Gymnosperm woods from the Carapacha Formation (Permian), La Pampa Province, Argentina.

This paper describes four gymnosperms woods from the fluvial-lacustrine Carapacha Formation (Early Permian to early Late Permian) of La Pampa, Argentina. All the material was preserved as driftwood in sandstone channel facies (mineralized by carbonates or silica) and associated with a Glossopteris flora. One specimen is referred to Schofiicaulia peripaludica Mussa on account of the anatomical characters of the pith, and primary and secondary xylem. Only secondary xylem is present in the remaining woods and therefore they are assigned to three Araucariozylon species: A. allanii (Krausel) Maheshwari, A. kharhariense (Maithy) Maheshwari and A, jamudhiense (Maithy) Maheshwari. In the analyzed material there is anatomical evidence of humidity shortage during the life of these plants, which is in agreement with the sedimentologic interpretation of the sedimentary sequence. These species were also recorded in the Permian of Brazil, Antarctica, and India.