What is "neodiapsida"

Neodiapsida is a clade, or major branch, of the reptilian family tree and includes all diapsids apart from some early primitive types known as the araeoscelidians.

In phylogenetic systematics, they are variously defined as the common ancestor and all its descendants of Younginiforms and "crown diapsids" (the common ancestor of lizards, crocodilians and birds, and all their descendants) [Callaway 1997], or all diapsids that are more closely related to Sauria than to Araeoscelidia (Laurin and Gauthier 2000).

Early or basal Permian neodiaspids were lizard-like, but already include specialised forms for swimming ( Claudiosaurus) and gliding ( Coelurosauravidae), as well as more conventional lizard-like forms ( Youngina etc.). Before the end of the Permian, the neodiapsids give rise to the main branches of the diapsid evolutionary tree, the lepidosaurs and archosaurs.