Neodiapsida

Reconstruction of the Late Permian Youngina capensis by Brad McFeeters.

Belongs within: Diapsida.
Contains: Lepidosauromorpha, Archosauromorpha.

The Neodiapsida is the clade containing the crown group of living diapsid reptiles (the Sauria) together with the basal 'Younginiformes' (Senter 2004). The Younginiformes are a group of lizard-like reptiles known from the late Permian and early Triassic whose monophyly relative to Sauria is uncertain. One group within this assemblage, the Tangasaurinae, was adapted to a freshwater aquatic habitat, with webbed feet and a laterally compressed tail.

Synapomorphies (from Senter 2004): posterior trunk ribs holocephalous; maximum of 17 dorsal vertebrae; pronounced olecranon process absent.

<==Neodiapsida [Younginiformes]
    |  i. s.: Heleosuchus E88
    |--+--Acerosodontosaurus Currie 1980 NB17, E88
    |  |    `--A. piveteaui NB17
    |  `--Sauria S04
    |       |  i. s.: Tapaya hernandesi Girard 1858 DS89
    |       |--Lepidosauromorpha E88
    |       `--Archosauromorpha S04
    `--+--Youngina Broom 1914 [incl. Youngoides, Youngopsis] E88
       |    `--Y. capensis S04
       `--Tangasauridae E88
            |--Kenyasaurinae E88
            |    |--Kenyasaurus E88
            |    `--Thadeosaurus Piveteau 1926 E88, D07
            |         `--T. colcanapi D07
            `--Tangasaurinae E88
                 |--Tangasaurus E88
                 `--Hovasaurus Piveteau 1926 E88, D07
                      `--H. boulei D07

*Type species of generic name indicated

REFERENCES

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[DS89] Dundee, H. A., & H. M. Smith. 1989. Nomenclatural eponym endings revisited. Systematic Zoology 38 (3): 279–283.

[E88] Evans, S. E. 1988. The early history and relationships of the Diapsida. In: Benton, M. J. (ed.) The Phylogeny and Classification of the Tetrapods vol. 1. Amphibians, Reptiles, Birds pp. 221–260. Clarendon Press: Oxford.

[NB17] Nesbitt, S. J., R. J. Butler, M. D. Ezcurra, P. M. Barrett, M. R. Stocker, K. D. Angielczyk, R. M. H. Smith, C. A. Sidor, G. Niedźwiedzki, A. G. Sennikov & A. J. Charig. 2017. The earliest bird-line archosaurs and the assembly of the dinosaur body plan. Nature 544: 484–487.

[S04] Senter, P. 2004. Phylogeny of Drepanosauridae (Reptilia: Diapsida). Journal of Systematic Palaeontology 2: 257–268.

Last updated: 11 August 2017.