clade Hypsogastropoda Antarctoneptunea benthicola is a species of small-to-medium-sized predatory sea snail or whelk, a marine gastropod mollusc in the family Austrosiphonidae.

[3][1][4] Antarctoneptunea benthicola is a small-to-medium-sized species of marine snail in the genus Antarctoneptunea, the shell reaches 100 mm in height and 40 mm in diameter.

[2] A. benthicola also has a Pleistocene fossil record in the South Island.

[6] The species was formerly recognised as Penion benthicolus,[2][5][6] but evolutionary trees based on mitochondrial and nuclear ribosomal DNA sequence data, as well as geometric morphometric analysis of shell shape and size, indicate that the species belongs to Antarctoneptunea.

[1][7] A subspecies, Penion benthicolus delli Powell, 1971 was formerly recognized,[5] but this taxon has since been demonstrated to be indistinguishable from other P. benthicolus based on shell morphology.