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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.]
(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]
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)]
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|Noun||1.||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