Agnosphitys

Agnosphitys Temporal range: Late Triassic, 208 Ma PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Order:	Saurischia
Suborder:	†Sauropodomorpha
Family:	†Guaibasauridae
Genus:	†Agnosphitys Fraser et al., 2002
Species:	†A. cromhallensis
Binomial name
Agnosphitys cromhallensis Fraser et al., 2002

Agnosphitys (/ˌæɡnoʊsˈfaɪtᵻs/; "unknown begetter"; sometimes mistakenly called Agnostiphys or Agnosphytis) is a genus of dinosaur from the Late Triassic of Avon, England. It contains only one species, the type species A. cromhallensis. Its remains include an ilium, maxilla, astragalus and humerus, which date variously from the Norian and Rhaetian stages of the Late Triassic.

The type species, Agnosphitys cromhallensis, was described by Fraser, Padian, Walkden and Davis in 2002. The fossils, consisting of a partial skeleton including referred material, were found in Avon, England.

The remains of Agnosphitys defied precise classification in the original description; the describers placed it outside Dinosauria using the definition of Dinosauria outlined by Padian and May (1995) and provided (on p. 80) the following diagnosis: "Well-defined brevis fossa on the ilium; semi-perforate acetabulum; `kidney-shaped' antitrochanter; well-developed posterior portion of the iliac blade; two sacral vertebrae; subrectangular deltopectoral crest that is 33 per cent of the length of the humerus; astragalus with a distinct ascending process and a prominent depression immediately posterior to the ascending process; in dorsal aspect an acute anteromedial corner on the astragalus."

Despite the paucity of known fossils, Agnosphitys has been included in two phylogenetic analyses analyzing primitive dinosaur relationships. Yates (2007) recovered the genus as a theropod, whereas Ezcurra (2010) recovered it as a member of Guaibasauridae. More recently, Agnosphitys has been considered a silesaurid based on an as-yet-unpublished description of Asilisaurus.