{{Automatic taxobox | fossil_range = Late Norian–Rhaetian~ | image = Avicranium skull views.jpg | image_caption = A 3D reconstruction of Avicraniums skull in multiple views. | taxon = Avicranium | authority = Pritchard & Nesbitt, 2017 | type_species = Avicranium renestoi | type_species_authority = Pritchard & Nesbitt, 2017 }}Avicranium is a genus of extinct drepanosaur reptile known from the Chinle Formation of the late Triassic. The type species of Avicranium is Avicranium renestoi'''. "Avicranium" is Latin for "bird cranium", in reference to its unusual bird-like skull, while "renestoi" references Silvio Renesto, a paleontologist known for studies of Italian drepanosaurs. Discovery The holotype and only known specimen of Avicranium is AMNH FARB 30834, a disarticulated skull attached to a few cervical (neck) vertebrae. This specimen hails from the Coelophysis (or Whitaker) quarry at Ghost Ranch in New Mexico, USA. This quarry belongs to the 'siltstone member' of the Chinle formation, which corresponds to the late Norian to early Rhaetian stages of the Triassic. Various unprepared blocks from this locality were excavated by American Museum of Natural History field parties during the 1940s. Long believed to only contain multiple specimens of the early dinosaur Coelophysis, these blocks are now known to contain a multitude of different Triassic reptiles. AMNH FARB 30834 was uncovered during the preparation of a block containing the holotype of Effigia okeeffeae, a large shuvosaurid pseudosuchian. Multiple other drepanosaur vertebrae and limb fragments have also been found in the block, although it is unclear whether they belong to the same specimen as AMNH FARB 308344. Despite AMNH FARB 30834 being disarticulated and partially covered by the rock matrix, many of its bones are well-preserved and the specimen as a whole was micro-CT scanned, revealing elements hidden under rock. This scan allowed the skull to be reconstructed in 3D using digital software. An endocast of the brain was also digitally constructed from the skull. Avicranium has the most well-preserved skull material of any drepanosaur. Description AMNH FARB 30834 can be recognized as a drepanosaur due to several traits of its vertebrae. The articular surfaces of its vertebral centres are heterocoelous (saddle-shaped). The neural spines are anteroposteriorly short and strongly anterodorsally inclined. These features closely resemble those of Drepanosaurus. However, the most notable feature of AMNH FARB 30834 is its skull, which shares many similarities with the skulls of modern birds. The snout is slender and tapering, similar to that of