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

SANTELLI, MARÍA B.; DEL RÍO, CLAUDIA J.

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Lugar: Lawrence; Año: 2018 vol. 93 p. 1 - 25

0022-3360

Abstract.?Zygochlamys Ihering, 1907 is revised and three new genera of tribe Chlamydini are named: the monospecificearly Miocene genera Pixiechlamys new genus (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., containingPecten actinodes Sowerby, 1846 (type species) and Chlamys aurorae Feruglio, 1954. Zygochlamys is restricted toinclude Z. geminata (Sowerby, 1846) (type species), Z. jorgensis Ihering, 1907, and Z. sebastiani Morra, 1985. The presentanalysis increases the biostratigraphic usefulness of the group and improves taxonomic knowledge of the Neogenemolluscan 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. jorgensisis restricted to the early to middle Miocene of the Golfo San Jorge and northern Austral Basins, and Moirechlamysn. gen., 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 circumpolargenera such as Austrochlamys Jonkers, 2003 or Psychrochlamys Jonkers, 2003, rejecting its dispersal in theAntarctic Circumpolar Current, as has been proposed previously.