Gracilisuchus

Gracilisuchus — slender, long (one) [L. gracilis = slender; Gk. sυchnós (via irregular derivation) = long] is an extinct genus of tiny (30 cm long) pseudosuchian (a group which includes the ancestors of crocodilians) from the Middle Triassic. It is placed in the clade Suchia, close to the ancestry of crocodylomorphs. Gracilisuchus was thought to be a dinosaur, but this hypothesis has since been rejected. Its fossils were first discovered in the 1970s. Many features in the hindlimbs of Gracilisuchus are also found in a group of primitive crocodylomorphs called sphenosuchians. Sphenosuchians are usually considered a paraphyletic chain of successively primitive crocodylomorphs, but the features they share in common with Gracilisuchus suggest Sphenosuchia and Gracilisuchus may form a monophyletic grouping, or valid clade, of crocodylomorphs. A recent paper places the genus in the new family Gracilisuchidae, along with the genera Turfanosuchus and Yonghesuchus near the base of the Suchia.