Promathildia subnodosa ( Münster, 1841 )

Hausmann, Imelda M., Nützel, Alexander, Roden, Vanessa Julie & Reich, Mike, 2021, Palaeoecology of tropical marine invertebrate assemblages from the Late Triassic of Misurina, Dolomites, Italy, Acta Palaeontologica Polonica 66 (1), pp. 143-192 : 167

Promathildia subnodosa ( Münster, 1841)

Fig. 21B .

1841 Fusus subnodosus n. sp.; Münster 1841: 124, pl. 13: 51.

1894 Promathildia subnodosa ; Kittl 1894: 243, pl. 9: 36–45.

1978 Promathildia subnodosa ; Zardini 1978: 50–51, pl. 35: 4–9.

?1995 Promathildia subnodosa ; Bandel 1995: 8, pl. 2: 5, 7, pl. 3: 1–4, 6, 7.

2015 Promathildia subnodosa ; Hausmann and Nützel 2015: fig. 8H.

Material.—One teleoconch fragment (PZO 12730) from Misurina Landslide surface sample, Italy, Carnian, Triassic.

Description.—A single teleoconch fragment consisting of about 5 whorls, 12 mm high, 4.7 mm wide; whorls convex with median angulation; growth lines distinct, sometimes thread-like, orthocline below suture and then curving forward so that they become markedly opisthocline in the two thirds of whorls; two prominent spiral cords, one at mid-whorl angulation, the other half way between mid-whorl and abapical suture; both main spiral cords undulating to nodular at intersections with opisthocline axial ribs, numbering 10–14 per whorl; a third faint spiral cord somewhat below suture; base convex, with two distinct spiral cords and additional spiral lirae.

Remarks.—This is a rather variable species; the specimen at hand is close to some of the specimens illustrated by Kittl (1894) and Zardini (1978) as P. subnodosa . The identity of the specimens illustrated by Bandel (1995) is doubtful because they represent early juvenile shell portions only.

Stratigraphic and geographic range.—Carnian, Upper Triassic; northern Italy (southern Alps, Cassian Formation; Apulia, Raibl Formation) ( Diener 1926; Kutassy 1940).

Figures

Fig. 21. Heterobranch gastropods from Misurina Landslide, northern Italy, Cassian Formation, Carnian, Upper Triassic. A. Promathildia cf. decorata Klipstein, 1843), PZO 12729, in lateral (A1) and apical (A3) views; A2, close up to show heterostrophic protoconch, in lateral view. B. Promathildia subnodosa (Münster, 1841), PZO 12730, in apertural view. C. Promathildia cf. milierensis Zardini, 1980; PZO 12722, in apertural view (C1); C2, close up to show heterostrophic protoconch, in lateral view; C3, close up to show heterostrophic protoconch, transition to teleoconch well visible, in lateral view. D. Promathildia cf. milierensis Zardini, 1980, PZO 12725, in lateral view. E. Promathildia cf. milierensis Zardini, 1980, PZO 12723, in lateral view. F. Promathildia cf. milierensis Zardini, 1980, PZO 12726, in lateral view. G. Camponaxis lateplicata (Klipstein, 1843), PZO 12731, in lateral view. H. Promathildia cf. milierensis Zardini, 1980, PZO 12727, in lateral view. I. Promathildia cf. milierensis Zardini, 1980; PZO 12724, in lateral view.