Lower and Midle Cambrian rhynchonelliform brachiopods from the Precordillera terrane of Argentina

BENEDETTO, J.L. Y FOGLIA, R.

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Lugar: Lawrence; Año: 2012 vol. 86 p. 273 - 281

0022-3360

The first Cambrian rhynchonelliformean brachiopods are described from the Precordillera mountain belt of west-central Argentina, including the new species Wimanella mollesensis and Nisusia ancauchensis. Other forms are Diraphora  cf. D. borealis (Walcott), Diraphora sp., and an indeterminate bohemiellid. Brachiopods come from the lowermost part of the Precordilleran Cambrian succession (El Estero and Soldano Members of the La Laja Formation, Cerro Totora Formation) and from the Ancaucha olistolith within the Los Sombreros olistostrome. The associated trilobites constrain the fossiliferous levels to the Bonnia-Olenellus, Poliella denticulata and Ehmaniella Biozones. A re-assessment of paleobiogeographic affinities of Lower and early Middle Cambrian rhynchonelliform brachiopods using cluster analysis supports the existence of a widespread warm-water Tropical Realm to which the described Precordilleran faunas belong and a more restricted Mediterranean Realm developed on the temperate, mixed clastic-carbonate platforms.