Aturia

Aturia is characterized by a smooth, highly involute, discoidal shell with a complex suture and subdorsal siphuncle.

The shell of Aturia is rounded ventrally and flattened laterally; the dorsum is deeply impressed.

The siphuncle is moderate in size and located subdorsally in the adapical dorsal flexture of the septum.

Based on the feeding and hunting behaviors of living nautiluses, Aturia most likely preyed upon small fish and crustaceans.

Aturia is likely derived from species of the genus Aturoidea of the family Hercoglossidae.

Comparisons of the nautilid cephalopods Nautilus cookanum (top) and A. alabamensis (bottom), from the Late Eocene Hoko River Formation, Oregon.