ampullinids

Ampullinids are an extinct family of marine gastropods known from the fossil record. They are part of the caenogastropod lineage and have historically been placed within the superfamily Ampullinoidea. The group appears in Cretaceous deposits and continues into the Paleogene, with fossil finds reported from Europe, Asia, Africa, and the Americas, indicating a broad geographic distribution in ancient seas.

Morphologically, ampullinid shells are typically globose to turbinate, with a relatively low spire and a well-defined aperture. The outer lip is often thick, and the sculpture ranges from smooth to ornamented with spiral or axial elements. Body whorls are frequently inflated, and many species exhibit a pronounced, rounded whorl profile. The diversity of shell forms reflects variations in habitat and evolutionary history within the family.

Ecologically, ampullinids were marine snails that inhabited shallow to moderately deeper shelf environments. They were likely detritivores or grazers feeding on biofilms and microscopic organisms on stones or among seagrass and algal communities. Their morphology suggests adaptations to a variety of soft-substrate to reef-associated settings.

Taxonomic history has been fluid, with ampullinids moved among different subgroups by successive revisions of gastropod classification. They are mainly recognised today as a distinct fossil family, though exact higher-level placement can vary among taxonomic schemes. Continued study of their shell morphology and stratigraphic distribution helps clarify caenogastropod evolution during the Cretaceous–Paleogene interval.

Fossil records of ampullinids contribute to understandings of ancient marine biogeography and the diversification of early caenogastropods. Genera within the family include Ampullina and related forms described from multiple continents.