Characiform

Evolution

The earliest characiform fossils date back to freshwater deposits from the Late Cretaceous, from the Turonian of Uzbekistan (Bissekty Formation) and the Santonian of Hungary. Other fossil teeth date back to the Cenomanian of Morocco, but it has been suggested that these teeth may be of early ginglymodians. Previously, the oldest characiform was assumed to be Santanichthys of the Early Cretaceous (Albian Age) of Brazil. This presumably marine taxon was used as evidence of characiformes potentially having marine origins. However, more recent studies indicate that Santanaichthys is likely a basal otophysan rather than a characiform. Similarly, Salminops from Spain and Sorbinicharax from Italy, previously also considered potential marine characiforms, are now thought to have no characiform affinities and are considered indeterminate teleosts. Given this, there is no paleontological support for characiforms having marine origins. Two other alleged Eocene European characids, ProhydrocyonPiton, 1938 and ProcharacinusPiton, 1938 from France, lack a Weberian apparatus and are very likely not characins, and instead may be related to the enigmatic Thaumaturus.