Ammonite genera

genus of molluscs (fossil)

Wikimedia list article

Diplomoceras is a genus of ammonites included in the family Diplomoceratidae. Fossils of species within this genus have been found in the Late Cretaceous sediments (age range: Campanian-Maastrichtian). D. maximum had coiled shell length about , uncoiled shell being to over , with body chamber around . Some partial specimens may belong to shell with length around . Studies of Diplomoceras suggest that members of this genus could reach lifespans of over 200 years.

Aioloceras is an ammonite, order Ammonitida, from near the end of the Early Cretaceous. The shell is compressed with the outer whorl covering much of the previous. Sides are slightly convex, converge toward a narrowly ached venter. Inner whorls have sharp falcoid ribs, outer are smooth. Umbilical tubercles are lacking. Similar related forms include Neosaynella and Cleoniceras.

genus of molluscs (fossil)

Soliclymenia is a genus of ammonites from the Late Devonian. S. paradoxa has an unusual, triangularly-coiled shell. Additional genera of ammonites with triangular shells are Kamptoclymenia, Trigonoshumardites, and Trigonogastrioceras. Soliclymenia semiparadoxa, which is known only from the holotype, is semi-triangular, the innermost whorls being circular. Other species of this genus, including S. solarioides and S. recticostata, have a circularly-coiled shell.