Turrilites costatus

Turrilites (Turrilites) costatus is a species of helically coiled ammonoid cephalopod, from the lower part of the Upper Cretaceous (Cenomanian).

Description
The shell of this species can reach a length of about 11 cm. It  is tightly wound in a high trochospiral, with an acute angle at the apex. Ribs are weak, with rows of strong tubercles.