Altivasum Hedley, 1914

Vermeij, Geerat J., 2024, Shell-based genus-level reclassification of the Family Vasidae (Mollusca: Neogastropoda), Zootaxa 5405 (4), pp. 526-544 : 528

Genus Altivasum Hedley, 1914

Type species. Altivasum flindersi Verco, 1914 ; by original designation, Recent , Australia

Diagnosis. Shell large, up to a length of 230 um, relatively light-weight, spire high; axial sculpture consisting of relatively short, high ribs; all primary spiral cords adorned with scales, tubercles, or spines, including three cords above shoulder angulation; scales and spines adaperturally oriented; basal rows of spines not well differentiated from more adapical spines; umbilicus wide; outer lip glazed at edge and abaperturally, forming broad glazed area at posterior end of aperture; inner side of outer lip smooth; aperture relatively broad; columella with three folds; siphonal canal long, very narrowly open, straight.

Included species. Altivasum flindersi Hedley, 2014 (Great Australian Bight), A. clarksoni Maxwell & Dekkers, 2019 (off Esperance, Western Australia), A. hedleyi Maxwell & Dekkers, 2019 (eastern Great Australian Bight), to Geraldton, Western Australia), A. pauladellaboscae Cooper & Maxwell, 2020 (Jurien Bay to Rockingham, Western Australia), A. profundum Dekkers & Maxwell, 2018 (off Augusta, Western Australia).

Material examined. A. flindersi, BMNH, Coffin Bay , South Australia ; BMNH Port Lincoln , South Australia . A. hedleyi, BMNH Safety Bay , Western Australia; Vermeij collection Augusta, Western Australia .

Remarks. Altivasum is a distinctive genus from temperate southern and western Australia. Its composition and characters have been reviewed by Dekkers & Maxwell (2018), Maxwell & Dekkers (2019), and Cooper & Maxwell (2020). At a maximum length of 230 mm, A. hedleyi is the largest known vasid. The broadly open umbilicus, reflected outer lip, adaperturally oriented scales or spines, smooth inner side of the outer lip, and long straight siphonal canal s et altivasum apart from other genera. Nothing has been published on the biology of any of the species.