Biodiversidad de las Paleofloras de Patagonia Austral durante el Cretácico Inferior

GEORGINA M. DEL FUEYO; LILIANA VILLAR DE SEOANE; ANA ARCHANGELSKY; VERÓNICA GULER; MAGDALENA LLORENS; SERGIO ARCHANGELSKY; JUAN CARLOS GAMERRO; EDUARDO A. MUSACCHIO; MAURO G. PASSALIA; VIVIANA D. BARREDA

PUBLICACION ESPECIAL - ASOCIACION PALEONTOLOGICA ARGENTINA

Talleres Gráficos del Instituto Salesiano de Artes Gráficas

Año: 2007 vol. 11 p. 101 - 122

0328-347X

Abstract. Biodiversity of the Lower Cretaceous paleoflora in Southern Patagonia. A rich and diverse vegetation developed in Southern Patagonia during the Lower Cretaceous. Abundant fossil remains have been 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 available paleobotanical and palynological information is plotted in a floristic chart according to the systematic affinity of the fossils, as well as their stratigraphical distribution. This unusual paleofloristic richness is present throughout most of the entire early cretaceous chronological sequence. Conifers, cycads, bennettites, ferns, lycophytes and bryophytes are well represented while ginkgophytes, seedferns and primitive angiosperms appear as subordinate groups in these assemblages. The presence of dinoflagellate cysts registers the 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 advent of 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.