatheria
Order: Diprotodontia

Question 5

e.g. two-toed sloth, giant anteater, armadillo
(31 species)
Ecology: Arboreal or cursorial; largely in tropical or desert areas
Characteristics: much more diverse in the past, and included giant armadillo-like Glyptodonts, which got as large as a large SUV

Answer 5

Subclass: Theria
Infraclass: Eutheria
Order: Xenarthra

Question 6

e.g. pika, brush rabbit
(91 species)
Ecology: Saltatory, in a wide range of habitats
Characteristics: Although originally grouped in with the rodents, they are distinct in having two pairs of upper incisors, one pair being located directly posterior to the other pair

Answer 6

Subclass: Theria
Infraclass: Eutheria
Order: Lagomorpha

Question 7

e.g. fox squirrel, yellow-bellied marmot, flying squirrel, agile kangaroo rat, bushy-tailed woodrat, deer mouse, pocket gopher, porcupine, Norwegian rat
(2277 species)
Ecology: cursorial, arboreal, fossorial, semi-aquatic, in a wide range of habitats
Characteristics: The most speciose mammalian group, they have extremely sharp teeth and strong jaw muscles for chewing, gnawing, and chiseling a wide variety of tough foods (nuts, grains, acorns, seeds, woody plants)

Answer 7

Subclass: Theria
Infraclass: Eutheria
Order: Rodentia

Question 8

e.g. saddleback tamarin, cinnamon monkey, baboon, human
(376 species)
Ecology: arboreal, ground-dwelling
Characteristics: Most are omnivorous, but some specialize in eating tree sap or tree-burrowing insects

Answer 8

Subclass: Theria
Infraclass: Eutheria
Order: Primates

Question 9

e.g. broad-footed mole, shrew
(542 species)
Ecology: Generally ground-dwelling and burrowing, sometimes arboreal. Some semi-aquatic species (water shrews)
Characteristics: Generally small, eating a variety of invertebrate prey

Answer 9

Subclass: Theria
Infraclass: Eutheria
Order: Liptophyla

Question 10

e.g. pallid bat, big brown bat, flying fox
(1120 species)
Ecology: Aerial, largely nocturnal
Characteristics: Lateral skin of bodies and limbs developed into a web of skin, called the patagium, that connects their finger bones and has allowed them to evolve flapping flight like the birds. Many are able to navigate in complete darkness using echolocation. This order includes the smallest known mammal, the bumblebee bat, which weights less than a penny

Answer 10

Subclass: Theria
Infraclass: Eutheria
Order: Chiroptera

Question 11

e.g. racoon, black bear, red fox, bobcat, hyena, striped skunk, sea otter, sea lion, seal
(286 species)
Ecology: extremely varied: cursorial, arboreal, aquatic
Characteristics: Although secondarily lost or modified for omnivory in some species, all have a set of cutting teeth, the carnassials, formed by the upper premolar 4 and lower molar 1

Answer 11

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora

Question 12

e.g. racoon

Answer 12

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Procyonidae

Question 13

e.g. black bear

Answer 13

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Ursidae

Question 14

e.g. red fox, coyote, domestic dog

Answer 14

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Canidae

Question 15

e.g. bobcat, domestic cat, lion

Answer 15

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Felidae

Question 16

e.g. spotted hyena

Answer 16

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Hyenidae

Question 17

e.g. striped skunk

Answer 17

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Mephitidae

Question 18

e.g. sea otter

Answer 18

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Mustelidae

Question 19

e.g. sea lion

Answer 19

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Otariidae

Question 20

e.g. harbor seal, elephant seal

Answer 20

Subclass: Theria
Infraclass: Eutheria
Order: Carnivora
Family: Phocidae

Question 21

e.g. pig, peccary, cow, goat, sheep, pronghorned antelope, mule deer
(241 species)
Ecology: Cursorial
Characteristics: They have an even number of digits on each foot. Specie may have antlers or horns. Horns are found in the Family Bovidae, while antlers are usually found in the Family Cervidae. True horns are not shed and may be present in both sees. The number of points on a set of antlers is a reflection of age, hormones, and nutrition.

Answer 21

Subclass: Theria
Infraclass: Eutheria
Order: Artiodactyla

Question 22

e.g. pig, wild boar

Answer 22

Subclass: Theria
Infraclass: Eutheria
Order: Artiodactyla
Family: Suidae

Question 23

e.g. peccary

Answer 23

Subclass: Theria
Infraclass: Eutheria
Order: Artiodactyla
Family: Tayassuidae

Question 24

e.g. cow, domestic goat, bighorn sheep

Answer 24

Subclass: Theria
Infraclass: Eutheria
Order: Artiodactyla
Family: Bovidae

Question 25

e.g. pronghorn antelope

Answer 25

Subclass: Theria
Infraclass: Eutheria
Order: Artiodactyla
Family: Antilocapridae

Question 26

e.g. mule deer

Answer 26

Subclass: Theria
Infraclass: Eutheria
Order: Artiodactyla
Family: Cervidae

Question 27

e.g. humpback whale, blue whale, bottlenose dolphin, sperm whale, orca
(82 species)
Ecology: Fully aquatic
Characteristics: Well adapted for living in the water, and have thick blubber for insulation to help with thermoregulation.

Answer 27

Subclass: Theria
Infraclass: Eutheria
Order: Cetacea

Question 28

e.g. humpback whale, blue whale (baleen whales)

Answer 28

Subclass: Theria
Infraclass: Eutheria
Order: Cetacea
Suborder: Myticeti

Question 29

e.g. bottlenose dolphin, sperm whale, orca (toothed whales)

Answer 29

Subclass: Theria
Infraclass: Eutheria
Order: Cetacea
Suborder: Odontoceti

Question 30

e.g. domestic horse
(17 species)
Ecology: Cursorial
Characteristics: They are known as the odd-toed ungulates, and include zebras, tapirs, donkeys, and rhinoceroses. Extant species within the order may have 1 or 3 toes per foot, although this generalization does not hold true for the fossil record.

Answer 30

Subclass: Theria
Infraclass: Eutheria
Order: Perissodactyla

Question 31

e.g. African elephant
(3 species)
Ecology: Cursorial
Characteristics: The total number of teeth is 24 (6 in each half jaw). No more than two of the six teeth are exposed at the same time in each side of the jaw (the only exception is in young elephants which may use 3). Teeth grow from the back of the jaw and follow a linear pathway of movement forwards as the preceding tooth is progressively worn down in the front. Each tooth drops out as it reaches the front of the elephant’s jaw. The tusks are modified upper incisors, not canines.

Answer 31

Subclass: Theria
Infraclass: Eutheria
Order: Proboscidea