Hystrivasum horridum, common name the rough or shaggy vase, is a fossil species of medium-sized predatory gastropod in the family Turbinellidae.

Like other species in the subfamily Vasinae, Hystrivasum horridum shells are large, thick and heavy.

Hystrivasum horridum, formerly Vasum horridum, belongs to an extinct group that is easily distinguished from modern Vasum by the presence of two sets of spines or nodes located on the shoulder of the whorls.

H. horridum has 12-15 wide, scoop-like spines that project almost horizontally from the shoulder.

The famous malacologist William Healey Dall stated that this "magnificent species seems to be confined to [the Pliocene Caloosahatchie Beds] and to have given rise to no descendant in the recent fauna.”[3]