Trilobites de la familia Olenidae en el Ordovícico Inferior (Arenigiano) de la Cordillera Oriental argentina

WAISFELD, B.G.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2001 vol. 38 p. 195 - 211

0002-7014

Olenid trilobites from the Acoite Formacion (Arenigian) that crops out in the Argentine Cordillera Oriental are described and figured.Eight species are reported, three of which are new: Porterfieldia cuadrata sp. nov., Hypermecaspis occidentalis sp. nov. and Hypermecaspis chamarrensis. Porterfieldia is reported from the Lower Ordovician of Argentina for the first time. Likewise, Saltaspis Harringotn and Leanza had not previously been recorded in strata of early Arenig age of the Cordillera Oriental. These records significantly increase the diversity of the group in the Arenigian of the Cordillera Oriental. Olenids occur in moderately to highly diversified trilobite-dominated assemblages, accounting for transitional associations between the raphiphorid and the olenid community type.