The Proterochampsidae, or proterochampsids, are a group of mysterious archosauromorphs named in 1966 by A.S. Romer in his book Vertebrate Paleontology, 3rd edition. Various authorities place them as archosaurs (Benton 1985, Benton 1990), Proterosuchia (Carroll 1988), the Archosauriformes (Sereno 1991), and more recently by certain online databases as either a non-extant taxon or a Crocodylomorph. The family (and rarely order) are based on around fifty specimens from Argentina and surrounding areas of Patagonia. Known specimens are estimated to be between 245 and 199.6 Ma- placing them in the Triassic period.