on the lateral surface of the ilium above the acetabulum. This ridge is a defining characteristic of rauisuchians, forming a buttress over the femur and giving these animals a pillar-erect stance. Other features of Smok seem to exclude it from these groups of archosaurs. The premaxilla and maxilla of the upper jaw attach closely to each other, making a continuous row of evenly spaced teeth. Early theropods and orthithosuchids have a toothless gap between the premaxilla and the maxilla, distinguishing them from Smok. The upper jaw bones of rauisuchians are not closely connected, leaving a small opening between the premaxilla and maxilla that is not seen in Smok. Unlike many pseudosuchids and theropods, Smok does not have pneumatic areas, or air pockets, in the braincase. It also has several features that link it with primitive archosauromorphs, including the presence of a postfrontal bone on the skull and a closed acetabulum in the hip. Discovery and naming Smok was found in a locality near Lisowice village that is latest Norian to early Rhaetian in age. This area was known to contain Triassic fossils since it was formally described in 2008. The first material of Smok, the jawbone and fragments of the skull, was discovered in 2007. It was first described in 2008 as a theropod dinosaur based on features in its braincase and frontal bone. The material was also thought to represent two individuals. Similarities were noted between the braincase of the animal and that of allosauroids. When the discovery was first announced, it was called "the Dragon of Lisowice" and was purported to be the first member of a line of dinosaurs that led to Tyrannosaurus rex. Bones from other parts of the body were found in 2009 and 2010. Five tracks made by a three-toed archosaur – presumably a theropod dinosaur – were found in rocks that were above the layer where Smok was found. The footprints may belong to Smok, but the lack of foot bones in the skeleton make this association uncertain. Smok is known from the holotype ZPAL V.33/15, a partially complete braincase which is associated with a partially preserved skeleton, including cranial and postcranial bones from the referred materials ZPAL V.33/16-56, 97-102, 295-314, 434 and 507. All specimens were found in the same location (Lipie Śląskie clay-pit Formation) and probably represent a single individual. It was first named by Grzegorz Niedźwiedzki, Tomasz Sulej and Jerzy