Limicolaria omanensis, Neubert & Damme, 2012

Neubert, Eike & Damme, Dirk van, 2012, Palaeogene continental molluscs of Oman, Contributions to Natural History 20, pp. 1-28 : 14-15

Limicolaria omanensis sp. nov.

( Figs. 13–14 )

Type specimens: Holotype NMBE 5018977 ; paratypes NMBE 5018978–5018979 , MNHN/5 ; paratypes Wadi Darbat NMBE 5018980 – 5018981 , 5019048 – 5019049 .

Type locality: Thaytiniti , Dhofar, Oman .

Stratum typicum: Paludal biomicritic limestones of the Zalumah Formation.

Age: Late Priabonian.

Material: This species is also known from the fossil beds of Wadi Darbat.

Etymology: omanensis to describe the provenance of this new species.

Diagnosis: A medium sized fossil species of Limicolaria SCHUMACHER, 1817 , with a peculiar teleoconch pattern of axial riblets and a sutural cord.

Description: Shell turreted, fusiform; small protoconch (only preserved as stone core); teleoconch of ca. 7 whorls; whorls slightly rounded, with a sculpture of fine axial riblets running over the complete whorl; suture moderately deep, with a subsutural cord; below the cord, a small zone of spirals crossing the riblets and thus producing a characteristic reticulate pattern; aperture oval, upper right part acute.

Measurements: Holotype ( Fig. 13 ): H = 46.6 mm; W = 21.75 mm; h = 19.7 mm; w = 12.5 mm; Wh = 8; parataype ( Fig. 14 ): H = 40.56 mm.

Remarks: The species is mentioned by Roger & al. (1994) as Bulimus . The supraspecific affiliation of this species may be debatable. The endemic subulinid genus Riebeckia MARTENS, 1883 from Soqotra comprises several very large species, which are conchologically quite close to the afrotropical achatinoid Limicolaria species. They differ from those by their truncate columella, which is rounded and usually continuous in Limicolaria . Moreover, the species of Riebeckia are either smooth, or have a faint pattern of a reticulate sculpture on the teleoconch. None of those species has a subsutural cord nor clear axial riblets. Unfortunately, there is no fully grown specimen of Limicolaria omanensis sp. nov. with a preserved lower aperture, so it is not possible at the moment to judge about this character state. At the time being, this species is confined to the Achatinidae because of the resemblance in their teleoconch sculpture with some extant Limicolaria species from Eastern Africa.

Figures

Figs. 13–14: Limicolaria omanensis sp. nov. Fig. 13: Wadi Darbat, holotype NMBE 5018977 in frontal view. Fig. 14: Paratype NMBE 5018980, same locality, detail not to scale.