Biodiversidad de las Paleofloras de Patagonia Austral durante el Cretácico Inferior. Asociación Paleontológica Argentina

DEL FUEYO, G.M; VILLAR DE SEOANE, L.; ARCHANGELSKY, A.; GULER, M.V.; LLORENS, M.; ARCHANGELSKY, S.; GAMERRO, J.C.; MUSACCHIO, E.A.; PASSALIA, M.G.; BARREDA, V.

AMEGHINIANA

Estudio Sigma S. R. L

Año: 2007 p. 101 - 122

0002-7014

Abstract. BIODIVERSITY OF THE LOWER CRETACEOUS PALEOFLORA IN SOUTHERN PATAGONIA. A rich and diversevegetation developed in Southern Patagonia during the Lower Cretaceous. Abundant fossil remains havebeen found in different lithostratigraphic units stretching over an extended area that includes Chubut,Santa Cruz and Tierra del Fuego provinces, as well as the southern Magallanes marine platform. The availablepaleobotanical and palynological information is plotted in a floristic chart according to the systematicaffinity of the fossils, as well as their stratigraphical distribution. This unusual paleofloristic richness ispresent throughout most of the entire early cretaceous chronological sequence. Conifers, cycads, bennettites,ferns, lycophytes and bryophytes are well represented while ginkgophytes, seedferns and primitiveangiosperms appear as subordinate groups in these assemblages. The presence of dinoflagellate cysts registersthe first set of recurrent marine floodings of the ancient Atlantic Ocean in southern Patagonia.Important geological and paleontological events (recurrent volcanic activity, extinction, decline or adventof some groups of plants, among others), produced floristic changes that are reflected in the floristic chart.The present day Patagonian flora still has a few relictual taxa of the Lower Cretaceous vegetation.