Praerosaria sp., Thivaiou, Harzhauser & Koskeridou, 2019

Thivaiou, Danae, Harzhauser, Mathias & Koskeridou, Efterpi, 2019, Early Miocene Gastropods from the Felli Section (Proto-Mediterranean Sea NW Greece), Geodiversitas 41 (8), pp. 323-366 : 341

? Praerosaria sp .

( Fig. 10 A-H)

MATERIAL EXAMINED. — Sample F11: AMPG (IV) 2460 (one specimen).

DIMENSIONS. — Length:17.00 mm; height: 8.50 mm; width: 10.50 mm.

DISTRIBUTION. — Early Miocene. Proto-Mediterranean Sea: Greece (this paper).

DESCRIPTION

Shell small, solid, pyriform, posteriorly swollen. 18 closely spaced columellar teeth, 22 closely spaced labral teeth, fossula convex, smooth with 4 faint columellar teeth apically; terminal fold moderately developed. Venter smooth, convex; outer lip smooth convex. Anterior marginated on both left and right profiles. Left profile rounded; right profile angled from anterior to posterior margins. Posterior edge with callus and with marginated, less inflated in profile. Aperture moderately sigmoidal, narrow slightly widening anteriorly. Siphonal canal wider than anal canal.

Preserved colour pattern consists of two series of faded punctuations; posteriorly a more distinct disc is present.

REMARKS

This species is most likely represented by two more specimens that are poorly preserved, broken and deformed. The generic assignment is uncertain since the intra-specific morphological variation cannot be assessed.

Apical and adapical margins, narrow aperture with small teeth, convex-inflated ventral and outer lip and distinguishable line on the right profile seem to be the key characters shared by all of the species of Praerosaria as pictured by Dolin & Lozouet (2004).

Most of the species of the then new genus Praerosaria described by Dolin & Lozouet (2004) are of similar dimensions to the Greek specimen. Morphologically, the present species is close to the type species of the genus, P. exflaveola (Sacco, 1894), by having marginated edges, a similar terminal fold, and almost the same number of closely-spaced teeth. Another similar species form the Chattian of the Aquitaine Basin (SW France) is P. charlenae Dolin & Lozouet, 2004 which has slightly more prominent columellar denticles and a less inflated shell dorsally. Indeed, all of the species of Praerosaria seem to be uniform in shell characters, presenting variations that mainly affect the number of columellar and labial denticles and width of the outer lip.

Figures

FIG. 10. —?Praerosaria sp.: A-H, AMPG(IV) 2460; G, AMPG(IV) 2460, under UV light. Scale bars: 5 mm.