diapsid
(noun)
any of very many reptiles and birds that have a pair of openings in the skull behind each eye
Examples of diapsid in the following topics:
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Evolution of Amniotes
- Sauropsids include reptiles and birds and can be further divided into anapsids and diapsids.
- Anapsids have no temporal fenestrae, synapsids have one, and diapsids have two.
- The diapsids include birds and all other living and extinct reptiles.
- The image illustrates the differences in the skulls and temporal fenestrae of anapsids, synapsids, and diapsids.
- Anapsids have no openings, synapsids have one opening, and diapsids have two openings.
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Evolution of Reptiles
- Soon after the first amniotes appeared, they diverged into three groups (synapsids, anapsids, and diapsids) during the Permian period.
- The Permian period also saw a second major divergence of diapsid reptiles into archosaurs (predecessors of crocodilians and dinosaurs) and lepidosaurs (predecessors of snakes and lizards).
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Evolution of Birds
- Birds are diapsids, meaning they have two fenestrations, or openings, in their skulls.
- Birds belong to a group of diapsids called the archosaurs, which also includes crocodiles and dinosaurs.