Conus (Lautoconus) sp. 4, 1923

Psarras, Christos, Merle, Didier & Koskeridou, Efterpi, 2022, Late Miocene Conidae (Mollusca: Gastropoda) of Crete (Greece). Part 2, European Journal of Taxonomy 816, pp. 1-70 : 29-30

Conus (Lautoconus) sp. 4

Figs 17 , 20 , 40I ; Table 9

Conus (Chelyconus)?pyrula – Caze 2010: 63, fig. 37a1–a3 (non Conus pyrula Brocchi, 1814 ).

Material examined

GREECE – Crete • 1 spec.; Apomarma; Messara Basin; Tortonian; 1990; Action spécifique du Muséum project (1989–1990) exped.; MNHN.F.A83015 .

TURKEY – Antakya • 1 spec.; Samandag; Antakya Basin; Piacenzian ; MNHN.F.A31529 .

Shell description

Medium-sized shell (SL max.: 29.43 mm). Early spire whorls conical to convex, of low to medium height. Later spire whorls conical in outline, with convex, smooth sutural ramp. Subsutural flexure moderately deep, strongly curved, moderately asymmetrical ( Fig. 40I ). Shoulder smooth at early spire whorls, slightly angulated at later spire whorls. Maximum diameter below shoulder. Last whorl conical, slightly widened. Aperture narrow, straight, widening towards slightly twisted fasciole. Shell smooth, except for two faded spiral cords near fasciole.

Colour pattern variation

The colour pattern on the spire whorls consists of irregular blotches. The colour pattern on the last whorl consists of two levels of colouration. The first one consists of fluorescent blotches. The second level consists of spirally arranged irregular rows of fluorescent dashes, interrupted by non-fluorescent tents. The tents can be either as small as dots, or small non-fluorescent dashes, or can be axially wide enough to unite with other tents and create an axial non-fluorescent area. The resulting pattern is variable and depends on the number of tents, as well as on the size of those tents. The Cretan specimen shows an axial unification of the tents, while the Turkish specimen displays a spiral unification of the tents, in the middle part of the last whorl.

We noticed that the specimen from Apomarma ( MNHN.F.A83015) had different grades of erosion, with non-fluorescent areas being more resistant to erosion, than those being previously with colour patterns (see Fig. 17A 4 in comparison to the right side of Fig. 17A 3 , where the shell is not so eroded). This might indicate that the substance enclosed in the shell structure, which is responsible for the pigments, is more prone to erosion than the non-pigmented areas.

Remarks

This species is placed in Lautoconus , as it has smooth early spire whorls and a convex sutural ramp. The Pliocene Turkish specimen identified by Caze (2010) as Conus (Chelyconus) ? pyrula Brocchi, 1814 and the Cretan specimen of Conus (Lautoconus) sp. 4 share smooth and convex spire whorls with a slightly angulated shoulder ( Fig. 17 ) and have a similar colour pattern. Thus, they very likely belong to the same species. The typical Pliocene Conus pyrula bears a colour pattern of axially arranged stripes. Conus (Lautoconus) sp. 4 differs from the Paratethyan species of Conus (Lautoconus) ( Harzhauser & Landau 2016) in the presence of tents in its colour pattern. Conus (Lautoconus) sp. 5 (see below) has a similar colour pattern of tents, but it differs morphologically from this species in the smooth outline of the spire whorls and the olive-like morphological outline. As such, we consider these specimens as two separate species. Unfortunately, in lacking more specimens with similar morphological characteristics and colour pattern, we do not name this species. Conus (Lautoconus) sp. 4 has a very common shell outline and is not easily distinguishable from other species without the help of UV light. The colour pattern is also reminiscent of extant species of Conus (Lautoconus) , such as the West African species Conus (Lautoconus) saragasae Rolán, 1986 ( Tenorio et al. 2020).

The morphological outline of Conus (Lautoconus) sp. 4 can be compared with several Conus (Stephanoconus) species discussed in this work (e.g., Conus (Stephanoconus) cf. taurinensis Bellardi & Michelotti, 1841 and Conus Conus (Stephanoconus) moissettei sp. nov.). Both species, however, possess the tuberculate early spire whorls, lacking in Conus (Lautoconus) sp. 4. Furthermore, their colour pattern is not comprised of tents.

Stratigraphic range

Tortonian of Greece (Messara Basin, Crete) (this work) and Piacenzian (Pliocene) of Turkey (Antakya Basin, Samandag Fm.) (see Tarı et al. 2013 for the age).

Figures

Fig. 17. Conus (Lautoconus) sp. 4 from the Tortonian of Crete (Greece) and the Piacenzian of Antakya (Turkey) (figure altered after Caze 2010), displayed under natural (A3–A5) and UV light. A. Specimen MNHN.F.A83015, Apomarma, displaying different grades of erosion (A3 box zoomed to A4). B. Specimen MNHN.F.A31529, Samandag (photo by Caze 2010). Scale bars: A1–A3, A5–B3 = 1 cm; A4 = 500 μm.

Fig. 20. PCA graph with nine species of Conus (Lautoconus) found in late Miocene localities of Crete (Greece). Conus (Lautoconus) sp. 1 is broken and cannot be included in the graph. Yellow dots = Conus (Lautoconus) eschewegi (Pereira da Costa, 1866); grey dots = Conus (Lautoconus) ictini sp. nov.; red dots = Conus (Lautoconus) sp. 2; blue dot = Conus (Lautoconus) sp. 3; black dot = Conus (Lautoconus) lauriatragei sp. nov.; brown dots = Conus (Lautoconus) damianakisi sp. nov.; purple dot = Conus (Lautoconus) cf. baldichieri Borson, 1820; green dots = Conus (Lautoconus) sp. 4; light blue dot = Conus (Lautoconus) sp. 5. Abbreviations: LW = length width ratio; PMD = position of maximum diameter; RD = relative diameter; RSH = relative height of spire.

Fig. 40. Examples of subsutural flexures. A. Conus (Lautoconus) eschewegi Pereira da Costa, 1866 (MNHN.F.A82976). B. Conus (Lautoconus) ictini sp. nov. (AMPG(IV) 3719). C. Conus (Lautoconus) sp. 1 (MNHN.F.A82982). D. Conus (Lautoconus) sp. 2 (AMPG(IV) 3756). E. Conus (Lautoconus) sp. 3 (MNHN.F.A83012). F. Conus (Lautoconus) cf. baldichieri Borson, 1820 (MNHN.F.A83013). G. Conus (Lautoconus) lauriatragei sp. nov. (MNHN.F.A83014). H. Conus (Lautoconus) damianakisi sp. nov. (AMPG(IV) 3802). I. Conus (Lautoconus) sp. 4 (MNHN.F.A83015). J. Conus (Lautoconus) sp. 5 (AMPG(IV) 3861). K. Conus (Stephanoconus) cf. taurinensis Bellardi & Michelotti, 1841 (AMPG(IV) 3808). L. Conus (Stephanoconus) moissettei sp. nov. (MNHN.F.A83071). M. Conus davolii sp. nov. (MNHN.F.A83091). N. Conus fuscocingulatus Hörnes, 1851 (AMPG(IV) 3858). O. Conus (Plagioconus) elatus Michelotti, 1847 (AMPG(IV) 3862). P. Conus (Plagioconus) sp. (AMPG(IV) 3890). Q. Conus (Plagioconus) sp. (AMPG(IV) 3898). R. Conus (Plagioconus) aquensis d’Orbigny, 1852 (AMPG(IV) 3907). Not to scale.

Fig. 4. Conus (Lautoconus) ictini sp. nov. from the Tortonian of Crete (Greece) on apertural, abapertural and apical views, under natural (A1, A3, A4, B1) and UV light. A. Holotype AMPG(IV) 3719, Tefeli. B. Paratype AMPG(IV) 3720, Tefeli. C. Paratype AMPG(IV) 3718, Tefeli. D. Specimen AMPG(IV) 3716, Achladhia. Scale bar = 1 cm.

Fig. 3. Elements constituting the colour pattern of Conus (Lautoconus) eschewegi Pereira da Costa, 1866 (MNHN.F.A82974) from the Tortonian of Crete (Greece). Scale bar = 1 cm.