Lithoconus planospira ( Erünal-Erentöz, 1958 )

Kovács, Z. & Vicián, Z., 2013, Badenian (Middle Miocene) Conoidean (Neogastropoda) fauna from Letkés (N Hungary), Fragmenta Palaeontologica Hungarica 30, pp. 53-100 : 75

Lithoconus planospira ( Erünal-Erentöz, 1958)

(Fig. 41)

1856 Conus Mercati Brocchi – HÖRNES, pl. 2, fig. 2 only.

1897 Conus Mercati Brocchi – BRIVES, p. 19, pl. 5, fig. 9.

1958 Conus (Lithoconus) planospira n. sp. – ERÜNAL-ERENTÖZ, p. 111, pl. 17, fig. 4, pl. 18, fig. 1.

1960 Conus (Lithoconus) mercati var. daciae (Hoernes et Auinger) – KOJUMDGIEVA, p. 211, pl. 50, fig. 1.

1966 Conus (Lithoconus) mercati miocaenicus Sacco – SYMEONIDIS, p. 292, pl. 15, fig. 4.

1968 Conus (Lithoconus) planospira Erünal-Erentöz – HINCULOV, p. 152, pl. 38, fig. 10.

1972 Conus betulinoides Lamarck – DAVOLI, pl. 2, fig. 8.

Material – 20 specimens.

Description – Shell medium-sized to large (SL: 20–150). Spire flattened, apex pointed. Spiral whorls slightly concave, striate. Shoulder rounded. Body whorl broadly conical, outline convex, smooth with fine ridges at the base. Subsutural flexure asymmetrically curved.

Remarks – The Letkés specimens agree well with the types.The specimen figured by HÖRNES (1856, pl. 2, fig. 2) differs from M. mercati in morphology, it was interpreted as L. planospira by ERÜNAL-ERENTÖZ (1958). Without being cognizant of the latter arrangement, Hörnes’s specimen was regarded as D. berghausi by HALL (1964), although the characteristic morphology of D. berghausi differs in higher, convex spire. Similarly, D. berghausi var. planocylindrica Sacco (1893, p. 10 , pl. 1, fig. 15) seems to be close to L. planospira . The taxon differs from similar forms ( Monteiroconus mercati , M. tietzei and K. betulinoides ) in flattened spire; and from the latter in shorter, conical shell. The greater part of the L. planospira material of Letkés consists of medium-sized specimens with SL 35–45 mm; however, large forms also occur. One of these, a fragmentary giant specimen deserves attention: its SL is approximately 150 and MD is 80 mm.

Distribution – Algeria, Austria, Bulgaria, Greece, Italy, Portugal, Romania, Turkey (MM). Hungary: Letkés (MM).