Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Any of various reptiles of the order Therapsida of the Permian and Triassic periods, many of which are considered to be direct ancestors of mammals.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Any extinct reptile of the order Therapsida; thought to be direct ancestors of the mammals

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. probably warm-blooded; considered direct ancestor of mammals

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

From New Latin Thērapsida, order name : Greek thēr, wild animal; see theropod + Greek hapsis, hapsid-, arch, vault (from the enlarged lower temporal opening characteristic of the order); see apsis.

Examples

  • Descended from creatures called therapsid reptiles, bats first took flight in the Triassic period more than two hundred million years ago.

    Going Mutant

  • My first therapsid drawings were downright atrocious.

    Life's Time Capsule: The Long Road to Failure

  • His book “From the Beginning” was also a surprisingly detailed introduction to extinct fish, reptile, and therapsid art.

    Life's Time Capsule: Member Bio: Nima Sassani

  • “We arbitrarily group the therapsids as reptiles we have to draw a line somewhere but were they alive, a typical therapsid probably would seem to us an odd cross between a lizard and a dog, a transitional type between the two great groups of backboned animals.”

    Semmelweis: ID hero - The Panda's Thumb

  • Gish makes one final effort to discredit the therapsid-mammal links: Many of the diagnostic features of mammals, of course, reside in their soft anatomy or physiology.

    What a difference a day makes. - The Panda's Thumb

  • As Romer puts it, “We arbitrarily group the therapsids as reptiles we have to draw a line somewhere but were they alive, a typical therapsid probably would seem to us an odd cross between a lizard and a dog, a transitional type between the two great groups of backboned animals.”

    What a difference a day makes. - The Panda's Thumb

  • Because the fossil evidence of the transition from therapsid to mammal is extensive, detailed and well-studied, it is not surprising that most creationists make no mention of it.

    What a difference a day makes. - The Panda's Thumb

  • The entire series of therapsid transitionals are each fully functional, completely capable of chewing their food and detecting airborne sounds just as modern snakes eat with a double jaw joint and detect sounds through bones connected to their skull and jawbones.

    What a difference a day makes. - The Panda's Thumb

  • The therapsid-mammal transition was completed with the appearence of the morganucodonts in the late Triassic: The axes of the two jaw hinges, dentary-squamosal and articular-quadrate, coincide along a lateral-medial line, and therefore the double jaw articulation of the most advanced cynodonts is still present … The secondary dentary-squamosal jaw hinge had enlarged in the morganucodonts and took a greater proportion if not all of the stresses at the jaw articulation.

    What a difference a day makes. - The Panda's Thumb

  • Thus, the fossil record demonstrates, during the transition from therapsid reptile to mammal, various bones in the skull slowly migrated together to form a second functional jaw joint, and the now-superfluous original jaw bones were reduced in size until they formed the three bones in the mammalian middle ear.

    What a difference a day makes. - The Panda's Thumb

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