A new fossil species of Ictiobus (Teleostei: Catostomidae) from Pliocene lacustrine sediments near Tula de Allende, Hidalgo, Mexico

A new fossil Ictiobius species is described, based on an abundant collection of well-preserved isolated bones found in lacustrine deposits of Pliocene (Blancan) age near Tula de Allende, state of Hidalgo, central Mexico. This fossil Ictiobus species shows the diagnostic character of the genus. In the palatine bone the ethmoid process is longer than the premaxillary process. Suspensorial pleural ribs with trapezoidal shape and a dentary bone with extremely short and wide gnathic ramus are the characters that support the creation of this new Ictiobus species. The fossil record of Ictiobus, the first known in Mexico, extends the paleogeographical distribution known of this genus, which had been previously restricted to the USA.