Mammals Flashcards
2 extant subclasses of Mammalia
Prototheria and Theria
2 infraclasses contained within subclass Theria
Metatheria and Eutheria
two key extinct Mammalian groups
Therapsids and Cynodonts
characters of Therapsids
first group to evolve limbs underneath body
characters of Cynodonts
heterodont teeth and secondary palate, dominant lineage of Therapsids
extinct Mammalian group that gave rise to all extant mammals
Cynodonts
common characters of mammals
integument with hair and mammary glands, three ear bones, heterodont teeth, diphyodont tooth replacement, secondary palate, viviparity (except in Monotremes), negative pressure ventilation
mammalian hair
unique to mammals, consists of hollow cuticle filled with keratin
milk production in Monotremes
secrete milk from mammary patch on belly
3 ear bones in mammals
incus, malleus, and stapes
modifications to the amniotic egg in mammals
amnion stays the same, and chorion, allantois, and yolk sac fuse to form the umbilical cord
reproduction in mammals
internal fertilization via male penis, all have live birth but Monotremes
order within subclass Prototheria containing platypuses and echidnas
order Monotremata
characters of Monotremes
only mammals without mammary glands who lay eggs
infraclass of subclass Theria known as marsupials
infraclass Metatheria
characters of Metatheria
live mostly in Australia, rudimentary placenta, embryo develops in marsupium following birth
infraclass of subclass Theria containing rodents, carnivores, and primates
infraclass Eutheria
general characters of infraclass Eutheria
long gestation period, offspring born relatively precocial, shorter nursing period than other mammals
order within infraclass Eutheria containing rats, mice, and hamsters
order Rodentia
general characters of order Rodentia
large gap between incisors and cheek teeth for gnawing, mostly herbivorous
order within infraclass Eutheria containing bats
order Chiroptera
general characters of Chiropterans
nocturnal or crepuscular, mostly insectivores, many echolocate, only mammals with true flight
differences between Chiropteran flight and Avian flight
Chiropteran wings are homologous to animal hands, can’t soar like birds (can only flap), wing membrane less adjustable than feathers, weight distributed across body –> less stability but more maneuverability
order within infraclass Eutheria containing seals, bears, cats, etc.
order Carnivora
general characters of Carnivores
most diverse range of sizes in Mammalia, many are omnivores/herbivores, teeth evolved for tearing and cutting
superorder within infraclass Eutheria containing horses, pigs, and cetaceans
superorder Ungulata
orders within superorder Ungulata
order Perissodactyla and order Artiodactyla
order within Ungulata containing “odd-toed” mammals
order Perissodactyla
order within Ungulata containing “even-toed” mammals
order Artiodactyla
characters of Perissodactylans
some have one toe, some have three, contains horses, rhinos, and tapirs
characters of Artiodactylans
many have antlers or horns, contains horses, pigs, and cetaceans
“order” of infraclass Eutheria evolved from Ungulata containing whales, dolphins, and orcas
order Cetacea
characters of Cetaceans
can be baleen (made from keratin) or toothed, forelimbs modified into flippers, hindlimbs don’t fully develop
order of infraclass Eutheria containing lemurs, tamarins, baboons, and humans
order Primates
general characters of Primates
mostly arboreal with group living, large brains, great vision, complex social systems, hands and feet specialized for gripping
infraclasses within order Primates
infraclass Strepsirrhini and infraclass Haplorhini
infraclass of order Primates known for being “wet-nosed”
infraclass Strepsirrhini
animals contained within infraclass Strepsirrhini
lemurs!
infraclass of order Primates known as “dry-nosed”
infraclass Haplorhini
different Primates contained within infraclass Haplorhini
“new-world” monkeys, “old-world” monkeys, and apes
characters of “new-world” monkeys
lack opposable thumbs
characters of “old-world” monkeys
long tail, mostly omnivorous, opposable thumbs
characters of apes
no tail, larger and stronger than monkeys, increased sociality, opposable thumbs
estimated time when first humans arose
200,000 years ago
