Maderas fósiles afines a Araucariaceae de la Formación Bajo Barreal, Cretácico Tardío de Patagonia central (Argentina)

Abstract

Fossil woods with Araucariaceae affinity from the Bajo Barreal Formation, Late Cretaceous of central Patagonia (Argentina). Fossil woods collected from sediments of the Late Cretaceous Bajo Barreal Formation (Patagonia, Argentina) are described and assigned to the morphogenus Agathoxylon. The woods have weakly marked growth ring boundaries, uniseriate to rarely biseriate radial pitting, with contiguous circular to hexagonal bordered pits, alternate when biseriate. Rays are uniseriate and low, usually with up to 5 cells in height. Cross-field pits are not very well preserved; they seem to be elliptical and oblique and 3-5 per cross-field. The woods are anatomically similar to extant South American species of Araucaria and to several fossil species, particularly Agathoxylon matildense. They corroborate the abundance of Araucariaceae in Late Cretaceous and become the first description of macroflora for the formation.