Abichites alibashiensis

Description Specimen MB. C. 30051 has 62 mm conch diameter and is rather well preserved with about 190 degrees of the body chamber visible (Fig. 57 A). The whorl profile of the terminal body chamber has a broadly rounded umbilical margin, weakly concave flanks that are gently converging towards the flat venter, which is deliminated by an angular ventrolateral shoulder. In the phragmocone, the whorl profile is oval with a broadly rounded venter. The change of the sculpture from the subadult stage with coarse ventrolateral nodes (12 per volution) towards the adult stage with only weak ribs on the flank happens already before the beginning of the terminal body chamber. Specimen MB. C. 30046 is smaller (48 mm dm) and shows the transformation from the subadult stage with rounded ventrolateral margin to the adult stage with quadrate whorl profile, in which the venter is flat and separated from the flanks by an angular margin (Fig. 57 B). The sculpture of the subadult stage possesses prominent ribs (about 13 per volution), which weaken out on the terminal body chamber. The suture line of specimen MB. C. 30046 shows a simply subdivided external lobe with narrow, V-shaped prongs, a broadly rounded parabolic ventrolateral saddle and asymmetric, weakly serrated adventive and lateral lobes (Fig. 57 D).