Anapsid

Anapsids; Temporal range: Late Carboniferous to Late Triassic ; Range possibly includes turtles
	Anapsid skull
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Informal group:	Anapsida; Williston, 1917
Subgroups
	†Captorhinidae; †Protorothyrididae; †Parareptilia †Mesosauria; †Millerosauria; †Procolophonomorpha; ; Testudines (Turtles, tortoises & terrapins);

An anapsid is an amniote whose skull lacks one or more skull openings (fenestra, or fossae) near the temples.^[1] Traditionally, the Anapsida are considered the most primitive subclass of amniotes, the ancestral stock from which Synapsida and Diapsida evolved, making anapsids paraphyletic. It is, however, doubtful that all anapsids lack temporal fenestra as a primitive trait, and that all the groups traditionally seen as anapsids truly lacked fenestra.

^ Pough, F. H. et al. (2002) Vertebrate Life, 6th ed. Upper Saddle River, New Jersey: Prentice Hall. ISBN 0-13-041248-1

[1] Pough, F. H. et al. (2002) Vertebrate Life, 6th ed. Upper Saddle River, New Jersey: Prentice Hall. ISBN 0-13-041248-1

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