Cancilla sismondai ( Michelotti, 1847 )

Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4983 (3), pp. 1-72 : 59

Cancilla sismondai ( Michelotti, 1847)

Figs 15B 1 –B 2

* Mitra Sismondai Mihi. — Michelotti 1847: 317.

Mitra striato-sulcata Bell. — Bellardi 1850: 15, pl. 2, fig. 4.

Cancilla striato sulcata Bell. —Hoernes 1880: 125.

Mitra (Cancilla) striato-sulcata Bell. — Hoernes & Auinger 1880: 81, pl. 9, figs 21a–c.

Mitra Sismondae Michtti. — Bellardi 1887a: 31, pl. 1, fig. 30.

Mitra Sismondae Micht. var. subdepressiuscula Sacc. — Sacco 1904: 81, pl. 18, figs 19–20.

Mitra Sismondae Micht. var. striosulculata Sacc. — Sacco 1904: 81, pl. 18, fig. 21.

Mitra Sismondae Micht. var. pseudobourguetana Sacc. — Sacco 1904: 81, pl. 18, fig. 22.

Mitra Sismondae Micht. var. persulcatomagna Sacc. — Sacco 1904: 81, pl. 18, fig. 23.

Mitra (Tiara) sismondae Michelotti. — Robba 1968: 562, pl. 43, figs 2a–b.

Cancilla sismondae ( Michelotti, 1847) — Davoli 2000: 190, pl. 6, figs 19–22.

? Mitra (Tiara) sismondae Michelotti — Pelosio 1967: 148, pl. 43, figs 1a–b, 2, 13.

? Cancilla sismondai Michelotti, 1847 — Cavallo & Repetto 1992: 120, fig. 305.

non Mitra (Tiara) sismondai Michelotti, 1847 — Janssen 1972: 41, pl. 7, fig. 7.

Type material. Syntype or holotype described by Michelotti (1847), Tortona region, Italy; late Miocene, Tortonian. The specimen might have been stored in the collections of the Dipartimento di Scienze della Terra, Sapienza Università di Roma, but parts of the Michelotti collection were destroyed during World War II ( Manni 2005).

Additional material. NHMW 1865/0001/0171, SL: 46.7 mm, MD: 16.4 mm, Lăpugiu de Sus ( Romania), il- lustrated in Hoernes & Auinger (1880, figs 21a–c), figs 15B 1 –B 2.

Revised description (based on Paratethyan material). Shell moderately large and slender, biconical fusiform, with weakly convex spire whorls and impressed suture. Protoconch and early teleoconch whorls unknown. About six broad spiral cords on early teleoconch whorls, separated by narrow spiral grooves. Spiral cords subsequently bifurcated by secondary and tertiary spiral grooves on penultimate and last whorls. Axial sculpture reduced to faint growth lines causing slight irregularity of spiral cords. Last whorl evenly convex, periphery at adapical tip of aperture, slowly contracting. Aperture narrow, abapically contracting. Columellar callus sharply delimited. Columella with four prominent columellar folds, weakening abapically. Siphonal canal moderately long, narrow, straight, with shallow siphonal notch.

Shell measurements and ratios. SL = 46.7 mm, MD: 16.4 mm; AA = 37°, SL/ MD: 3.1, AL/AW: 6.6, AH/S: 2.1.

Discussion. Cancilla sismondai ( Michelotti, 1847) is recorded from the middle Miocene (Badenian) of the Central Paratethys Sea and the late Miocene (Tortonian) of the Proto-Mediterranean Sea. Occurrences from the early Pliocene of the Mediterranean Sea, described by Pelosio (1967), seem to represent a separate species, characterised by a larger, more elongate shell and a more delicate and uniform spiral sculpture. Similarly, the specimen from the Miocene of the North Sea Basin, described by Janssen (1972) as Mitra sismondai , is most probably not conspecific. It differs from Cancilla sismondai in its straight-sided spire whorls and regular spiral sculpture of equally size spiral cords.

A minute specimen from the middle Miocene of Korytnica ( Poland), described by Bałuk (1997, pl. 10, fig. 8) in open nomenclature, was discussed as potential Cancilla sismondai by Davoli (2000: 190). The stout shell and its prominent spiral sculpture, however, differ clearly from C. sismondai at same growth stage.

Michelotti (1847) named this species explicitly after the Italian palaeontologist Eugenio Sismonda (1815– 1870). Therefore, the feminine ending “ sismondae ”, used by Bellardi (1887a), Sacco (1904), Pelosio (1967), Robba (1968) and Davoli (2000), is an incorrect emendation.

Palaeoenvironment. Unknown.

Distribution in Central Paratethys. Badenian (middle Miocene): Făget Basin: Lăpugiu de Sus ( Romania) ( Hoernes & Auinger 1880).

Proto-Mediterranean Sea. Tortonian (Llate Miocene): Po Basin: Tortona region, Stazzano, Sant Agata, Montegibbio ( Italy) ( Davoli 2000).