* Traditionally a monophyletic clade, the present author considers that, on stratigraphica nd morphological grounds, the Araeoscelida are better understood as a grade of early diapsids. In which case, phylogenetically and cladistically speaking, Aeroscelida = Diapsida.
Araeoscelida: Aphelosaurus, Araeoscelis, Kadaliosaurus, Petrolacosaurus, Spinoaequalis, Zarcasaurus. Most basal diapsids?
Lizard-like; some euryapsid (upper temporal fenestra only), but jugal still bifurcated; long necks, with great elongation of neck in some; gracile, presumably cursorial, limbs.
Comments: a number of poorly known very forms have been placed here, making the group something of a "wastebasket taxon". Most certainly a paraphyletic basal assemblage; also spelt "Araeoscelidia", here we are using Williston (1913)'s original spelling.
Links: Palaeocritti, Paleobiology database, Wikipedia, UCMP - Basal Diapsids (only a paragraph), MAK101001.
Araeoscelis Araeoscelis gracilis
euryapsid (upper temporal fenestra only).
Comments: At one time considered to be the ancestor of sauropterygia, because of the euryapsid style openings.
Links: Palaeocritti, Wikipedia, About com Dinosaurs MAK101001
Comments: The earliest known diapsid. Unlike the closely related Araeoscelis, it shows the typical diapsid condition with two temporal fenestrae in the skull.
Links: Palaeocritti, Wikipedia, Prehistoric Land Reptiles - Planet Dinosaur, David Peters - Reptile Evolution MAK101001
References: Reisz 1977, 1981
Late Carboniferous (Virgilian - Late Pennsylvanian) of N Am
deep, laterally compressed tail.
Comments: The earliest known aquatic reptile. It probably swam using its flattened, fanned tail. Found in association with marine fish..
checked ATW031003, revised MAK111116
Using this material. All material by ATW is public domain and may be freely used in any way (also any material jointly written by ATW and MAK). All material by MAK is licensed Creative Commons Attribution License Version 3.0, and may be freely used provided acknowedgement is given. All Wikipedia material is either Gnu Open Source or Creative Commons (see original Wikipedia page for details). Other graphics are copyright their respective owners