†Plesiothyreus ancyliformis Grateloup 1828 (snail)
Gastropoda - Neritoidea - Phenacolepadidae
Alternative combinations: Capulus ancyliformis, Pileopsis ancyliformis
Belongs to Plesiothyreus according to P. Lozouet et al. 2001
Sister taxon: Plesiothyreus parmophoroides
Ecology: epifaunal omnivore