''Turrilites'' is a genus of helically coiled

ammonoid Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

cephalopods from the lower part of the Upper Cretaceous (

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

and

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

); generally included in the

Ancyloceratina The Ancyloceratina were a diverse suborder of ammonite most closely related to the ammonites of order Lytoceratina. They evolved during the Late Jurassic but were not very common until the Cretaceous period, when they rapidly diversified and beca ...

. Previously (Arkell, 1957) it was included in the ammonoid suborder,

Lytoceratina Lytoceratina is a suborder of Jurassic and Cretaceous ammonites that produced loosely coiled, evolute and gyroconic shells in which the sutural element are said to have complex moss-like endings. Morphologic characteristics Shells are generally ...

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

References

* Arkell ''et al.'', Mesozoic Ammonoidea (L222);

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

Part L, Ammonoidea. Geological Soc. of America and Univ Kansas Press.
The Paleobiology Database ''Turrilites'' entry
{{Taxonbar, from=Q4000713 Ammonitida genera Prehistoric cephalopod genera Cretaceous ammonites Cenomanian genus first appearances Turonian genus extinctions Ammonites of Africa Ammonites of Asia Ammonites of Australia Cretaceous ammonites of Europe Cretaceous ammonites of North America Ammonites of South America Taxa named by Jean-Baptiste Lamarck Fossil taxa described in 1801 Turrilitoidea