Granulatocincta, Harzhauser & Landau & Janssen, 2022

Harzhauser, Mathias, Landau, Bernard & Janssen, Ronald, 2022, The Clavatulidae (Gastropoda, Conoidea) of the Miocene Paratethys Sea with considerations on fossil and extant Clavatulidae genera, Zootaxa 5123 (1), pp. 1-172 : 139

Genus Scaevatula Gofas, 1990

Type species. Scaevatula pellisserpentis Gofas, 1990 . Present-day , São Tomé (Gulf of Guinea) .

Diagnosis. Small, moderately slender fusiform sinistral or dextral shells with high spire and low last whorl. Narrow subsutural collar with beads; entire shells with dense sculpture of axial ribs and spiral cords. Base slowly contracting. Siphonal canal short, relatively wide, deflected to the left. Aperture ovoid with thin and smooth outer lip. Columellar and parietal callus forming rim. Low, dome shaped, paucispiral protoconch with broad axial ribs.

Discussion. The genus was based by Gofas (1990) on a sinistral species from São Tomé (Gulf of Guinea). Later, Rolán & Fernandes (1993) described a second species from the same region as Scaevatula amancioi , which is dextrally coiled.The peculiar sculpture and especially the protoconch sculpture, which is unique within Clavatulidae , strongly suggest that both species belong to the same genus, despite the opposite coiling. Little information is available on the ecology of this genus, which occurs in few meters water depth ( Rolán & Fernandes 1993). Both extant species range around 6 to 8 mm in height and thus are much smaller than the Paratethyan Scaevatula sidoniae ( Hoernes & Auinger, 1891) , which attains 24.8 mm in height. Moreover, the Miocene species is more solid and bears inner lirae, which are unknown from extant Scaevatula . The sculpture of Scaevatula amancioi , in contrast, is very similar to that of S. sidoniae and both develop a bipartite sculpture of early teleoconch whorls. Finally, the sculptured protoconch is so unusual in Clavatulidae that we provisionally place the Miocene species in Scaevatula . Scaevatula sidoniae is slightly reminiscent of Granulatocincta nov. gen. concerning its sculpture, but differs in its bipartite early teleoconch sculpture.

Paleoenvironment. Coastal inner neritic environments ( Gofas 1990).

Distribution and stratigraphy. Scaevatula was known so far only from the modern fauna of tropical West Africa. Our Miocene record from the Paratethyan Sea is the first fossil record of the genus and an additional proof of a faunistic relation between the tropical Eastern Atlantic and the Paratethys Sea, which is documented also for Clavatula and Perrona .