Ancilla thomassini is a species of sea snail, a marine gastropod mollusk in the family Ancillariidae, the olives and the likes.
Distribution This marine species occurs off Madagascar.
References
Kilburn R.N. (1981). Revision of the genus Ancilla Lamarck, 1799 (Mollusca: Olividae: Ancillinae). Annals of the Natal Museum. 24(2): 349–463.