Anapsid

For the extinct fish, see Anaspid.

Anapsids Temporal range: Late Carboniferous to Late Triassic
Anapsid skull
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Amniota
Clade:	Sauropsida Williston, 1917
Subgroups
†Captorhinidae †Protorothyrididae †Parareptilia †Mesosauria †Millerosauria †Procolophonomorpha Testudines (Turtles, tortoises & terrapins)
Excluded
Diapsida

An anapsid is an amniote whose skull lacks one or more skull openings (fenestra, or fossae) near the temples. 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.