LA FLORA LIÁSICA DEL GRUPO PAMPA DE AGNIA, CHUBUT, PATAGONIA

Abstract

Fossil plants from the Pampa de Agnía Croup, from northern Chubut province, Patagonia, are described. Coniopteris meschiana, Otozamites chubutensis and O. sueroi are proposed as new species: worid-wíde distributed species as Sagenopteris rhoijoha, Otozamites hisloni and Ginkgoites ef. digitata (this last being the first cíted Ginkgoal from Argentine Liassic strata ) are also found, together with Scleropteris vincei and Otozamites ulbosaxatiiis, prevíously known from other Argentine Liassic sediments. The Pampa de Agnia Croup is composed of three formations: F. C<'>Puntudo Alto, F. Cabeza del Cristiano with its lateral equivalent F. Osta-Arena, and on top, F. C1 Carnerero. Thc Group is unconforrnably overlain by F. Puellman, which yieIded a Míddle Jurassic (Mntildeuse ) flora at the type locality. The present flora, together with species previously described from the same locatity (Herbst, 1964) confirms an Upper Míddle to Upper Liassic age at least for the two 10- wer formations. On the grouncls of, partly zeological and partly paleobotanical eviclence whích has not yet been thouroughly worked out, it is belíeved that contrary to other author's opinions, Formación Carnerero is still to beincluclecl in the Liassic sedimentary cycle.