Epitoniidae, Berry, 1910

Webster, Nicole B & Vermeij, Geerat J, 2017, The varix: evolution, distribution, and phylogenetic clumping of a repeated gastropod innovation, Zoological Journal of the Linnean Society 180 (4), pp. 732-754 : 739

Epitoniidae

The state of varices in this family, which originated in the Cretaceous, is complicated. Most species have a number of axial elements on each whorl that generally align from one whorl to the next. These vary from striations to alate lamellae, which we do not consider to be varices ( Fig. 3E ). In most cases, we determined these to be ribs or axial lamellae; however, some species, like many Cirsotrema , Epitonium , Opalia , and Amaea have distinct rounded varices interspersed with the other ribs, the earliest being from the Paleocene ( Abbott, 1974; Kilburn, 1985; Lozouet et al., 2001) ( Fig. 2C ). These varices are not synchronized, and whether they represent growth stoppages is unknown.

Figures

Figure 2. Examples of varices. (A) Ellobiidae: Pythia scarabaeus (L., 1758), lateral view. (B) Ellobiidae: Ellobium aurisjudae (L., 1758), dorsal view. (C) Epitoniidae: Cirsotrema varicosum (L., 1822) JVM3131, lateral view. (D) Eulimidae: Melanella martinii (A. Adams in Sowerby, 1854) JVM1093, apical view; (D’) Lateral view. (E) Batillariidae: Pyrazus ebeninus (Bruguière, 1792), oblique apical view. (F) Cerithiidae: Cerithium eburneum Bruguière, 1792, JVM1132, apical view. (G) Potamididae: Cerithideopsis californica (Haldeman, 1840), apical view. (H) Strombidae: Laevistrombus canarium (L., 1758), O365(D-58), apertural view. (I) Cassidae: Phalium areola (L., 1758), JVM851, apical view. (J) Bursidae: Crossata ventricosa (Broderip, 1833), apertural view, arrowhead; hollow varix. (K) Pseudomelatomidae: Imaclava sp., apertural view. (L) Drilliidae: Imaclava pilsbryi Bartsch, 1950, JVM3053, lateral view. (M) Muricinae: Chicoreus nobilis Shikama, 1977, apertural view. (N) Aspellinae: Aspella pyramidalis (Broderip, 1833), JVM1488, apical view. (N’) Dorsal view. (O) Typhinae: Haustellotyphis cumingii (Broderip, 1833), JVM1362, apertural view. (P) Ocenebrinae: Eupleura nitida (Broderip, 1833), JVM1504, apertural view. (Q) Colubrariidae: Colubraria tortuosis (Reeve, 1844), apertural view. (R) Columbellidae: Strombina fusinoidea Dall, 1916, JVM1634, apical view. (S) Photinae: Phos senticosus (L., 1758), JVM1676, dorsal view. (T) Cancellariidae: Bivetiella cancellata (Linnaeus, 1767), JVM2879, apertural view. Scale bars: 5 mm; arrows indicate one (not all visible) varix. JVM and O represent the University of Alberta collection specimen numbers, specimens without collection numbers come from the Vermeij collection.

Figure 3. Varix-like sculpture not considered to be a true varix. (A) Ergalataxinae: Tenguella granulata (Duclos, 1832) dorsal view, with scar-like rib (arrow). (A’) Apertural view, showing previous apertural teeth associated with scar-like rib (arrow). (B) Vasum turbinellus (L., 1758), dorsal view. (C) Trophoninae: Nipponotrophon stuarti (E. A. Smith, 1880), lateral view. (D) Harpidae: Harpa amouretta Röding, 1798, apical view. (D’) Dorsal view. (E) Epitoniidae: Epitonium scalare (L., 1758), JVM3118, apertural view. (F) Muricopsinae: Homalocantha anatomica (Perry, 1811), apertural view. Scale bars: 5 mm. JVM and O represent the University of Alberta collection specimen numbers, specimens without collection numbers come from the Vermeij collection.