lenticulinids

Lenticulinids are a group of extinct marine microorganisms belonging to the Foraminifera. These single-celled organisms, also known as foraminiferans, are characterized by their shells, or tests, which are typically composed of calcite. The name "lenticulinid" refers to the lens-shaped or lenticular form of their tests, although this is not a universal characteristic of all species within the group. Lenticulinids are particularly known for their coiled or planispiral test architecture, where chambers are added in a spiral, often in a single plane.

Fossils of lenticulinids are found predominantly in marine sedimentary rocks, especially from the Mesozoic and Cenozoic eras. Their abundance and distinctive morphologies make them valuable index fossils for biostratigraphy, aiding in the dating and correlation of rock layers. These microorganisms played a role in ancient marine ecosystems, likely as planktonic or benthic organisms that fed on detritus or smaller plankton. Their evolutionary history is intertwined with that of other foraminiferal groups, and their study contributes to understanding past ocean conditions and the evolution of marine life. Research on lenticulinids often involves micropaleontology and paleoceanography.