Leptoconus hirmetzli, Kovács & Vicián, 2013

Leptoconus hirmetzli View in CoL sp. n.

( Figs 30–37)

Holotype – Hungarian Natural History Museum , Department of Palaeontology and Geology; inventory number: PAL 2013.3.1. ( Figs 34–36).

Paratypes – 1st paratype: Hungarian Natural History Museum , Department of Palaeontology and Geology; inventory number: PAL 2013.4.1 ; 2nd, 3rd and 4th paratypes: private collection of Tamás Hirmetzl ( Hungary); 5th, 6th, 7th, 8th, and 9th paratypes: Hungarian Natural History Museum , Department of Palaeontology and Geology; inventory numbers: PAL 2013.5.1 .–PAL 2013.9.1.

Type strata – Lower Badenian (Middle Miocene) clayey sand.

Type locality – Letkés, Börzsöny Mts, Hungary.

Derivation of name – In honour of Dr Tamás Hirmetzl, Hungarian fossil collector.

Diagnosis – Large shell with high and turriculate spire, paucispiral protoconch, conical and elongate body whorl, narrow aperture, and asymmetrically curved subsutural flexure.

Description – The shell is large, elongate, and biconical. The spire is high, pointed, and turriculate, with 33–35º spire angle. The outline is straight on the juvenile specimens, while slightly concave on the adults. The protoconch consists of 2 whorls. The adult teleoconch consists of 12 high spiral whorls. The early 6 teleoconch whorls are angulate and weakly tuberculate in the middle; the late whorls are rounded and smooth. The shoulder of the body whorl is subangulate to rounded. The body whorl is smooth, elongate, conical, the outline is straight. Colour pattern cannot be traced. The aperture is narrow and straight. The subsutural flexure is asymmetrically curved and deep.

Remarks – The Letkés specimens described here differ from the Conoidean taxa recorded in the literature, therefore they are regarded as representatives of a new species. This species belongs to Leptoconus on the basis of the morphological resemblance between our specimens and two representatives of the genus: the extinct L. aratispira (Pilsbry, 1905) , and the extant L. milneedwardsi milneedwardsi (Jousseaume, 1894) . Fossil records of Leptoconus are known from the Pliocene of Japan, Java, and Gulf of Aqaba.

Comparisons – Plagioconus oblongoturbinatus ( Sacco, 1893) from the Italian Miocene is a similar form in size and morphology; it clearly differs, however, in much lower spire characterised by only 5–8 wholly angulate or flat spiral whorls. Leptoconus melitosiculus (Gregorio, 1895) from the Miocene of Malta resembles in overall morphology, but differs in lower and step-like spire. Turriconus excelsus (Sowerby, 1908) differs in much broader shell with angulate spiral whorls and shoulder. Leptoconus aratispira differs in lower and striate spire and in ornament- ed shell. The rare L. milneedwardsi milneedwardsi from the Indo-Pacific region seems to be the most closely allied form. It has a large shell (80–174 mm) characterised by a remarkably high spire, tuberculate early whorls and rounded to angulate shoulder, but it also differs in wholly angulate spiral whorls.

Phylogenetic connections – Leptoconus hirmetzli sp. n. is of uncertain origin; it probably derived from genus Conilithes . The overall morphology of two moderately small species, C. canaliculatus and C. antidiluvianus is quite similar. The former seems to be the closest form with its biconical shape; however, some large C. antidiluvianus specimens illustrated by SACCO (1893, pl. 4, figs 32–34) are also similar in morphology, except the ornamentation. On the other hand, L. hirmetzli sp. n. has an obvious relation with the recent L. milneedwardsi milneedwardsi . Based on the striking resemblance between the two taxa, the new species might be regarded as both the ancestor of the latter, and the earliest representative of the genus. Although the seaway between the Mediterranean-Paratethyan and the Indo-Pacific regions ceased from the Serravallian, it had been open during the Langhian. The connection of the new fossil species and the extant taxa needs to be verified by future Neogene conoid records from East Africa or the adjacent regions.