Pithocerithium, Sacco, 1894

Harzhauser, Mathias, Guzhov, Aleksandr & Landau, Bernard, 2025, A revision of the Cainozoic Cerithiidae and Plesiotrochidae (Mollusca: Caenogastropoda) of the Paratethys Sea (Europe, Asia), Zootaxa 5625 (1), pp. 1-180 : 91-92

Pithocerithium ? sp. species inquirenda

Cerithium politioanei elegans n. ssp. — Özsayar 1977: 61, pl. 9, fig. 9 [non Deshayes 1824].

Discussion. Özsayar (1977) described Cerithium politioanei elegans as new subspecies based on a single subadult specimen. The illustration shows a very small, broad shell (SL. 5.8 mm, MD: 4.0 mm) with broad subsutural ramp and prominent angulation with large, rounded tubercles. The name is preoccupied by Deshayes (1824), but we refrain from introducing a replacement name until more material allows a better characterization of this species. A closer relationship to the Sarmatian Cerithium politioanei Jekelius, 1944 [treated herein tentatively as synonym of Pithocerithium rubiginosum ( Eichwald, 1830) ] is excluded based on the much broader shell and the position of the angulation close above the abapical suture.

Özsayar dated the fauna that he collected near Pazar as Volhynian, but some listed and illustrated species are of Konkian age. Therefore, the locality may also expose Konkian beds or Konkian specimens were redeposited in Volhynian strata.

Eastern Paratethys. Late Konkian or Volhynian (Middle Miocene): Turkey: Pazar ( Özsayar 1977).

Genus Ptychocerithium Sacco, 1895

Type species. Cerithium granulinum Bellardi & Michelotti, 1840 ; original designation by Sacco (1895: 23). Late Miocene, Italy.

Diagnosis. “ Size and shape of Vulgocerithium: spire elongated, with almost conical outline; whorls adorned with straight axial ribs, crossed by spiral cords, which form granulations there; last whorl generally lower than one third of the total height, bearing a rather strong varix diametrically opposed to the labrum; base covered by spiral cords, often very prominent, excavated under the neck which is short and thin. Aperture small, oval-rounded, with narrow spiral groove limited by a parietal rib, not very prominent; canal short, strongly narrowed at its origin, little recurved and briefly truncated at its end; labrum with vertical profile, not prominent anteriorly, generally varicose externally, structured internally by the outer lamellae; columella excavated, curved S-shaped along the canal, without pliciform torsion; columellar margin rather thin, narrow, well limited on its basal outline.” ( Cossmann 1906: 80–81, translated from French).

Discussion. The original diagnosis by Sacco (1895: 23) is very brief: “ forms like Cerithium but with more or less pronounced longitudinal ribs [translated from Italian].” Ptychocerithium Sacco, 1895 is characterized by relatively slender conical shells with more or less prominent axial ribs, a prominent parietal denticle and a strong varix on the last whorl placed at about 120–180° from outer lip. The species lack pointed tubercles and a predominant mid-whorl spiral cord, which is typical for many Thericium Monterosato, 1890 species. The type species has a regularly shaped, slender conical spire with convex early teleoconch whorls, which become weakly angulated during later stages of growth. Other Ptychocerithium species lack such angulation. The suture of P. granulinum Bellardi & Michelotti, 1840 is linear due to the absence of varices. Other species included in Ptychocerithium , such as P. taurobronnoides ( Sacco, 1895) , P. turritoplicatum ( Sacco, 1895) , P. bronniforme ( Hilber, 1882) and P. bronnii ( Naumann, 1852) , develop varices also on spire whorls and have an undulating suture.

Stratigraphy. Ptychocerithium appeared during the Rupelian in the Western Tethys with species like P. ighinai ( Michelotti, 1861) and P. plicatoligocenica ( Sacco, 1895) ( Harzhauser 2004) and persisted in the Proto-Mediterranean Sea into the Tortonian and Messinian ( Harzhauser et al. 2013b). Eocene species placed in this genus by Le Renard & Pacaud (1995) and Astibia et al. (2018) are closer to Potamididae genera such as Serratocerithium Vignal, 1897 and should be excluded from Cerithiidae .