Camponaxis lateplicata (Klipstein, 1843)

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 : 167-168

Camponaxis lateplicata (Klipstein, 1843)

Fig. 21G .

Material.—One shell (PZO 12731) from Misurina Landslide bulk sample, Italy, Carnian, Triassic.

Description.—Shell high-spired; whorls convex with slight angulation high on the whorls; whorl ornamented with axial ribs and spiral cords of about same strength with intersection not or only slightly nodular; axial ribs, straight orthocline, rounded, separated by wide interspaces, numbering up to 20 per whorl; spiral cords of variable strength and irregularly species; two adapical spiral cords particularly weak.

Remarks.—This specimen resembles Bandel’s (1995) illustrations of Camponaxis lateplicata ( Bandel 1995: pl. 13: 9; pl. 14: 1–5) and is probably conspecific. However, it is questionable whether Bandel’s (1995) material is conspecific with Klipstein’s (1843) type specimen which AN has examined at the Museum of Natural History in London. This type specimen is relatively large, fusiform and has fewer but stronger axial ribs. It is therefore likely that Camponaxis has a misidentified type species.

Family Cornirostridae Ponder, 1990

Genus Bandellina Schröder, 1995

Type species: Bandellina laevissima Schröder, 1995 ; Poland, Early Cretaceous.

Remarks.—The genus was discussed by Bandel (1996) and Kaim (2004) who pointed out its resemblance to the modern sunken wood and hot vent species Hyalogyra Marshall, 1988 . Kaim (2004) did not follow Bandel’s (1996) assignment to the family Cornirostridae but left the family assignment open.

Bandellina compacta Nützel and Hausmann sp. nov. Fig. 22 .

ZooBank LSID: urn:lsid:zoobank.org:act:6B8D87DF-6B27-402E-B0A3-EB2908DB78DF

Etymology: In reference to the compact shell form.

Holotype: PZO 12840 , specimen with larval shell and 2 teleoconch whorls.

Type locality: Lago Antorno, near Cortina d’Ampezzo , northern Italy. Type horizon: Cassian Formation ; lower Carnian, Upper Triassic .

Material.— Two specimens ( PZO 12839 , 12840 ) from Lago Antorno bulk samples, Italy, Carnian, Triassic .

Description.—Shell low-spired, turbiniform; specimen comprises 3.6 whorls (two larval), 0.9 mm wide, 0.7 mm high; protoconch blunt, comprising about two whorls; initial whorl sinistral, sunken, smooth; second protoconch whorl dextral, round, convex with axial subsutural rib character of strengthened growth lines; protoconch clearly demarcated from teleoconch by a suture; teleoconch smooth, with evenly convex whorls embracing somewhat above periphery; base evenly convex; minutely phaneromphalous, covered with numerous fine spiral ribs.

Remarks.— Bandellina compacta differs from B. cassiana and B. laevissima in being more high-spired and in having a narrower umbilicus. Moreover, B. cassiana and B. laevissima lack spiral ribs on the base and axial riblets on the last larval whorl.

Stratigraphic and geographic range.—Only known from the Carnian, Upper Triassic; northern Italy (Cassian Formation).

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.

Fig. 22. Cornirostrid gastropod Bandellina compacta Nützel and Hausmann sp. nov. from Lago Antorno, northern Italy, Cassian Formation, Carnian, Upper Triassic. Holotype PZO 12840, in apical (A1) and apertural (A2) views; heterostrophic protoconch, in apical (A3), lateral (A4), and oblique lateral A5) views.