Conilithes striatulus ( Brocchi, 1814 )

Psarras, Christos, Koskeridou, Efterpi & Merle, Didier, 2021, Late Miocene Conidae (Mollusca: Gastropoda) of Crete (Greece). Part 1: genera Conilithes Swainson, 1840 and Conus (Kalloconus) da Motta, 1991, Geodiversitas 43 (24), pp. 1309-1339 : 1319-1320

Conilithes striatulus ( Brocchi, 1814)

( Figs 9 , 10 ; Table 4)

Conus striatulus Brocchi, 1814: 294 , pl. 3, fig. 4.

Conus (Chelyconus) striatulus – Sacco 1893a: 93-96, pl. 9, figs 30- 31, 34. — Muñiz Solís 1999: 61-63, fig. 8I-J.

Conus striatulus – Pinna & Spezia (1978): 137, pl. 22, fig. 2-2.

TYPE LOCALITY. — Piacentino Piemontese , Italy. Pliocene. TYPE MATERIAL. — Lectotype figured in Brocchi (1814: pl. 3, fig. 4). Fixation of the lectotype ( MSNM i4672, Brocchi coll.) by inference of “holotype” (ICZN 1999: art. 74.6) by Pinna & Spezia (1978). STRATIGRAPHIC RANGE. — Early Miocene: Burdigalian of Italy (Colli Torinesi; Sacco 1893a); late Miocene: Tortonian of Italy (Stazzano; Sacco 1893a) and Greece (Messara Basin, Crete); Pliocene: Piacenzian of Italy (Piacentino; Sacco 1893a) and Spain (Estepona; Muñiz Solís 1999). MATERIAL EXAMINED. — Greece. Psalidha, one specimen MNHN.F. A72601 . Panassos: five specimens AMPG(IV) 2639-2643 . Crete: seven specimens MNHN.F. A72594 to MNHN.F. A72600 . All of them display colour patterns under UV light.

SHELL DESCRIPTION

Small-sized shells with spire whorls of relatively medium height and robust outline. Spire whorls straight to coeloconoid, conical, with scalariform, slightly elevated spire whorls and angulated shoulders. Usual, faint spiral cords on early spire whorls, but no tubercles or beads. Subsutural flexure moderately deep, strongly curved, moderately asymmetrical. Maximum diameter on shoulder. Last whorl straight, conical. Aperture straight. Fasciole indistinct. Spiral grooves on the anterior part of last whorl.

COLOUR PATTERN VARIATION. — The colour pattern consists of fluorescent flammulae on the spire ( Fig. 10 ). The last whorl bears a primary pattern of irregular, fluorescent blotches. The blotches can be axial flammulae that continue from the spire whorls, towards the anterior of the shell, or can be spirally arranged as bands, parallel to a second pattern of fluorescent spiral lines of dots and dashes, along the length of the shell. The spiral rows of dots or dashes start at carina and continue along the length of shell. All patterns are occasionally disrupted by non-fluorescent blotches ( Fig. 10 ). On some shells, a non-fluorescent band exists along the centre of the length of the shell, decorated with fluorescent spiral lines of dots or dashes ( Fig. 10 , non-fluorescent band).

REMARKS

This species has been reported from the Miocene (Burdigalian and Tortonian) and the Pliocene of Italy (see Brocchi 1814: pl. 3, fig. 4; Sacco 1893a: pl. 9, fig. 30). The Greek material ( Table 4) is very similar to the lectotype of Conus striatulus (MSNM i4672) coming from the Pliocene. Unfortunately, no colour pattern under UV light is visible on the lectotype (Giorgio Teruzzi, personal communication). Nevertheless, we do not observe any shell differences between the Greek specimens and the lectotype. Therefore, we consider them to belong to Conilithes striatulus . This species slightly differs from the other Conilithes species by its the shorter spire whorls and its more robust shell.

Figures

FIG. 9. — Conilithes striatulus (Brocchi, 1814) from Tortonian of Crete (Greece). Specimens shown in apertural, abapertural, and apical views under natural and UV light: A, AMPG(IV) 2640, Panassos; B, AMPG(IV) 2641, Panassos; C, MNHN.F.A72597, Crete; D, MNHN.F.A72601, Psalidha; E, AMPG(IV) 2643, Panassos; F, AMPG(IV) 2639, Panassos; G, MNHN.F.A72600, Crete; H, specimen MNHN.F.A72599, Crete; I, AMPG(IV) 2642, Panassos. Scale bar: 1 cm.

FIG. 10. — Elements constituting the colour pattern of Conilithes striatulus (Brocchi, 1814), AMPG(IV) 2640, Panassos, Crete, Greece. Same specimen as in the Fig. 9A. Scale bar: 0.2 cm.