Abstract

GANDOLFO, María A.; CUNEO, N. Ruben  and  HERMSEN, Elizabeth J.. Preliminary report on the paleoflora of the La Colonia formation (Campanian-Maastrichtian, late Cretaceous), Chubut, Patagonia, Argentina. Bol. Soc. Geol. Mex [online]. 2014, vol.66, n.1, pp.11-23. ISSN 1405-3322.

In this contribution, we present new paleofloristic elements from the La Colonia Formation (Campanian-Maastrichtian, Late Cretaceous), exposed between Telsen and Sierra Rosada in the area known as the North Patagonian Massif, Chubut, Patagonia, Argentina. Previously, the paleoflora was only known from some of its aquatic components: pteridophytes representing the families Salviniaceae and Marsileaceae and angiosperms representing the families Nelumbonaceae. However, recent paleobotanical collections have revealed the presence of a more diverse plant assemblage including other aquatic elements as well as terrestrial ferns, conifers, and several angiosperms. Among the aquatics, macrofossils similar to Azolla (pteridophyte), and two angiosperms related to the families Araceae and Typhaceae are described; while the terrestial components are represented by fossils of Dicksonianceae (pteridophyten), a putative araucariacean conifer, and six dicot morphotypes. The aquatic elements are intepreted as autochtonous and the terrestial as allochtonous. The taphocenosis confirms the environmental interpretation previously suggested for the middle sector of the La Colonia Formation.

Keywords : Argentina; Late Cretaceous; La Colonia Formation; paleoecology; paleoflora.

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