Nerinea, Deshayes, 1827

Ferrari, S. Mariel, 2013, New Early Jurassic gastropods from west-central Patagonia, Argentina, Acta Palaeontologica Polonica 58 (3), pp. 579-593 : 590-591

Nerinea ? sp. 2

Fig. 4G–I .

Material.—MPEF−PI 4124 to 4126; fragmentary and replaced teleoconchs. LO 29 site from Lomas Occidentales locality, Chubut province, Argentina, Mulanguiñeu Formation, Lower Jurassic, Upper Pliensbachian, Lower Toarcian.

Dimensions.—MPEF−PI 4124: height 10.8 mm; width 6 mm. MPEF−PI 4125: height 10.2 mm; width 7 mm.

Description.—Dextral, anomphalous, turriculate and small sized shell. The protoconch is not preserved. The fragmentary teleoconch consists of three/four flat to slightly concave whorls. Sutures are weakly incised. The shell is smooth or lacks a well developed ornament; a weak peripheral spiral keel borders the sutures on each teleoconch whorl. The base is flat, angular, and is bordered by a strong spiral keel. The aperture is quadrangular.

Remarks.—The present material shows some typical characters of Nerinea ; however, due to the lacks of well preserved specimens, it is left in open nomenclature until a new material is available.

Nerinea ? sp. 2 differs from Nerinea ? sp. 1 in having more flattened whorls; however, none of these species show crucial characters for a correct taxonomic assignment, such as columellar folds and apertural elements.

Figures

Fig. 4. Early Jurassic gastropods from Lomas Occidentales and Cerro La Trampa fossiliferous localities.A–C. Globularia cf. catanlilensis (Weaver, 1931). A. MPEF−PI 4112; teleoconch in lateral (A1, A2) and apertural (A3) views. B. MPEF−PI 4114; teleoconch in lateral (B1, B2) and latero−apical (B3) views. C. MPEF−PI 4116, teleoconch in lateral views (C1, C2). D. Globularia sp. MPEF−PI 4119; teleoconch in lateral (D1) and apertural (D2) views. E. Naricopsina? sp.; MPEF−PI 3560, teleoconch in latero−apical views (E1, E2). F. Nerinea? sp. 1. MPEF−PI 4123, fragmentary teleoconch in lateral views (F1, F2). G–I. Nerinea? sp. 2. G. MPEF−PI 4124, fragmentary teleoconch in lateral view. H. MPEF−PI 4125, fragmentary teleoconch in lateral view. I. MPEF−PI 4126, fragment of last teleoconch whorl in lateral view. Scale bars: A–D 10 mm, E–I 3 mm.