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5.9.9: Key Terms

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    97181
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    Acanthostega
    one of the earliest known tetrapods
    Actinopterygii
    ray-finned fishes
    allantois
    membrane of the egg that stores nitrogenous wastes produced by the embryo; also facilitates respiration
    amnion
    membrane of the egg that protects the embryo from mechanical shock and prevents dehydration
    amniote
    animal that produces a terrestrially adapted egg protected by amniotic membranes
    Amphibia
    frogs, salamanders, and caecilians
    ampulla of Lorenzini
    sensory organ that allows sharks to detect electromagnetic fields produced by living things
    anapsid
    animal having no temporal fenestrae in the cranium
    anthropoid
    monkeys, apes, and humans
    Anura
    frogs
    apocrine gland
    scent gland that secretes substances that are used for chemical communication
    Apoda
    caecilians
    Archaeopteryx
    transition species from dinosaur to bird from the Jurassic period
    archosaur
    modern crocodilian or bird, or an extinct pterosaur or dinosaur
    Australopithecus
    genus of hominins that evolved in eastern Africa approximately four million years ago
    brachiation
    movement through trees branches via suspension from the arms
    brumation
    period of much reduced metabolism and torpor that occurs in any ectotherm in cold weather
    caecilian
    legless amphibian that belongs to the clade Apoda
    Casineria
    one of the oldest known amniotes; had both amphibian and reptilian characteristics
    Catarrhini
    clade of Old World monkeys
    Cephalochordata
    chordate clade whose members possess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail in the adult stage
    Chondrichthyes
    jawed fish with paired fins and a skeleton made of cartilage
    Chordata
    phylum of animals distinguished by their possession of a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some point during their development
    chorion
    membrane of the egg that surrounds the embryo and yolk sac
    contour feather
    feather that creates an aerodynamic surface for efficient flight
    Craniata
    clade composed of chordates that possess a cranium; includes Vertebrata together with hagfishes
    cranium
    bony, cartilaginous, or fibrous structure surrounding the brain, jaw, and facial bones
    Crocodilia
    crocodiles and alligators
    cutaneous respiration
    gas exchange through the skin
    dentary
    single bone that comprises the lower jaw of mammals
    diapsid
    animal having two temporal fenestrae in the cranium
    diphyodont
    refers to the possession of two sets of teeth in a lifetime
    dorsal hollow nerve cord
    hollow, tubular structure derived from ectoderm, which is located dorsal to the notochord in chordates
    down feather
    feather specialized for insulation
    eccrine gland
    sweat gland
    Enantiornithes
    dominant bird group during the Cretaceous period
    eutherian mammal
    mammal that possesses a complex placenta, which connects a fetus to the mother; sometimes called placental mammals
    flight feather
    feather specialized for flight
    frog
    tail-less amphibian that belongs to the clade Anura
    furcula
    wishbone formed by the fusing of the clavicles
    gnathostome
    jawed fish
    Gorilla
    genus of gorillas
    hagfish
    eel-like jawless fish that live on the ocean floor and are scavengers
    heterodont tooth
    different types of teeth that are modified for different purposes
    hominin
    species that are more closely related to humans than chimpanzees
    hominoid
    pertaining to great apes and humans
    Homo
    genus of humans
    Homo sapiens sapiens
    anatomically modern humans
    Hylobatidae
    family of gibbons
    Hylonomus
    one of the earliest reptiles
    lamprey
    jawless fish characterized by a toothed, funnel-like, sucking mouth
    lancelet
    member of Cephalochordata; named for its blade-like shape
    lateral line
    sense organ that runs the length of a fish’s body; used to detect vibration in the water
    lepidosaur
    modern lizards, snakes, and tuataras
    mammal
    one of the groups of endothermic vertebrates that possesses hair and mammary glands
    mammary gland
    in female mammals, a gland that produces milk for newborns
    marsupial
    one of the groups of mammals that includes the kangaroo, koala, bandicoot, Tasmanian devil, and several other species; young develop within a pouch
    monotreme
    egg-laying mammal
    Myxini
    hagfishes
    Neognathae
    birds other than the Paleognathae
    Neornithes
    modern birds
    notochord
    flexible, rod-shaped support structure that is found in the embryonic stage of all chordates and in the adult stage of some chordates
    Ornithorhynchidae
    clade that includes the duck-billed platypus
    Osteichthyes
    bony fish
    ostracoderm
    one of the earliest jawless fish covered in bone
    Paleognathae
    ratites; flightless birds, including ostriches and emus
    Pan
    genus of chimpanzees and bonobos
    Petromyzontidae
    clade of lampreys
    pharyngeal slit
    opening in the pharynx
    Platyrrhini
    clade of New World monkeys
    Plesiadapis
    oldest known primate-like mammal
    pneumatic bone
    air-filled bone
    Pongo
    genus of orangutans
    post-anal tail
    muscular, posterior elongation of the body extending beyond the anus in chordates
    primary feather
    feather located at the tip of the wing that provides thrust
    Primates
    order of lemurs, tarsiers, monkeys, apes, and humans
    prognathic jaw
    long jaw
    prosimian
    division of primates that includes bush babies and pottos of Africa, lemurs of Madagascar, and lorises of Southeast Asia
    salamander
    tailed amphibian that belongs to the clade Urodela
    Sarcopterygii
    lobe-finned fish
    sauropsid
    reptile or bird
    sebaceous gland
    in mammals, a skin gland that produce a lipid mixture called sebum
    secondary feather
    feather located at the base of the wing that provides lift
    Sphenodontia
    clade of tuataras
    Squamata
    clade of lizards and snakes
    stereoscopic vision
    two overlapping fields of vision from the eyes that produces depth perception
    swim bladder
    in fishes, a gas filled organ that helps to control the buoyancy of the fish
    synapsid
    mammal having one temporal fenestra
    Tachyglossidae
    clade that includes the echidna or spiny anteater
    tadpole
    larval stage of a frog
    temporal fenestra
    non-orbital opening in the skull that may allow muscles to expand and lengthen
    Testudines
    order of turtles
    tetrapod
    phylogenetic reference to an organism with a four-footed evolutionary history; includes amphibians, reptiles, birds, and mammals
    theropod
    dinosaur group ancestral to birds
    tunicate
    sessile chordate that is a member of Urochordata
    Urochordata
    clade composed of tunicates
    Urodela
    salamanders
    vertebral column
    series of separate bones joined together as a backbone
    Vertebrata
    members of the phylum Chordata that possess a backbone

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