Distinctive Silurian chitinozoans from the Itacurubí Group (Vargas Peña Shale), Chaco Basin, Paraguay

Abstract

Three chitinozoan species are described from the rich assemblage present in the Lower Silurian Vargas Peña Shale, Paraguay. Plectochitina paraguayensis and Eisenackitina bejui are newly established. A new species of Pterochitina is described in open nomenclature. The Vargas Peña chitinozoans differ from those previously described from the Lower Silurian of South America and are the first to be illustrated from the Paraguayan Silurian. Acritarchs from the Vargas Peña Shale are interpreted to represent a middle Llandovery age, closely comparable to that determined using graptolites.