diapsid

A diapsid is a reptile with two fenestrae (holes) behind the eye on each side of its skull.

Apsisaurus was formerly assigned as an "eosuchian" diapsid.

The current opinion is that Longisquama is an ambiguous diapsid and has no bearing on the origin of birds.

Heleosuchus may also share a thyroid fenestra with these higher diapsid reptiles as well, but the identity of this feature is disputed.

Bennett (2007) however, concluded that it has no diagnostic features of the Pterosauria, and cannot be positively identified beyond being an indeterminate diapsid.

Acerosodontosaurus is a younginiform diapsid that lived during the Upper Permian of Madagascar.

Scientists in this camp usually regard Longisquama as a curious diapsid with specialized scales, ambiguous skeletal features, and no real significance to bird evolution.

In fact, it was already a diapsid, with two openings known as "temporal fenestrae" on each side of its skull to add attachment points for jaw muscles.

Longisquama and Coelurosauravus were not found to be closely related to drepanosaurids, but instead were recovered as non-neodiapsid diapsid as in Senter's (2004) analysis.

Qianxisaurus is a genus of basal eosauropterygian diapsid known from the Middle Triassic (Ladinian stage) of China.

Orovenator is an extinct genus of diapsid from Lower Permian (Sakmarian stage) deposits of Oklahoma, USA.

Bennett found the specimen to be an indeterminate diapsid and criticized the previous authors for publishing a species name when no diagnostic characters below the class level could be verified.

Giant Diapsid: A giant, carnivorous diapsid that fought the Shimera while it was trying to get her cub.

Apart from araeoscelidans, only one other diapsid is known before the Late Permian: Orovenator from the Early Permian of Oklahoma (Reisz et al., 2011).

According to a cladistic study by Phil Senter in 2004, Longisquama would be an even more basal diapsid and a member of Avicephala, more closely related to Coelurosauravus.

Fossil remains from Svalbard from the specimen SVT 203 were originally assigned to Grippia longirostris but are know thought to have belonged to a non-ichthyopterygian diapsid related to Helveticosaurus.

Lanthanolania (meaning "forgotten butcher") is an extinct genus of diapsid from Middle Permian (Wordian stage, or upermost Kazanian in Eastern Europe) deposits of Arkhangel'sk Province, Russia.

Early primitive forms like Mesosuchus and Howesia were generally small and more typically lizard-like in build, and had skulls rather similar to the early diapsid Youngina, except for the beak and a few other features.

The presence of a postorbito-jugal bar indicates that Acallosuchus is a diapsid with the characteristic presence of two large holes in the back of the skull (the bar would have formed the anterior margins of these holes).

A diapsid reptile from the Pennsylvanian of Kansas.

Heleosaurus - Both Heleosaurus and Heleosuchus were at one time thought to be diapsid reptiles.

In nearly all diapsid reptiles the braincase is weakly connected to other bones that make up the back of the skull, making this region flexible or kinetic.

Teraterpeton evolved from diapsid reptiles with two holes at the back of their skull, the supratemporal fenestra and an infratemporal fenestra below it.

Archosaurs - a group encompassing crocodiles, pterosaurs, dinosaurs, and ultimately birds - are diapsid reptiles that first evolved from Archosauriform ancestors during the Olenekian.

All Permian anapsid reptiles died out except the procolophonids (testudines have anapsid skulls but are most often thought to have evolved later, from diapsid ancestors).

For example, as diapsids, dinosaurs ancestrally had two pairs of temporal fenestrae (openings in the skull behind the eyes), and as members of the diapsid group Archosauria, had additional openings in the snout and lower jaw.