Vasidae, , Abbott, 1950

Vermeij, Geerat J., 2024, Shell-based genus-level reclassification of the Family Vasidae (Mollusca: Neogastropoda), Zootaxa 5405 (4), pp. 526-544 : 527-528

Family Vasidae H. & A. Adams 1853

Diagnosis. Shell medium to large in size, length 25 to 230 mm, usually thick and solid; when fully expressed, sculpture consisting of rounded axial ribs bearing one or more rows of tubercles or spines on upper part of last whorl; basal sculpture consisting of two or more spiral rows of shorter spines of tubercles; upper and basal sets of spines separated by sector with spiral cords, which may be noded or smooth; adult outer lip with crenulated polished edge, its inner side smooth or with variably long spiral lirae; inner lip with three to five symmetrical columellar folds; siphonal canal moderately to very long.

Remarks. The family Vasidae comprises a compact group of Late Eocene to Recent neogastropods with ornate shells. Traditionally the group has often been considered to be a subfamily Vasinae of Turbinellidae , but Lemarcis et al. (2022) showed with molecular evidence that Vasidae and Turbinellidae belong to separate, distantly related clades, which also differ anatomically ( Kantor 1996; Medinskaya et al. 1996). It is therefore appropriate to treat the Vasidae at family level.

The prevailing consensus holds that the Vasidae comprises five genera: Altivasum Hedley, 1914 from temperate Australia, Hystrivasum Olsson & Petit, 1964 from the Pliocene and Pleistocene of Florida, Siphovasum Rehder & Abbott, 1951 from the Gulf of Mexico, Tudivasum Rosenberg & Petit, 1987 from Australia and Zanzibar, and Vasum Röding 1798 from throughout the tropics. The subgenus Globivasum Abbott, 1950 was considered a synonym of a broadly construed Vasum by Vokes (1966).

As in other neogastropods, the shell of Vasidae is divisible into three sectors: an adapical sector, extending from the suture to the last whorl’s periphery; a central sector of the last whorl; and an abapical sector centered on the siphonal canal and adjacent basal portion of the last whorl. ( Vermeij 2002). In the case of Vasidae , the abapical sector comprises the siphonal canal and the two or more spiral rows of basal spines or tubercles on the shell exterior as well as the columellar folds on the adaxial wall of the aperture. The adapical sector is nearly always characterized by one or two rows of spines or tubercles. Between the adapical and abapical sectors, the shell exterior bears spiral cords, which are often marked by small scales or tubercles. There is considerable variation in the relative sizes of the three sectors of the shell.

The presence of basal spines in Vasidae is shared with three other neogastropod groups:the Muricidae (Muricinae, some Coralliophilinae, some Ergalataxinae and Muricopsinae), Melongenidae (especially in the genera Melongena , Echinofulgur , Rexmela , Torquifer , and Tropochasca ), and Columbariidae (especially in Columbarium ). Merle (2001, 2005) showed for Muricidae that these spines are part of a sculptural zone that differs from the more adapical spiral arrangement of cords and tubercles on the last whorl. Although all these families lack columellar folds, Cossmann (1901) and Douvillé (1920, 1921, 1929) inferred a close relationship among Turbinellidae (including Vasinae ) and Melongenidae , implying homology and conservation of the basal spines. Early melongenids such as Cornulina , Sycostoma , and species in the Pugilina clade (with Pugilina , Hemifusus , Saginafusus , and Volegalea ) lack the basal spines even when peripheral tubercles are often expressed in these taxa. This circumstance, together with the fact that early columbariids and turbinellids also lack basal spines, implies that the basal spines in the families under consideration evolved independently from a condition in which basal spiral cords are stronger than those on more adapical sectors of the shell. Such highly expressed basal cords are very widespread among neogastropods including Pseudolividae, Conoidea , Strepsiduridae , Fasciolariidae , Nassariidae , Volutidae , and Mitridae (see Vermeij 1998).

Although columellar folds such as those in Vasidae appear to be topographically linked to external basal spines or cords, the above discussion shows that those external basal features often develop in the absence of columellar folds, and that folds can develop in the absence of basal external sculpture. This independence implies separate genetic and developmental controls on the expression of external and internal sculptural features on the abapical sector of the shell’s last whorl ( Vermeij 2002).

Key to genera of Vasidae

1 Siphonal canal long, narrow, ventrally closed near distal end, axial ribs high and long, spines absent, outer and inner lips flared and forming continuous peristome posteriorly— Siphovasum ; spire high or low, siphonal canal open.................... 2

2 Adult outer lip glazed at edge and on abapertural side........................................................ 3 adult outer lip glazed only at edge........................................................................ 7

3 Umbilicus absent— 6; umbilicus present................................................................... 4

4 Sides of last whorl concave, siphonal canal with dorsally directed tip, posterior end of aperture forming lobe or glazed surface— Rhinovasum gen. nov.; Last whorl not laterally concave, shell often very spiny, spire high............................ 5

5 Aperture narrow, tip of siphonal canal dorsally directed— Florivasum gen. nov.; aperture broad, siphonal canal straight................................................................................................. Altivasum

6 Shell slender with very long straight siphonal canal, inner lip raised at edge— Tudivasum ; shell with siphonal canal short, inner lip narrow and not raised, spines or nodules on all primary spiral cords....................................... Vasum

7 Umbilicus absent— Aristovasum gen. nov.; umbilicus present.................................................. 8

8 Shell spiny or most or all primary spiral cords, three or more rows of basal spines— Hystrivasum ; shell with spines or tubercles only on upper part of last whorl and on base, two basal rows of spines........................................... 9

9 Axial ribs short, spire low— Volutella ; axial ribs long, spire high....................................... Globivasum