L37 (Animal Diversity IV: Tetrapods)

amphibians

a member of the clade of tetrapods that includes salamanders, frogs, and caecilians

amniotes

a member of a clade of tetrapods named for a key derived character, the amniotic egg, which contains specialized membranes, including the fluid-filled amnion, that protect the embryo. Amniotes include mammals as well as birds and other reptiles

amniotic egg

an egg that contains specialized membranes that function in protection, nourishment, and gas exchange. The amniotic egg was a major evolutionary innovation, allowing embryos to develop on land in a fluid-filled sac, thus reducing the dependence of tetrapods on water for reproduction

ectothermic

referring to organisms for which external sources provide most of the heat for temperature regulation

endothermic

referring to organisms that are warmed by heat generated by their own metabolism. This heat usually maintains a relatively stable body temperature higher than that of the external environment

reptile

a member of the clade of amniotes that includes tuataras, lizards and snakes, turtles, crocodilians, and birds

birds

nested within reptilian clade, they are a diverse group of vertebrates characterized by feathers, beaks, and wings, have weight-saving modifications and are endothermic

ratites

a member of the group of flightless birds

mammals

a member of the clade Mammalia, amniotes that have hair and mammary glands (glands that produce milk)

monotremes

an egg-laying mammal, such as a platypus or echidna. Like all mammals, monotremes have hair and produce milk, but they lack nipples

marsupials

a mammal, such as a koala, kangaroo, or opossum, whose young complete their embryonic development inside a maternal pouch called the marsupium

placenta

a structure in the uterus of a pregnant eutherian mammal that nourishes the fetus with the maternal blood supply; formed from the uterine lining and embryonic membranes

eutherians

placental mammal; mammal whose young complete their embryonic development within the uterus, joined to the female parent by the placenta

primates

includes lemurs, tarsiers, monkeys, and apes, most hanve hands and feet adapted for grasping, and their digits have flat nails, they have a large brain and short jaws, and eyes that are in the front, also have a flexible thumb

opposable thumb

a thumb that can touch the ventral surface (fingerprint side) of the fingertip of all four fingers of the same hand with its own ventral surface

anthropoids

a member of a primate group made up of the monkeys and the apes (gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans)

paleoanthropology

the study of human origins and evolution

hominins

a group consisting of humans and the extinct species that are more closely related to us than to chimpanzees

bipedalism

walking on two legs