Turrilites

Turrilites is a genus of helically coiled ammonoid cephalopods from the lower part of the Upper Cretaceous ; generally included in the Ancyloceratina. Previously it was included in the ammonoid suborder, Lytoceratina.
The shell of Turrilites is tightly wound in a high trochospiral, with an acute angle at the apex. Ribs are weak to strong and may have 3 or 4 rows of equal numbers of tubercles. Thought to be derived from Mariella. Includes three subgenera.

Subgenera and species

Turrilites has three subgenera. Turrilites (Turrilites) Lamarck, 1801

* Turrilites acutus Passy, 1832
* Turrilites (Turrilites) costatus Lamarck, 1801
* Turrilites scheuchzerianus Bosc, 1801Turrilites (Euturrilites) Breistroffer, 1953Turrilites (Mesoturrilites)

Subgenus Turrilites has weak ribs and strong tubercles. Subgenus Euturrilites has strong ribs, commonly depressed in middle, especially on early whorls, and no tubercles. Subgenus Mesoturrilites has almost no ribs and clavate tubercles that tend to form spiral ridges.