Southern beech (Nothofagaceae) fossil leaves from the Río Turbio Formation (Eocene?? Oligocene), Santa Cruz Province, Argentina

CAROLINA PANTI

Revista del Museo de Ciencias Naturales n.s.

Museo Argentino de Ciencias Naturales Bernardino Rivadavia e Instituto Nacional de Investigación de las Ciencias Naturales

Lugar: Ciudad de Buenos Aires; Año: 2019 vol. 21 p. 69 - 85

1514-5158

Nothofagus sp. cf. N. obliqua, Nothofagus sp. aff. Nothofagus alessandri and Nothofagus magelhaenica are reported for the first time for the Paleogene Río Turbio Formation along with another five fossilspecies: Nothofagus simplicidens, Nothofagus variabilis, Nothofagus lanceolata, Nothofagus subferruginea andNothofagus dicksonii. Around one hundred specimens of fossil leaves were recorded and analysed throughout theunit, but they are fairly more abundant in the upper member of the Río Turbio Formation where they reach 68%of the overall assemblage. The observed increasing trend in Nothofagus abundance throughout the unit coincideswith the beginning of the flora turnover that characterized Patagonian ecosystems from the Late Eocene onwardsand it is in agreement with the marked global cooling trend of the terminal Paleogene.