Gandolfo, Maria , Cuneo, Nestor .
La Colonia Formation paleoflora (Maastrichtian, Upper Cretaceous), Chubut, Patagonia, Argentina.
In this contribution, we report the presence of a diverse Maastrichtian flora found in sediments of the La Colonia Formation from Chubut, Patagonia, Argentina. The La Colonia Formation outcrops in an area known as the Somuncurá Massif, exposed between Telsen and Sierra Rosada in Chubut province. The formation is a homogeneous series of fining sediments divided into three portions: lower, middle, and upper. Argillaceous sediments characterize the lower and middle portions of the sequence, which is considered to be continental and probably represents lagoonal deposits. The upper portion of the sequence is a marginal to shallow marine environment. A diverse vertebrate fauna, including fishes, turtles, snakes, plesiosaurs, birds, mammals, and dinosaurs are known from the continental facies of the sequence. The fossils we report here were collected at two localities, the Cañadón del Irupé and Cañadón de los Helechos, that are characterized by sediments deposited in a littoral lagoon environment.
Previously, the paleoflora was known from its aquatic ferns (Marsilea, Regnelidium and Paleoazolla), and the angiosperms Nelumbonaceae (leaves and fruits) and Nymphaeaceae (seeds). However, recent paleobotanical collections have revealed the presence of a more diverse plant assemblage associated with these aquatic ferns, including pteridophytes (Dicksonianceae), gymnosperms, and several angiosperms. The angiosperms are represented at least five leaf dicot mophotypes and two monocots morphotytes. These last two probably belong to the Araceae and Typhaceae.
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1 - Cornell University, LH Bailey Hortorium, Department of Pant Biology, 410 Mann Library Biulding, Ithaca, NY, 14853-4301, USA
2 - Museo Paleontológico Egidio Feruglio-CONICET, Av. Fontana 140, Trelew, Chubut, CP9100, Argentina
La Colonia Formation
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Superior A/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 11:45 AM