foraminiferidit

Foraminiferidit is a genus of benthic foraminifera that first appears in the late Cretaceous and is widely represented through the Paleogene in marine sedimentary deposits. Members of this genus are characterized by a calcareous test composed of a multilobate chamber arrangement with a distinct microstructure of concentric lamellae. The test wall is typically porcelaneous and displays a low to moderate degree of perforation. The aperture is a sharp, slit‑like opening that facilitates the extrusion of the cytoplasmic pseudopodia for feeding and locomotion. Paleoecological data suggest that Foraminiferidit inhabited relatively shallow, warm, oligotrophic to mesotrophic marine environments, often associated with carbonate platforms and reef flats.

Molecular phylogenetic studies, although limited by the rarity of recoverable DNA from fossil specimens, place Foraminiferidit within the order Rotaliida, closely allied to the families Acarinidae and Cylindroperidinidae. The genus is divided into several species, of which Foraminiferidit elegans and Foraminiferidit caesarius are most frequently cited in stratigraphic correlation literature. Stratigraphically, the presence of Foraminiferidit assemblages is used to identify and correlate boundary horizons between the Campanian and Maastrichtian stages. Their distinctive biostratigraphic signals aid in reconstructing paleoenvironmental conditions, indicating periods of relative sea level rise and relative stability in carbonate sedimentation.

Because of their widespread occurrence and the high preservation potential of their calcium carbonate tests, Foraminiferidit fossils serve as valuable proxies for late Cretaceous to early Paleogene paleoceanographic studies, providing insights into ancient climate fluctuations and biogeographic affinities across the western Atlantic sector.