diapsid

[dahy-ap-sid]

adjective

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

noun

1. a diapsid reptile.

diapsid

1. Any of various amniotes 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, in some classifications, the turtles.

2. Compare anapsid synapsid therapsid

Word History and Origins

Origin of diapsid¹

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

Example Sentences

It's still unclear which group of modern-day vertebrates are the closest relative to ichthyosaurs, but researchers have suggested they may have been an offshoot of diapsids, which includes dinosaurs, birds and pterosaurs.

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It's still unclear which group of modern-day vertebrates are the closest relative to ichthyosaurs, but researchers have suggested they may have been an offshoot of diapsids, which includes dinosaurs, birds, and pterosaurs.

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Cranial kinesis in dinosaurs: intracranial joints, protractor muscles, and their significance for cranial evolution and function in diapsids.

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A tiny Triassic saurian from Connecticut and the early evolution of the diapsid feeding apparatus.

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That diapsid group includes crocodiles, lizards, snakes, dinosaurs, and their surviving kin, birds.

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