First record of Tempskya from Mulichinco Formation (Valanginian), Sierra de la Vaca Muerta, Neuquén Basin, Argentina

MARTÍNEZ, LEANDRO C. A.; OLIVO, MARIANA S.; KOPPELHUS, EVA; CORIA, RODOLFO A.

Corrientes

Simposio; XV Simposio Argentino de Paleobotánica y Palinología. II Simposio Argentino de Melisopalinología; 2012

Asociación Paleontológica Argentina y FACENA (UNNE)

The Mulichinco Formation (Valanginian) in Sierra de la Vaca Muerta is mainly a clastic unit of a 50 to 150 meters thick sequence of conglomerates, sandstones and claystones that represents terrestrial to shallow marine deposits of a low-frequency lowstand wedge. Some of the sandstones are fluvial in origin and contain coniferous fossil woods and false trunks of Tempskya, associated with dinosaur remains. False trunks of Tempskya are described from the Mulichinco Formation in Neuquén province, Argentina. They are silicified and consist of a system of solenostelic stems, dichotomously branching, and surrounded by a dense mat of adventitious roots. The genus Tempskya is an extinct fern preserved as permineralized false-trunks, with a global distribution during the Early Cretaceous. However, the records in the Southern Hemisphere are scarce, and restricted to the Rayoso Formation (Aptian - Albian, Neuquén Province, Argentina) and the Winton Formation (Albian, Queensland, Australia). This evidence from the Valanginian of Patagonia would represent the oldest record of Tempskya. The presence of this genus implies humid and warm climatic conditions during the deposition of the Mulichinco Formation.