New Early Permian Bivalvia fauna from Rio Genoa Formation (Patagonia, Chubut Province, Argentina).

PAGANI, M.A. AND FERRARI, S.M.

ALCHERINGA

TAYLOR & FRANCIS LTD

Año: 2011 p. 355 - 376

0311-5518

Fourteen Bivalvia species are described from the Lower Permian Río Genoa Formation,exposed in the southern Tepuel-Genoa Basin (Chubut Province, Argentina), of which one,Fletcheripecten genoensis, is new. The studied specimens are well preserved, retaining finedetails of the ornament and shell morphology. Palaeotaxodonta is represented by twospecies of Nuculopsis and four species of Phestia; Pteriomorphia by five species in fivegenera; and Heteroconchia by three informal species. Most of the species recorded alsooccur in the northern part of Tepuel-Genoa Basin and allow demarcation of new anddistinct marine intervals in the Río Genoa Formation, which was classically interpreted torepresent continental deposits. The bivalve fauna confirms a Cisuralian (Early Permian)age for the Río Genoa Formation and offers potential for improved regional and globalcorrelations.