Original paper

First record of the North American scaphitid ammonite Discoscaphites iris from the upper Maastrichtian of Libya

Machalski, Marcin; Jagt, John W.M.; Landman, Neil H.; Uberna, Janusz


A single fragmentary macroconch of the scaphitid Discoscaphites iris (Conrad, 1858) is recorded from the upper Maastrichtian Omphalocyclus macroporus Zone in the upper portion of the Lower Tár Member of the Zimam Formation (Hammada Group) in the western Hammada al Hamra desert, northwest Libya. This record significantly extends the geographic range of D. iris; it was previously known only from upper Maastrichtian strata along the Gulf Coast and Atlantic Seaboard of North America. The size of the Libyan specimen exceeds that of all North American individuals of D. iris known to date, which suggests that it was a member of an indigenous Libyan population with North American ancestry, rather than a drift shell carried to North Africa by oceanic currents.