Coniferophytes from the Bajo de Veliz Formation (Gzhelian-Asselian), San Luis Province, Argentina

Abstract

In this contribution, we analyze the presence of fossil coniferophytes from the Bajo de Veliz Formation (Paganzo Basin) that were initially referred to Walchia or Paranocladus and have not been described until now. These specimens consist mainly of leafy branches exhibiting foliar heteromorphism characteristic of upper Paleozoic coniferophytes from Gondwana. This group includes Genoites sp. with lax arranged ovules on the last order branches, Krauselcladus sp. represented by a small vegetative branch with biand trifurcated leaves, and Buriadia cf. Buriadia heterophylla Seward et Sahni emend. Serbet, Escapa, Taylor, Taylor et Cúneo, 2010, showed axes with multifid leaves and ovules on terminal branches. Vegetative fragments with small lanceolate leaves are assigned to Ferugliocladus cf. F. riojanum Archangelsky et Cúneo, 1987. In addition, an isolated, probably male reproductive structure similar to those known for th latter species was identified. The presence of Buriadia is recognized for the first time in the Carboniferous-Permian of Argentina, as well as the identification of vegetative buds or shoots, a previously undocumented characteristic for this Paleozoic coniferophyte from Gondwana.