synapsid(redirected from Synapsids)
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Related to Synapsids: Diapsids
Any of a group of amniote vertebrates that first emerged in the late Permian Period, characterized by a single opening in the temporal region on each side of the skull and including the mammals along with various extinct groups more closely related to mammals than to other amniotes.
[New Latin Synapsida, taxon name : syn- + Greek hapsis, hapsid-, arch (from the former belief that the single temporal opening on each side of the synapsid skull evolved by the fusion of the two temporal openings on each side of the diapsid skull ); see apsis.]
(Palaeontology) a fossil reptile (of the subclass Synapsida) that exhibits some mammal-like characteristics of the skull
(Palaeontology) relating to fossil reptiles of the subclass Synapsida
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|Noun||1.||synapsid - extinct reptile having a single pair of lateral temporal openings in the skull|
reptile, reptilian - any cold-blooded vertebrate of the class Reptilia including tortoises, turtles, snakes, lizards, alligators, crocodiles, and extinct forms
ictodosaur - intermediate in form between the therapsids and most primitive true mammals
pelycosaur - large primitive reptile having a tall spinal sail; of the Permian or late Paleozoic in Europe and North America
edaphosaurus - heavy-bodied reptile with a dorsal sail or crest; of the late Paleozoic
dimetrodon - carnivorous dinosaur of the Permian in North America having a crest or dorsal sail