Neogene Pectinidae (Bivalvia) of Tribe Chlamydini Teppner, 1922 in Patagonia (Argentina): Zygochlamys Ihering, 1907 and three new genera

SANTELLI, MARÍA BELÉN; DEL RIO, CLAUDIA JULIA

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Lugar: Lawrence; Año: 2019 vol. 93 p. 312 - 336

0022-3360

Zygochlamys Ihering, 1907 is revised and three new genera of Tribe Chlamydiniare named: the monospecific early Miocene genera Pixiechlamys n. gen. (type species: Pecten quemadensis Ihering, 1897) and Chokekenia n. gen. (type species: Zygochlamys nicolasi Morra, 1985), and the late Miocene-early Pliocene Moirechlamys n. gen., containing Pecten actinodes Sowerby, 1846 (type species) and Chlamys aurorae Feruglio, 1954. Zygochlamys is restricted to include Z. geminata (Sowerby, 1846) (type species), Z. jorgensis Ihering, 1907 and Z. sebastiani Morra, 1985. The present analysis increases the biostratigraphic usefulness of the group and improves taxonomic knowledge of the Neogene Molluscan Assemblages defined previously for Patagonia. Zygochlamys geminata is confined to the latest Oligocene-early Miocene interval of the Austral Basin of Patagonia (Argentina) and to the early Miocene of Chile, Z. jorgensis is restricted to the early to middle Miocene of the Golfo San Jorge and northern Austral Basins, and Moirechlamys, the most widespread genus, occurs in the late Miocene-early Pliocene of the Austral, Golfo San Jorge, Valdés and Colorado basins. All these genera are endemic to southern South America; Zygochlamys is not related to other circumpolar genera such as Austrochlamys Jonkers, 2003 or Psychrochlamys Jonkers, 2003, rejecting its dispersal in the Antarctic Circumpolar Current as has been proposed previously.