Chapter 19 Flashcards
A shelled egg in which an embryo develops within a fluid-filled amniotic sac and is nourished by yolk; produced by reptiles, birds, and egg-laying mammals, it enables them to complete their life cycles on dry land.
Amniotic Egg
Member of a clade of tetrapods that have an amniotic egg containing specialized membranes that protect the embryo. These animals include mammals and birds and other reptiles.
Amniote
Member of the tetrapod class Amphibia. These animals include frogs, toads, and salamanders.
Amphibian
A member of a primate group made up of the apes (gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans) and monkeys.
Anthropoid
The first hominids; scavenger-gatherer-hunters who lived on African savannas between about 4.4 million years ago and 1.5 million years ago.
Australopithecines
Member of the class Chondrichthyes, vertebrates with skeletons made mostly of cartilage, such as sharks and rays.
chondrichthyan
Member of the phylum Chordata, animals that at some point during their development have a dorsal hollow nerve cord, a notochord, pharyngeal slits, and a post-anal tail. These animals include lancelets, tunicates, and vertebrates.
Chordate
A chordate with a head.
Craniate
An animal that warms itself mainly by absorbing heat from its surroundings.
Ectotherm
Referring to organisms that do not produce enough metabolic heat to have much effect on body temperature.
Ectothermic
Placental mammal; mammal whose young complete their embryonic development within the uterus, joined to the mother by the placenta.
Eutherian
A species on the human branch of the evolutionary tree; a member of the family Hominidae, including Homo sapiens and our ancestors.
Hominid
A row of sensory organs along each side of a fish’s body. Sensitive to changes in water pressure, it enables a fish to detect minor vibrations in the water.
Lateral line system
A bony fish with strong, muscular fins supported by bones.
Lobe-fin
Member of the class Mammalia, amniotes that possess mammary glands and hair.
Mammal
A pouched mammal, such as a kangaroo, opossum, or koala. These animals give birth to embryonic offspring that complete development while housed in a pouch and attached to nipples on the mother’s abdomen.
Marsupial
An egg-laying mammal, such as the duck-billed platypus.
Monotreme
A protective flap on each side of a fish’s head that covers a chamber housing the gills.
Operculum
An arrangement of the fingers such that the thumb can touch the ventral surface of the fingertips of all four fingers.
Opposable thumb
The study of human origins and evolution.
Paleoanthropology
In most mammals, the organ that provides nutrients and oxygen to the embryo and helps dispose of its metabolic wastes; formed of the embryo’s chorion and the mother’s endometrial blood vessels.
Placenta
Young animals complete their embryonic development in the uterus, nourished via the mother’s blood vessels in this tissue type; also called a eutherian.
Placental mammal
A bony fish having fins supported by thin, flexible skeletal rays.
Ray-finned fish
Member of the clade of amniotes that includes snakes, lizards, turtles, crocodilians, and birds, along with a number of extinct groups such as dinosaurs.
Reptiles
A gas-filled internal sac that helps bony fishes maintain buoyancy.
Swim bladder
A vertebrate with two pairs of limbs. These animals include mammals, amphibians, and birds and other reptiles.
Tetrapods
One of a series of segmented skeletal units that enclose the nerve cord, making up the backbone of the animal.
Vertebra
backbone; composed of a series of segmented units.
Vertebral column
A chordate animal with a backbone. These animals include lampreys, chondricthyans, ray-finned fishes, lobe-fin fishes, amphibians, reptiles (including birds), and mammals.
Vertebrate
