Atractosteus

The genus first appeared during the Santonian stage of the Late Cretaceous, having diverged from Lepisosteus earlier in the Cretaceous. Atractosteus survived the Cretaceous-Paleogene extinction event, with one articulated fossil of the species A. grandei being recovered from strata dated to just a few thousand years after the extinction event, making it the oldest known articulated vertebrate fossil from the Cenozoic. It was found throughout North America and Europe during the Paleogene, but by the Neogene this had shrunk to only certain parts of North America, where it is still found today. ==Systematics==

}} Species Extant species Fossil species '', an Eocene-aged fossil species from the Green River Formation (=A. strausi'') The following fossil species are known: Former fossil species: • †Atractosteus cuneatus (Cope 1884) non (Cope 1878) (now in Cuneatus) • †Atractosteus falipoui (Cavin & Brito 2001) (now in Oniichthys) Dubious fossil species • †"Atractosteus" africanus (Arambourg & Joleaud, 1943) (nomen dubium, placement in Atractosteus disputed, often placed in the dubious genus Paralepisosteus) • †"Atractosteus" emmonsi Hay 1929 (Miocene of North Carolina, nomen dubium) • †"Atractosteus" lapidosus Hay 1919 (Pleistocene of Florida, nomen dubium) • †Atractosteus occidentalis (Leidy 1856) non Wiley 1976 (Campanian of Montana, nomen dubium) The extinct nomen dubium fossil species A. strausi (Kinkelin, 1884) is based on a single Miocene-aged gar scale from Germany, and has often been used as the species for the Atractosteus gars from the older Messel Formation. Although this scale provides evidence for gars surviving in Europe as late as the Miocene, it is not diagnostic enough to be considered a member of Atractosteus, nor can the Messel gars (now placed in A. messelensis) be confidently placed in it. ==References==