Austromitra lacertosa is an extinct species of sea snail, a marine gastropod mollusk in the family Costellariidae.[1]
Main characteristics: The fusiform shell is costated, abruptly contracted to a beak. The whorls are subangulated medially, without spiral ornament.
The shell is turriculate, ending in a relatively large pullus of two smooth convex whorls, the top laterally immersed.
The four and a half whorls, excluding protoconch, are medially subangulated and ornamented with slightly bent angular ribs, which are subtuberculated on the spiral keel and at each suture (15 on the penultimate whorl). The interspaces are faintly striated transversely. The body whorl is oblong, abruptly attenuated to a short, broad, reverted beak, which is spirally ridged; flatly rounded at the suture, ornamented with acute ribs, a slightly tuberculate antesutural keel, and two approximate tubercular ridges in an alignment with posterior angle of the aperture. The outer lip is thin, roundly insinuated at the suture and internally lirate. The columella shows four stout approximate plaits.[2]
Fossils of this marine species were found in Miocene strata in Victoria, Australia.