The homalonotid trilobite Burmeisteria Salter, 1865 in the Lower Devonian of Argentina: new data in the context of Southwestern Gondwana

The homalonotid trilobite Burmeisteria Salter, 1865 is revised based on fossils from the Lower Devonian (Pragian) of central western Argentina (the Talacasto Formation in the Precordillera Basin).  In contrast with other closely related Devonian marine basins from South America (mainly Bolivia, Brazil and Uruguay), the only species recognized in Argentina include Burmeisteria herschelii (Murchison, 1839) and B. notica (Clarke, 1913). Some description of the internal structure of the carapace is provided. Sometimes described as true granulation, the filling of the poral channels exposed by decortication, is a taphonomic feature which warrants to synonymize species otherwise based on this character. The possible function as locking device during enrollment, allowing long-term defensive behaviour with a minimum of muscular energy, is proposed for the antero-ventral process of the rostral plate. Burmeisteria is considered an Upper Silurian to Middle Devonian representative of Southern Gondw...