Petrobrasia diversicostata Krömmelbein, 1965

Fig. 8, 11a–c

1965b Petrobrasia diversicostata n. sp. —Krömmelbein, p. 65–66, pl. 2, fig. 6.

Diagnosis: A Petrobrasia species with striking sculpture of strong and fine ridges or ribs on both valves: a strong dorsal ridge and a ventral ridge are joined over the posterior margin into a recumbent V; a rather weaker short ridge marks the central valve area; the valve field between the strong ridges shows finer little ridges, which run more or less parallel to the strong ones. Dorsally and ventrally to the “recumbent V” fine ridges run parallel to the relevant valve edges.

Holotype: Carapace, SMF Xe 5382.

Paratypes: Not deposited.

Dimensions: Holotype, length 0.93mm, height 0.50mm, width 0.30mm.