Noillaniellidae

Noillaniellidae is a family of extinct marine invertebrates belonging to the class Gastropoda, specifically within the subclass Neritimorpha. These fossils are found in rocks dating primarily to the Mesozoic Era, with most occurrences in the Jurassic and Cretaceous periods. The shells of Noillaniellidae are typically small to medium-sized, characterized by a low, conical spire and a wide aperture. A distinguishing feature is often the presence of prominent axial ribs and sometimes spiral ornamentation. The aperture is generally rounded or ovate, and the columella is usually smooth and thickened.

Fossils of this family have been discovered in various marine environments worldwide, suggesting a relatively widespread distribution during the Mesozoic. Their ecological role is not fully understood, but like other neritimorph gastropods, they likely inhabited shallow to moderate marine waters, possibly grazing on algae or detritus. The taxonomy of Noillaniellidae has been subject to revision as new specimens and analytical techniques become available. They are often found in association with other common Mesozoic marine fossils, such as ammonites and bivalves. The precise phylogenetic relationships of Noillaniellidae within Neritimorpha are still a subject of ongoing research, with their evolutionary history offering insights into the diversification of marine gastropods during a pivotal period in Earth's history.