(of reptiles) having two openings in the skull behind each eye, characteristic of the subclasses Lepidosauria and Archosauria, including all living reptiles except turtles.
a diapsid reptile.
Compare anapsid.

< Neo-Latin Diapsida (1903); see di-1, anapsid

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diapsid  [%PREMIUM_LINK%]     (dī-āp'sĭd)  Pronunciation Key 
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 anapsid, synapsid, therapsid.

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Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Example sentences
However, there are two other possibilities that would bring turtles into the diapsid fold.
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