Rakoilevia

Rakoilevia is a genus of extinct ammonites, a group of marine cephalopod molluscs. These fossils are primarily found in the Mesozoic Era, dating back to the Late Jurassic and Early Cretaceous periods. Rakoilevia ammonites are characterized by their distinctive shell morphology. Typically, their shells are involute, meaning that the earlier whorls are completely covered by the later ones. The coiling is often compressed, giving the shell a flattened appearance. A notable feature of Rakoilevia is the presence of strong ribs, which are often bifurcating or branching. These ribs are prominent and can form a raised pattern on the shell surface. The suture lines, which mark the internal divisions of the shell chambers, are generally complex, a characteristic common to many advanced ammonites.

The distribution of Rakoilevia fossils suggests a wide geographic range, with specimens discovered in various parts of the world. Their presence in different rock formations has made them useful index fossils for correlating sedimentary layers from the Jurassic and Cretaceous periods. Paleontologists study Rakoilevia to understand ammonite evolution, paleoecology, and the paleobiogeography of ancient marine environments. The specific ecological niche occupied by Rakoilevia is inferred from the associated fossil assemblages and the morphology of the shells, suggesting they likely inhabited open marine environments. The genus is considered an important component of Mesozoic marine fauna, contributing to the biodiversity of ancient oceans before the Cretaceous-Paleogene extinction event.