FOSSIL FLORA FROM THE PENNSYLVANIAN OF SIERRA DE LOS LLANOS, LA RIOJA, ARGENTINA.

FOSSIL FLORA FROM THE PENNSYLVANIAN OF SIERRA DE LOS LLANOS, LA RIOJA. ARGENTINA. Fossil plant assemblages from the Pennsylvanian of Sierra de Los Llanos range, La Rioja Province, are described ill this contribution. They come from the La Huerta and Santa Barbara Sections, Cropping out in the northeastern flank of the Sierra de Los Llanos range. La Huerta section, referred to the Solca Formation. yielded a diverse macrofossil assemblage composed by conifers (Paranocladus? fallax Florin), dispersed seeds (Samaropsis munezii Garcia emend. A. Archangelsky, Eucerospermun nitens Feruglio emend. A. Archangelsky), cordaitals [Cordaites sp. ef. C. hislopi(Bunbury) Seward], lycophytes (ef. Bumbudendron vermiforme Gutierrez et al.) and pteridosperms (Eusphenopteris sp.). This assemblage is provisionally referred to the Megafloristic Interval Biozone, latest Carboniferorus in age. Santa Barbara section, assigned to the lower Loma Larga Formation, yielded remains of the lycophyte ef. B. versiforme. This assemblage is referred to the NBG Biozone (Nothorhacopteris argentinica-Botrychiopsis weissiana-Gynkgophyllum diazii) that characterizes the Pennsylvanian of western Argentina.