Scientific name Lepidosauromorpha Phylum Chordata | Rank Infraclass | |
Clade LepidosauromorphaBenton, 1983 Lower classifications Scaled reptiles, Snake, Lizard, Rhynchocephalia, Chameleons | ||
Lepidosauromorpha is a group of reptiles comprising all diapsids closer to lizards than to archosaurs (which include crocodiles and birds). The only living sub-group is the Lepidosauria: extant lizards, snakes, amphisbaenians and tuataras.
Lepidosauromorpha are distinguishable from Archosauromorphs (archosaurs) by their primitive sprawling gait, which allows for the same sinusoidal trunk and tail movement seen in fish, the sliding "joint" between the coracoids and the sternum (for a longer stride), and their pleurodont dentition. In contrast, Archosauromorphs possess a parasagittal gait, a reduction in their dermal girdle, a reduction and/or loss of the sternum, and a more thecodont dentition.
Lepidosauromorpha have retained cold blood because of their low-energy sprawling stance.
