Paleosuchus is a South American genus of reptiles in the subfamily Caimaninae of the family Alligatoridae. They are the smallest members of the order Crocodilia in the Americas.[1]
The genus name Paleosuchus is derived from the Greek palaios meaning "ancient" and soukhos meaning "crocodile god Sobek". This refers to the belief that this crocodile comes from an ancient lineage that diverged from other species of caimans some 30 million years ago.[2]
At present, Paleosuchus contains only two members: the smooth-fronted or Schneider's dwarf caiman (Paleosuchus trigonatus) and Cuvier's dwarf caiman (Paleosuchus palpebrosus), both from South America. Paleosuchus is distinguished from other caimans in the subfamily Caimaninae by the absence of an interorbital ridge and the presence of four teeth in the premaxilla region of the jaw, where other species of caimans have five.[2] The relationships of extant (living) caimans can be shown in the cladogram below, based on molecular DNA-based phylogenetic studies:[3]
The genus contains the following two extant species[4] and a yet unnamed fossil species.[5]
| Image | Scientific name | Common name | Distribution |
|---|---|---|---|
| P. palpebrosus | Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad, and Venezuela | ||
| P. trigonatus | Amazon and Orinoco Basins | ||