Younginiformes is a group of diapsid reptiles known from the Permian-Triassic of Africa and Madagascar. It has been used as a replacement for "Eosuchia".[1] Younginiformes (including Acerosodontosaurus, Hovasaurus, Kenyasaurus, Tangasaurus, Thadeosaurus and Youngina) were historically suggested to be lepidosauromorphs, but are currently thought to be basal non-saurianneodiapsids.[2][3] The group is sometimes divided into two families, Tangasauridae and Younginidae. The monophyly of the group is disputed. A 2009 study found them to be an unresolved polytomy at the base of Neodiapsida,[4] while a 2011 study recovered the group as paraphyletic.[5] A 2022 study recovered the Younginiformes as a monophyletic group of basal neodiapsid reptiles, also including Claudiosaurus and Saurosternon as part of the group.[6] Some younginiforms like Hovasaurus and Acerosodontosaurus are thought to have had an amphibious lifestyle, while others like Kenyasaurus, Thadeosaurus and Youngina were probably terrestrial.[4]
^Gauthier, J.; Estes, R.; de Queiroz, K. (1988). "A phylogenetic analysis of Lepidosauromorpha"(PDF). In R. Estes; G. Pregill (eds.). Phylogenetic relationships of the lizard families. Stanford: Stanford University Press. pp. 15–98. Archived(PDF) from the original on 2023-12-09.
^ abBickelmann; Müller; Reisz (2009). "The enigmatic diapsid Acerosodontosaurus piveteaui (Reptilia: Neodiapsida) from the Upper Permian of Madagascar and the paraphyly of "younginiform" reptiles". Canadian Journal of Earth Sciences. 46 (9): 651–661. Bibcode:2009CaJES..46..651S. doi:10.1139/E09-038.
