Wareniconcha? sp., 2009

Kiel, Steffen, Sami, Marco & Taviani, Marco, 2023, Mollusks (Gastropoda, Bivalvia) from Miocene cold-seep deposits in northern Italy: revisions and additions, European Journal of Taxonomy 910, pp. 115-160 : 146-147

Wareniconcha? sp.

Fig. 12I–J

Material examined

ITALY – Emilia-Romagna • 1 spec.; Castel di Casio ; MGGC 22329 (L = 31.0, H = 26.8, W = 15.8 mm) .

Description

Shell outline roundish-oval, umbo elevated, blunt; anterior margin acutely rounded, ventral margin convex; anterior adductor muscle scar elongate-oval; pallial line crenulate, close and parallel to ventral margin; no pallial sinus, but at its posterior end, the pallial line curves sharply upward and attaches to posterior adductor muscle scar at its anterior side. Shell with fine, radial, internal striations; posterior adductor muscle scar bound anteriorly by weak but distinct posterior ridge.

Remarks

This shell is insufficiently preserved for a confident assignment to Wareniconcha : it lacks the external shell and hence the lunule and escutcheon remain unknown; the posterior margin is broken off; and the hinge dentition cannot be examined. However, overall the shell is very similar to the type species Wareniconcha guineensis (Thiele, 1931) . It certainly is too short and has a too narrow and elongate anterior adductor muscle scar to be an aberrant specimen of Archivesica aharoni Kiel & Taviani, 2017 , or other Italian Miocene species of Archivesica .

Stratigraphic and geographic range

Upper Oligocene (upper Chattian) to Lower Miocene (Aquitanian), northern Italy.

Figures

Fig. 12. Vesicomyid bivalves from Miocene Calcari a Lucina seep deposits in northern Italy. A–H. Archivesica strigarum Kiel & Taviani, 2017.A–B. Articulated specimen from Caselle A (NRM Mo 204841). C. Hinge of RV (Caselle A, NRM Mo 204842). D. Hinge of LV (Caselle A, NRM Mo 204843). E. Articulated specimen from Casola showing ligament (MGGC 22325). F. Articulated specimen from Casola, view on RV showing anterior adductor muscle scar (MGGC 22326). G. Internal mold of RV showing muscle scars and pallial line, from Castillon dei Pepoli (MGGC 22323).H. Left valve with shell remains, from Casola (MGGC 22324). I–J. Wareniconcha? sp., external view on articulated specimen from Castel di Casio (MGGC 22329).