Rineceras undefined-1

Rineceras sp. 1

Fig. 4A

MOROCCO • 2 specimens; Anti-Atlas, north of Gara el Itima, 35 km east-northeast of Taouz; basal Hamou-Rhanem Formation; Ebbighausen & Korn 2004 Coll.; MB.C.31293.1–2.

Specimen MB.C.31293.1 is a fragment of about a quarter of a whorl of the body chamber (Fig. 4A); it has a whorl width of 23 mm, which may correspond to a conch diameter of 60 mm. The weakly depressed whorl profile (ww/wh ~1.25) is rounded-trapezoidal with a flattened venter, a broadly rounded ventrolateral shoulder and a broadly rounded umbilical wall. The whorl overlap zone is very small (IZR ~ 0.10).

The fragment shows the well-preserved shell ornament with 14 spiral ridges on each side from the midventer to the umbilical seam; the ridges are irregularly spaced on the venter but almost equally spaced on the ventrolateral margin and umbilical wall. The growth lines, which extend with a deep, rounded V-shaped sinus across the venter, are much finer than the spiral ridges. They are occasionally strengthened to form a conspicuous granulation; at the crossing with the spiral ridges, they form slightly elongate spines.