Hyposaurus

Hyposaurus is a genus of extinct marine dyrosaurid crocodyliform. Fossils have been found in Paleocene aged rocks of the Iullemmeden Basin in West Africa, Campanian–Maastrichtian (Late Cretaceous) Shendi Formation of Sudan and Maastrichtian (Late Cretaceous) through Danian (Early Paleocene) strata in New Jersey, Alabama and South Carolina. With an Indeterminate species from the Mid to Late Palaeocene Teberemt Formation of Mali. Isolated teeth comparable to Hyposaurus have also been found in Thanetian (Late Paleocene) strata of Virginia. It was related to Dyrosaurus. The priority of the species H. rogersii has been debated, however there is no sound basis for the recognition of more than one species from North America. The other North American species (i.e. H. fraterculus, H. ferox and H. natator) are therefore considered nomina vana (i.e. empty names).

== Introduction == Hyposaurus is an extinct reptile whose fossils are found in marine sediments from the Maastrichtian (latest Cretaceous age) to the Danian (earliest Paleocene age). It is a mesosuchian crocodyliform in the family Dyrosauridae. It is closely related to dyrosaurs and congosaurs (Schwarz-Wings). The earliest fossils were found in North America, and they were later discovered in Africa and South America. The genus is believed to have originated in Africa. Hyposaurus lived in a shallow, near shore marine environment and has many aquatic adaptations In 2009, the disorganized phylogeny of crocodyliforms was treated and reliable diagnostic traits established, but remaining questions are unanswered.