The trilobite Maurotarion megacephalum sp. nov. (Aulacopleuridae) in the Lower Devonian of Argentina: phylogenetic and paleobiogeographic remarks

Maurotarion megacephalum sp. nov., from the Pragian (Lower Devonian) of the Talacasto Formation, Precordillera basin, central-west Argentina, is described and interpreted as the first Malvinokaffric species of the genus outside the endemic subgenus M. (Malvinotarion). Based mainly on librigenal characters, the coevalM. periergum, from the Wenban Limestone, Nevada, U. S. A., is considered the closest allied taxon. Both species are interpreted as those most closely related to M. (Malvinotarion). Evidence suggests faunal exchange between low and high paleolatitudes for the Pragian, a hypothesis previously discarded in light of low sea level conditions interpreted during this time, and linked to a pattern of vicariance and radiation previously recognized from Malvinokaffric Maurotarion species.