diapsid

di·ap·sid  (d-psd)

n.

Any of various reptiles having a skull with two pairs of temporal openings and including the lizards, snakes, crocodiles, dinosaurs, and pterosaurs.

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[New Latin Diapsida, former subclass name : di-¹ + Greek hapsis, hapsid-, loop, arch; see apsis.]

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di·apsid adj.

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diapsid  (d-psd)

Any of various reptiles having a skull with two pairs of temporal openings. Diapsids evolved in the Permian Period and grew longer and better-developed hindlimbs than forelimbs (unlike therapsids). Diapsids evolved into the archosaurs (including the dinosaurs and their descendants the birds) and all modern reptiles except turtles. Compare anapsidsynapsidtherapsid

Thesaurus

Noun

1.

diapsid - reptile having a pair of openings in the skull behind each eye diapsid reptile reptile, reptilian - any cold-blooded vertebrate of the class Reptilia including tortoises, turtles, snakes, lizards, alligators, crocodiles, and extinct forms Sphenodon punctatum, tuatara - only extant member of the order Rhynchocephalia of large spiny lizard-like diapsid reptiles of coastal islands off New Zealand saurian - any of various reptiles of the suborder Sauria which includes lizards; in former classifications included also the crocodiles and dinosaurs archosaur, archosaurian, archosaurian reptile - extinct reptiles including: dinosaurs; plesiosaurs; pterosaurs; ichthyosaurs; thecodonts crocodilian, crocodilian reptile - extant archosaurian reptile ophidian, serpent, snake - limbless scaly elongate reptile; some are venomous anapsid, anapsid reptile - primitive reptile having no opening in the temporal region of the skull; all extinct except turtles