Ctulosteina

Ctulosteina is a genus of extinct cartilaginous fish that lived during the Late Cretaceous period. These ancient sharks are primarily known from fossilized teeth and dermal denticles discovered in various locations, including North America and Europe. The genus name itself is derived from a combination of "Ctulhu," a cosmic entity from H.P. Lovecraft's fiction, and "steina," a suffix often used in scientific nomenclature. This naming convention, while evocative, does not reflect any direct biological relationship to the fictional entity.

The teeth of Ctulosteina are typically small and triangular, with a smooth or finely striated surface. Their morphology suggests a diet consisting of small invertebrates, such as crustaceans and mollusks, which they likely crushed with their jaws. The dermal denticles, tiny tooth-like structures that cover the skin of sharks, further aid in reconstructing the appearance and ecological role of Ctulosteina. They were likely relatively small to medium-sized sharks, inhabiting shallow marine environments. Research into Ctulosteina continues to shed light on the diversity and evolution of sharks during the Mesozoic Era, a period of significant change for marine ecosystems.