Revista de la Asociación Geológica Argentina
versión On-line ISSN 1851-8249
HLEBSZEVITSCH, Julio C. y CORTINAS, Jorge S.. The oldest record of Echinoidea in Argentinaand the Permian-Early Jurassic contact in the Río Genoa region, Chubut. Rev. Asoc. Geol. Argent. [online]. 2009, vol.65, n.3, pp. 479-486. ISSN 1851-8249.
Echinoids of the genus Archaeocidaris M'Coy of LowerPermian age from Rio Genoa Formation, and Apiocrinitidae crinoids from thePliensbachian-Toarcian of upper member of the Mulanguiñeu Formation of LomasOccidentales, are described for the first time in Argentina; both localitiesare in the Chubut province. The observations made in these two localities ofthe Tepuel-Genoa Basin let us refer to Pre-Pliensbachian the continental sedimentationthat precedes de the marine beds with the crinoids described in this work, andabundant remains of bivalves, gastropods, braquiopods and ammonites. Thiscontinental low stand unit (Lower Member of the Mulanguiñeu Formation), fromEarly Jurassic, up to now was only known at the southern part of the TepuelGenoa Basin.
Palabras clave : Echinoidea; Permian; Lower Jurassic; Tepuel - Genoa Basin.