Acteonidae d’Orbigny, 1843

Kiel, Steffen, Hybertsen, Frida, Hyžný, Matúš & Klompmaker, Adiël A., 2020, Mollusks and a crustacean from early Oligocene methane-seep deposits in the Talara Basin, northern Peru, Acta Palaeontologica Polonica 65 (1), pp. 109-138 : 129

Family Acteonidae d’Orbigny, 1843 Genus Acteon Montfort, 1810

Type species: Bulla tornatilis Linnaeus, 1758 , by original designation; Recent , North Atlantic Ocean .

“ Acteon ” sp.

Fig. 17D .

Material.— One specimen ( NRM Mo187065, H = 3.3 mm) from Cerro La Salina block 7, upper Oligocene, Talara Basin, Peru .

Remarks.—The single available specimen is 3.3 mm high, has a distinct shoulder, and is sculptured by numerous fine, beaded spiral cords. A similar species is Acteon annectens Meyer, 1885 , from the late Eocene Moodys Branch Formation in Mississippi, USA ( Dockery 1977). Acteonids have also been reported from Late Cretaceous seep deposits in Japan ( Kaim et al. 2009) and Oligocene seep deposits in Washington, USA (Kiel 2006). The generic name is given in inverted commas here because genera among the Acteonidae are mainly distinguished based on anatomy and radula rather than on conchological characters ( Rudman 1971).

Figures

Fig. 17. Neogastropod and opisthobranch gastropods from early Oligocene seep deposits at Cerro La Salina (block 2, A; block 4, B; block 6, E; block 7, D) and Belén seep site (C), Talara Basin, northern Peru. A, B. The buccinid Colus sekiuensis Kiel and Goedert, 2007. A. Large specimen (NRM Mo187062), showing shape of last whorl. B. NRM Mo187063, fragment of an early whorl. C. Buccinidae indet. (NRM Mo187064), fragmentary specimen. D. NRM Mo187065, the opisthobranch “Acteon” sp. in apertural (D1) and lateral (D2) views. E. The opisthobranch Cylichna sp. (NRM Mo187066).