• Science • People
Non User
 • Locations • Timeline
Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Home > Anapsid

Anapsids

Scientific classification
Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebrata
Infraphylum:Tetrapoda
Microphylum:Amniota
Nanophylum:Sauropsida
Superclass:Anapsida
Orders

Testudines (Turtles)
Millerettid - extinct
Nyctiphruret - extinct
Pareiasaur - extinct
Procolophonoid - extinct

The anapsids are a group of amniotes, characterized by skulls without openings near the temples. The only extant members are the Testudines - turtles, tortoises, and terrapins. Various other groups, however, are known from Permian and Triassic fossils. The anapsids have traditionally been treated as a subclass of the class Reptilia, but as this group is paraphyleticIn phylogenetics, a grouping of organisms is said to be paraphyletic if all the members of the group have a common ancestor but the group does not include all the descendants of the common ancestor. Groups which include all the descendants of a common anc they are sometimes placed in a separate class Anapsida.

Most of the anapsid orders, including the millerettid s, nyctiphruret s, and pareiasaur s, were extincted in the late Permian period by the Permian-Triassic extinction eventThe Permian-Triassic extinction event was an extinction event that occurred approximately 252 million years ago (mya), forming the boundary of the Permian and Triassic periods. It was the Earth's most severe extinction event, with about 90 percent of all. Both the procolophonoid s and some ancient ancestors of the testudines managed to survive into the Triassic, and the testidunes are the only surviving order.

External links



Read more »

Topics: Anapsid, Guides, Tutorials...
Non User