Trace fossils from the Desejosa Formation (Schist and Greywacke Complex, Douro Group, NE Portugal): new Cambrian age constraints

Abstract

Trace fossils from a new locality in the Desejosa Formation, Freixo de Espada à Cinta area, northeast Portugal, are described, including Teichichnus rectus and the first Cambrian record from Iberia of the ichnogenus Rosselia, identified as R. cf. socialis. A literary review of the Cambrian record of Rosselia reveals no occurrences older than Cambrian Age 3. The occurrence of Rosselia in the Desejosa Formation therefore adds evidence to that of earlier reports on trilobite remains from the upper part of the Desejosa Formation for a Cambrian age of this unit. Both Rosselia and Teichichnus are zindicative of the Cruziana ichnofacies, which is representative of a shallow-marine depositional environment, consistent with earlier interpretations for the depositional conditions of the upper part of the Desejosa Formation in this sector, and in the equivalent Cambrian units in Spain.