Conus (Plagioconus) sp., 2009

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 : 48-52

Conus (Plagioconus) sp.

Figs 30–31 , 36 , 40P–Q ; Table 14

Conus (Chelyconus) puschi – Symeonidis & Konstantinidis 1968: pl. 7 fig. 3 (non fig. 17 = Conus (Plagioconus) aquensis d’Orbigny, 1852 ) (non Conus elatus Michelotti, 1847 ).

Material examined

GREECE – Crete • 4 specs; Achladhia ; 1964; Nikolaos Symeonidis leg.; AMPG ( IV) 3881 to AMPG ( IV) 3884 • 1 spec.; same collection data as for preceding AMPG ( IV) 3887 • 4 specs; Filippi; 35.035° N, 25.250° E; 2017; Christos Psarras leg.; AMPG(IV) 3890 to AMPG(IV) 3893 • 1 spec.; same locality as for preceding; Efterpi Koskeridou leg.; AMPG(IV) 3894 • 1 spec.; same locality as for preceding; AMPG ( IV) 3895 • 2 specs; Panassos; 35.130° N, 24.986° E; 2017; Christos Psarras leg.; AMPG(IV) 3896 to AMPG(IV) 3897 • 2 specs; Psalidha; 35.085° N, 24.962° E; Christos Psarras leg.; 2018; AMPG(IV) 3898 to AMPG(IV) 3899 • 5 specs; same collection data as for preceding; AMPG ( IV) 3901 to AMPG ( IV) 3905 • 1 spec.; Tefeli; Efterpi Koskeridou leg.; AMPG(IV) 3906 • 1 spec.; 1990; Action spécifique du Muséum project (1989–1990) exped.; MNHN.F.A83092 • 2 specs; Panassos; 35.130° N, 24.986° E; Didier Merle leg.; MNHN.F.A83094 to MNHN.F.A83095 • 1 spec.; 1990; Action spécifique du Muséum project (1989–1990) exped.; MNHN.F. A83096 • 1 spec.; Partira; 1990; Action spécifique du Muséum project (1989–1990) exped.; MNHN.F.A83097 • 1 spec.; Psalidha; 35.085° N, 24.962° E; Didier Merle leg.; MNHN.F.A83098 .

Shell description

Medium-large-sized shells (SL max.: 76.1 mm). Spire whorls medium to high, with conical outline. Protoconch multispiral. Early spire whorls conical, slightly elevated and beaded, with angulated shoulder. Late spire whorls conical, flat to striated, with straight to convex sutural ramp. Suture incised, of variable depth. Subsutural flexure moderately deep ( Fig. 40P ) to deep ( Fig. 40Q ), moderately curved, strongly asymmetrical. Sutural ramp straight to slightly inflated and convex. Shoulder smooth to subangulated. Spiral angulation at shoulder, as separation of last whorl and sutural ramp. Aperture straight, narrow. Last whorl elongated, conical. Fasciole smooth, elongated, slightly twisted. Faint spiral cords at anterior part of last whorl.

Description of colour pattern

The first pattern level consists of an alteration of fluorescent spiral bands, on a non-fluorescent base colour, with one thin fluorescent band at the position of the maximum diameter, another wide fluorescent band near the shoulder of the shell, and, in some shells, a third smaller band present on half of the anterior part of the last whorl ( Fig. 30B ). The second level consists of rows of dots and dashes, which are axially or spirally arranged on the surface of the shell, on top of the first field. The colour pattern of the spire whorls consists of fluorescent flammulae of irregular width, usually continuing on the last whorl, as axial dots or dashes ( Fig. 30G ). The pattern is not consistent in all shells, as some shells under the UV light display either faded patterns ( Fig. 30C ), one pattern on the last whorl ( Fig. 30B ), or none at all ( Fig. 30D ).

Remarks

The Cretan specimens are mostly broken, but the remaining shell surfaces are in pristine condition, the beads on the spire whorls are visible and, most importantly, the colour patterns can be distinguished under UV light ( Fig. 31 ). The specimens of Conus (Plagioconus) sp. display variable shoulder angulation height of the spire ( Fig. 30 ; Table 14 ). The colour pattern is consistent, with fluorescent bands and occasional spiral or axial dots and dashes. Some of the studied specimens have previously been identified by Symeonidis & Kostantinidis (1968) as Conus puschi , here regarded as a synonym Conus (Plagioconus) elatus Michelotti, 1847. After studying the material, we noticed that the overall spire outline of Conus (Plagioconus) sp. is more straight-sided, than Conus (Plagioconus) elatus Michelotti, 1847 , which has a slightly inflated outline on the middle whorls. The spire of Conus (Plagioconus) elatus then continues to much more pronounced later spire whorls, which is not the case for Conus (Plagioconus) sp. Also, the shells of Conus (Plagioconus) elatus have almost no colour pattern (only flammulae and some blotches on the spire whorl), while the specimens of Conus (Plagioconus) sp. are much more flamboyant. Hall (1966) illustrated specimens of several varieties of other species and considered them as synonyms of Conus aquensis d’Orbigny, 1852 . These specimens are a type specimen of Conus oboesus ? var. paucispirata Sacco, 1893 , a type specimen of Conus oboesus ? var. elatoides Sacco, 1893 , a type of Conus puschi var. pseudobiconica Sacco, 1893 , a type specimen of Conus pushi var. peracutolonga Sacco, 1893 and a type specimen of Conus elatus var. fusuloparva Sacco, 1893 . These specimens have the same conical, elongated spire whorls and angulation at the shoulder as Conus (Plagioconus) sp.

As we had no access to their colour patterns, we cannot check the synonymy of Hall (1966).A comparison with the syntype (MNHN.F. A13061 ) of Conus (Plagioconus) aquensis ( Fig. 32 ) from the early Miocene of the Aquitaine Basin shows that Hall’s specimens possess more angulated shoulders, high conical spires and relatively narrower diameters (RD). Two specimens named as Conus puschi from Davoli (1972: pl. 8 figs 17a–b, 19) have an elongated spire similar to that of the studied specimens ( Fig. 30B 1– C 2 ), but the spire whorls are not distinctly elevated and there is a slight angulation at the shoulder. We also wait for their colour pattern descriptions in order to compare to the Cretan specimens.

Stratigraphic range

Tortonian of Greece (Messara Basin and Sitia Basin, Crete ( Symeonidis & Kostantinidis 1968; this work)).

Figures

Fig. 30. Conus (Plagioconus) sp. from the Tortonian of Crete (Greece) in apertural, abapertural and apical views, under natural (A1, B1, B3, C1, D1, E1, F, G1) and UV light. A. Specimen AMPG(IV) 3901, Psalidha. B. Specimen AMPG(IV) 3890, Filippi. C. Specimen MNHN.F.A83095, Panassos. D. Specimen AMPG(IV) 3881, Achladhia. E. Specimen AMPG(IV) 3903, Psalidha. F. Specimen AMPG(IV) 3904, Psalidha. G. Specimen AMPG(IV) 3902, Psalidha. Scale bar = 1 cm.

Fig. 31. Conus (Plagioconus) sp. from the Tortonian of Crete (Greece), displaying elements of colour pattern (A) and shape of the protoconch (B–C).A. SpecimenAMPG(IV) 3901, Psalidha.B–C. Specimen AMPG(IV) 3891, Filippi. Scale bars: A = 1 cm; B = 500 μm; C = 1 mm.

Fig. 36. PCA graph with three species of Conus (Plagioconus) found at late Miocene localities of Crete (Greece). Black dots = Conus (Plagioconus) elatus Michelotti, 1847; red dots = Conus (Plagioconus) aquensis d’Orbigny, 1852; yellow dots = Conus (Plagioconus) sp. 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. 32. Two syntypes of Conus (Plagioconus) aquensis d’Orbigny, 1852 from Saint-Paul-lès-Dax in the Aquitaine Basin, France, in apertural, abapertural and apical views, under natural (A1–A2, A5, A7, B1–B2, B5, B7) and UV light (MNHN.F.A13061). Scale bar = 1 cm.

Fig. 1. General map Crete, showing the localities where the material was collected: 1 = Tylissos; 2 = Keramoutsi; 3 = Panassos; 4 = Apomarma; 5 = Psalidha; 6 = Adhraktia; 7 = Tefeli; 8 = Partira; 9 = Filippi; 10 = Makrilia; 11 = Achladhia; 12 = Voleones.

Fig. 2. Conus (Lautoconus) eschewegi Pereira da Costa, 1866 from the Tortonian of Crete (Greece) on apertural and abapertural views, under UV light, displaying morphological and colour pattern variations. A. Specimen MNHN.F.A82973, Crete. B. Specimen MNHN.F.A82974, Crete. C. Specimen AMPG(IV) 3702, Filippi. D. Specimen MNHN.F.A82980, Crete. E. Specimen MNHN.F.A82981. F. Specimen MNHN.FA82978, Crete. G. Specimen AMPG(IV) 3711, Tefeli. H. Specimen AMPG(IV) 3706, Filippi. Scale bar = 1 cm.