Ellenstrongia, Amati & Giulio & Oliverio, 2023

Amati, Bruno, Giulio, Andrea Di & Oliverio, Marco, 2023, Shallow-water Rissoidae of the genera Alvania Risso 1826 Haurakia Iredale 1915 Parashiela Laseron 1956 Simulamerelina Ponder 1985 and Subestea Cotton 1944 Gastropoda Caenogastropoda Rissooidea from French Polynesia with the description of a new deep-water genus, Zoosystema 45 (25), pp. 803-892 : 828

Genus Ellenstrongia n. gen.

urn:lsid:zoobank.org:act:4E99EFB1-B5EF-4109-BE9F-55A1D328

TYPE SPECIES. — Ellenstrongia tarasoc n. gen., n. sp.

DIAGNOSIS. — Shell of medium (height> 4 mm) size for the family, robust, slender and acute, with very convex whorls and deep sutures; protoconch multispiral, coloured, strongly sculptured; teleoconch with weak spiral sculpture and narrow, acute, orthocline and flexuose axial ribs; microsculpture of minute pits; umbilical fissure absent; aperture piriform, peristome continuos, wide with rather thick outer varix, sharp outer lip, internally smooth; colouration uniform white with light orange protoconch.

Operculum and soft parts not examined.

ETYMOLOGY. — The name of the new genus is after Ellen E. Strong (USNM), for her contribution to the knowledge of gastropod systematics and evolution. She has shared her unpublished molecular data, supporting the classification of the new genus in the Rissoidae .

REMARKS

The new genus is proposed for a species with a unique combination of characters, not shared with any known genus of Rissoidae . Initially, we considered also the hypothesis that it was not a rissoid, but then Ellen E. Strong (pers. comm.) communicated that her still unpublished molecular data confirmed it was nested inside Rissoidae .

Shell morphology, i.e., the elongated shell with acute spire, convex whorls, double sculpture on the teleoconch (the axial one stronger), may recall some European species of Alvania , such as A. rudis (Philippi, 1844) , A. micalii Chirli, 2006 , and A. merlei Van Dingenen, Ceulemans & Landau, 2016 . However, the sculpture of the multispiral protoconch is completely different, as is also diagnostic the peculiar pitted microsculpture.

A similar teleoconch microsculpture is observed in the genus Porosalvania Gofas, 2007 known from northeast Atlantic Seamounts ( Gofas 2007: 848). Known species of Porosalvania all have a nearly smooth, paucispiral, dome-shaped protoconch: the corresponding part of the multispiral protoconch of Ellenstrongia n. gen. (the protoconch I) is more protruding and densely and strongly sculptured by microgranules; additionally, the outline of Porosalvania is neatly more scalariform. Relationships among the rissoid genera with pitted teleoconch microsculpture (e.g. Gofasia Bouchet & Warén, 1994 , Manzonia Brusina, 1870 , Onoba H. Adams & A. Adams, 1852 , Porosalvania Gofas, 2007 ) should be tested by integrating molecular data. This feature is also present in genera of other rissooidean families (e.g. Barleeia W. Clark, 1843 , Rissoina d’Orbigny, 1841 ).

The markedly sculptured and coloured multispiral protoconch of Ellenstrongia n. gen. is very similar to that of some species of Benthonellania Lozouet, 1990 (e.g. B. alvanioides Oliver & Rolán, 2017 , B. bouteti Amati, Di Giulio & Oliverio, 2022 and B. tuamotu Amati, Di Giulio & Oliverio, 2022 ) ( Amati et al. 2022). The new genus, however, differs in the more slender teleoconch profile with more convex whorls, and the peculiar pitted microsculpture.