Neopilina

Neopilina is a genus of monoplacophoran mollusks, a small group of deep-sea mollusks with a single cap-shaped shell. Belonging to the phylum Mollusca and the class Monoplacophora, Neopilina comprises several living species found in the Pacific Ocean.

The genus gained prominence after the 1952 discovery of Neopilina galatheae off the Galápagos Islands, the first living monoplacophoran described. The specimens revealed serial repetition of internal organs and musculature along the body, a pattern reminiscent of segmented organisms and important for understanding molluscan evolution.

Neopilina species have a low-profile, cap-like shell covering a broad mantle, a foot used for locomotion, and a mantle cavity containing gills. The arrangement of repeated organ systems along the body is a hallmark of monoplacophorans and has been cited as evidence for ancient segmentation in mollusks.

They inhabit deep-sea environments, often at substantial depths in the Pacific. They are slow-moving benthic detritivores or grazers, feeding with a radula. Detailed life histories are poorly known due to sampling challenges in deep waters.

Taxonomically, Neopilina is placed within Monoplacophora; the class represents a once-diverse Paleozoic lineage with only a few living representatives. Ongoing study of Neopilina and related taxa informs debates about molluscan evolution, development, and the origins of segmentation.