Nuevos hallazgos de leños con anatomía preservada en el Carbonífero Superior de la provincia de San Juan, Argentina

Resumen

Recent discoveries of permineralized wood from the Upper Carboniferous of San Juan province allow us to increase the scarce record inArgentina. The studied material comes from quebrada dela Mina(Jejenes Formation) and Barreal (Hoyada Verde Formation) localities. In both cases they are associated to the NBG flora that includes, pteridosperms, cordaites and sphenopsids. The specimens from the Jejenes Formation are up to14 cmin diameter and are very well preserved, usually with the pith conserved. They are pycnoxylic, homoxylic, with distinctive growth rings, homogenous pith and mesarc protoxylem. The specimens from Barreal, have pycnoxylic secondary xylem, tracheids with biseriate to multiseriate rounded pits and homogeneous rays with short cells. They are both compared with different species from the Upper Paleozoic and it is analysed their relation with the plants groups represented in the associated flora.