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Related to therapsid: Pelycosauria, synapsid, Enterozoa


Any of various amniote vertebrates that emerged in the Permian Period and diversified in the Triassic, including the mammals, their ancestors, and their relatives.

[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 group); see apsis.]

the·rap′sid adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Palaeontology) any extinct reptile of the order Therapsida, of Permian to Triassic times: considered to be the ancestors of mammals
[C20: from New Latin Therapsida, from Greek thēr beast + Latin apsis arch]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(θəˈræp sɪd)

any of various mammallike reptiles of the extinct order Therapsida, inhabiting all continents from mid-Permian to late Triassic times.
[< New Latin Therapsida (1905) = Greek thēr-, s. of thḗr wild beast + apsid-, s. of apsís arch, vault (referring to the temporal arch of the skull) + New Latin -a neuter pl. ending (see -a1)]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.therapsid - probably warm-blooded; considered direct ancestor of mammals
synapsid, synapsid reptile - extinct reptile having a single pair of lateral temporal openings in the skull
order Therapsida, Therapsida - extinct mammal-like reptiles found inhabiting all continents from the mid Permian to late Triassic
Chronoperates paradoxus - shrew-sized protomammal from the Alberta region of Canada; from about 55 million years ago (much more recent than other mammal-like reptiles)
cynodont - small carnivorous reptiles
dicynodont - a kind of therapsid
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
"Kotelnich is one of the most important localities worldwide for finding therapsid fossils - not only because they are amazingly complete and well-preserved there, but also because they provide an all-too-rare window into mammal ancestry in the Northern Hemisphere during the Permian."
At this level, Therapsid footprints occur (Gand et al., 2000).
According to Heath, the skeletons of therapsid reptiles indicate that they had an erect, not a sprawling, stance.
"Grasses are rich in fiber and modern ruminants eat them, but in the Permian grasses didn't exist so this new therapsid probably ate stems or leaves rich in fiber that existed at the time," said Cisneros.
Although in many therapsid fossils the nasal bones have frequently been dislocated as a result of dorsoventral compression of the nasal cavity, no evidence exists of such dislocation in GS M796.
Summary: TEHRAN (FNA)- During the Triassic period (252-201 million years ago) mammal-like reptiles called therapsids co-existed with ancestors to dinosaurs, crocodiles, mammals, pterosaurs, turtles, frogs, and lizards.
The work revealed these were completely new species belonging to two different subgroups of protomammals called therapsids. These were the ancestors of modern-day mammals that lived during the Permian period, sometime between 299 to 252 million years ago.
Non-mammalian synapsids (therapsids) are represented only by the large traversodontid cynodont Arctotraversodon plemmyridon (Hopson 1984; Sues et al.