Resumen

MARTINEZ, Leandro C.A.  y  LUTZ, Alicia I.. New species of Baieroxylon Greguss and Circoporoxylon Kräusel, in Rayoso and Huincul Formations (Cretaceous), Neuquén Province, Argentina. Ameghiniana [online]. 2007, vol.44, n.3, pp.537-546. ISSN 1851-8044.

Gymnosperm woods from Neuquén Province are studied for the first time. Their xylematic characters allowed distinguish two new species, Baieroxylon patagonicum sp. nov. from the El Mangrullo (Rayoso Formation) and Circoporoxylon krauseli sp. nov. from Cerros Colorados (Huincul Formation). The presence of these two new species increases our knowledge of the xyloflorisctic composition in the area during the Cretaceous. Also, the environmental conditions could be inferred through the analysis of secondary xylem features in which that species grew. Baieroxylon patagonicum sp. nov. probably grew under tropical to subtropical conditions without marked seasons and an abundant hydric regimen while Circoporoxylon krauseli sp. nov. grew under mesophytic conditions.

Palabras clave : Fossil wood; Cretaceous; Rayoso and Huincul Formations; ?Ginkgoales; Podocarpaceae; Neuquén; Argentina.