Conus cf. taurinensis

Conus cf. taurinensis (Psarras, Merle & Koskeridou, 2022)

Shell description

Usually small to rarely medium-sized shells (SL max.: 52.5 mm) (Fig. 22). Spire elevated, conical. Outline of spire whorls variable in shape, with height, ranging from medium to high (Fig. 22). Early spire whorls elevated, convex, striate, creating straight to highly conical outline, tuberculated, with faint spiral cords on early sutural ramps. Later spire whorls smooth, elongate, convex, not always in symmetry to surrounding spire whorls, with late spire whorls usually inflated and more robust. Suture incised, slightly undulated. Subsutural flexure shallow, moderately curved, moderately asymmetrical (Fig. 40K). Shoulder smooth to weakly angular, with maximum diameter just below shoulder. Last whorl elongated, curved. Aperture narrow, widening slightly towards fasciole. Siphonal canal short, straight. Siphonal fasciole indistinct. Faint spiral grooves visible on one fifth anterior part of body ⁽¹⁾.

Description of colour pattern

The colour pattern consists of two levels of colouration. The first one is a pattern of irregular blotches (Fig. 23) of variable size, sometimes with zig-zag boundaries (Fig. 22B) or non-continuous spiral bands on the middle and anterior parts of the shell (Fig. 22C, F, H). The pattern might continue on spire whorls as irregular, thin, flammulated blotches (Fig. 24). The second level consists of evenly arranged, spiral rows of wavy dashes and dots (Figs 23–24). The spiral rows start at the shoulder of the shell, continuing spirally towards the anterior part. The spiral rows exists in between the spiral grooves. On some specimens of exceptional preservation, the spiral lines of dashes and dots are better displayed as continuous fluorescent wavy lines, with interruptions of grey coloured oval dots (Fig. 24). These dots are visible even under natural light (Figs 21A, C, 23). When the lines cover the first pattern of irregular blotches, the second pattern is seen as bright-fluorescent (Fig. 24), while the grey coloured oval dots are often presumed to be part of the base colour, which is not the case. Spiral rows are often not visible in shells of no exceptional preservation ⁽¹⁾.

Remarks

The Cretan specimens are very similar to Conus taurinensis Bellardi & Michelotti, 1841. To our knowledge, the type specimens of Conus taurinensis Bellardi & Michelotti, 1841, discussed by Sacco (1893b), Hall (1966) and Ferrero Mortara (1984), are stored in the Museo Regionale di Scienze Naturali, Turin, Italy (Annalaura Pistarino pers. comm.) (syntype MRSN BS.038.05.163), but no colour patterns are preserved. Hall (1966) stated that the type specimens of Conus taurinensis possess spiral cords on their last whorl. However, these specimens are very worn. Due to the bad preservation and the lack of colour patterns of the type material of C. taurinensis, we refrain from attributing with certainty the Cretan specimens to this species until more topotypes with colour patterns are observed ⁽¹⁾.

Erünal-Erentöz (1958) identified similar material from the Tortonian of the Adana Basin (Turkey) as Conus aff. clavatus Lamarck, 1810, a species originally described from the early Miocene (Aquitanian) of Dax, France. The type specimen of Conus clavatus Lamarck, 1810 (MHNG GEPI 46266, Lionel Cavin pers. comm.; Decrouez 1993) differs from the Turkish specimen, by the smooth and conical early spire whorls ⁽¹⁾.

Landau et al. (2013: pl. 82 figs 6–7) also figured one Turkish specimen as Varionoconus taurinensis (Bellardi & Michelotti, 1841), this time with a visible colour pattern which is identical to that of the Cretan specimens. We consider the specimens of both Erünal-Erentöz (1958) and Landau et al. (2013) as conspecific to Conus cf. taurinensis ⁽¹⁾.

Stratigraphic range

Serravallian of Turkey (Karaman Basin) (Landau et al. 2013); Tortonian of Turkey (Adana Basin) (Erünal-Erentöz 1958) and Greece (Messara Basin and Heraklion Basin, Crete) (this work) ⁽¹⁾.

Discussion ⁽²⁾– Varioconus taurinensis (Bellardi & Michelotti, 1840) is a strange little cone, in which the spire whorls of many specimens seem to have grown irregularly. This is also seen in specimens illustrated in the literature (see Sacco, 1893b; Hall, 1964). The height of the spire, spire angle and shape are very variable, ranging from low mammillate to relatively high and gradate. There are at least seven teleoconch whorls in the Turkish shells. The early whorls are flat-sided and on the third whorl a carina suddenly appears and the whorls become taller. Apart from the irregular spire, the dropped shoulder and weakly carinate last adult whorl are quite characteristic ⁽²⁾.

This species is unknown so far from the Paratethys ⁽²⁾.

Fig. 22. Morphotypes of Conus (Stephanoconus) cf. taurinensis Bellardi & Michelotti, 1841 ⁽¹⁾

from the Tortonian of Crete (Greece) in apertural and abapertural views and under UV light. Arrows show the similarities of the morphotypes figured herein.

A. Specimen MNHN.F.A83061.

B. Specimen MNHN.F.A83024.

C. Specimen MNHN.F.A83044.

D. Specimen AMPG(IV) 3814.

E. Specimen AMPG(IV) 3819.

F. Specimen MNHN.F.A83052.

G. Specimen AMPG(IV) 3818.

H. Specimen AMPG(IV) 3815.

I. Specimen MNHN.F.A83060.

J. Specimen AMPG(IV) 3823.

Scale bar = 1 cm.

Varioconus taurinensis (Bellardi & Michelotti, 1840) ⁽²⁾

Plate 83 fig. 6 RGM 777 896 (ex JvdV collection)

locality 17, Seyithasan, height 25,1 mm

Varioconus taurinensis (Bellardi & Michelotti, 1840)⁽²⁾

RGM 777 897 (ex JvdV collection)

locality 17, Seyithasan, height 27,3 mm.

Fig. 23. Conus (Stephanoconus) cf. taurinensis Bellardi & Michelotti, 1841 ⁽¹⁾

from the Tortonian of Crete (Greece), showing excellent preservation under natural light.

AMPG(IV) 3822

the continuous spiral pattern of dots and dashes, as well as the blotches on the spire whorls, are clearly visible.

Scale bar = 2 mm.

4. Varioconus taurinensis (Bellardi & Michelotti, 1840), NHMW 1847/0058/0510, locality 17, Seyithasan, height 29,5 mm ⁽²⁾

5. Varioconus taurinensis (Bellardi & Michelotti, 1840), NHMW 1847/0058/0511, locality 17, Seyithasan, height 28,2 mm ⁽²⁾

6. Varioconus taurinensis (Bellardi & Michelotti, 1840), NHMW 1847/0058/0984, locality 17, Seyithasan, height 31,1 mm ⁽²⁾

Conus (Stephanoconus) taurinensis (Bellardi & Michelotti, 1841)

stored at the Museo Regionale di Scienze Naturali, Turin

syntype MRSN BS.038.05.163

Colli Torinesi (Italy), Burdigalian

Scale bar = 1 cm.

Conus (Stephanoconus) taurinensis (Bellardi & Michelotti, 1841)

mm. 23,5 x 12,0

Rethymno a 800 m. s.l.m. – Creta

[AZFC N. 542-01]

Bibliografia Consultata