Globularia sp.

Ferrari, S. Mariel, 2013, New Early Jurassic gastropods from west-central Patagonia, Argentina, Acta Palaeontologica Polonica 58 (3), pp. 579-593 : 588

Globularia sp.

Fig. 4D .

Material.—MPEF−PI 4119; fragmentary and re−crystallized teleoconch. LT 1 site from Cerro La Trampa locality, Chubut province, Argentina, Mulanguiñeu Formation, Upper Pliensbachian–Lower Toarcian, Lower Jurassic.

Dimensions.—MPEF−PI 4119: height 49 mm; spire height

27.2 mm; width 42 mm; spire width 25.6 mm; last whorl height 29 mm.

Description.—Dextral, anomphalous, naticiform, globular, low spired, medium sized shell with gradate outline. The protoconch is not preserved. The teleoconch comprises four fragmentary whorls; the last one more expanded than the earlier whorls. Last teleoconch whorl is about half of the maximum height of the shell. The upper portion of the whorls forms a very narrow sutural ramp which gives the periphery of the shell a strongly angular shape, becoming wide and concave toward the lower portion. The suture is weakly incised. The shell is smooth or lacks a well developed ornament. The base is convex and the aperture fragmentary, with the inner lip concave. Umbilical characters are absent.

Remarks.—The present material shows the typical characters of Globularia , due to the imperfect conditions, however, I decided to leave this species in open nomenclature.

Globularia sp. is similar to Globularia cf. catanlilensis ( Weaver, 1931) ; however, Globularia sp. has a more gradate outline shell, and the last teleoconch whorl has a height approximately equal to its width.

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.