A new paleoentomofauna from the Late Triassic (Norian) of the Malargüe Basin, Mendoza Province, Argentina

GALLEGO, O.F.; MARTINS-NETO, R.G.; BRAUCKMANN, C.; HAUSCHKE, N.; LARA, M.B.; GROENING, E.; ILGER, J.-M.

Buenos Aires

Otro; Reunión Anual de Comunicaciones de la Asociación Paleontológica Argentina, 2009; 2009

Asociación Paleontológica Argentina

Late Middle Triassic to early Late Triassic insects from Argentina have been previously described from the Bermejo and Cuyana Basins where have been recovered from the Ischichuca–Los Rastros and Potrerillos–Cacheuta Formations respectively. The insect fauna discussed herein was collected during field studies in 1986/87 from the Llantenes Section (Norian, Late Triassic), which is situated in the Malargüe Basin in southern Mendoza Province. The insect remains were found in the upper part of the Llantenes Section (Llantenes Formation), which is build up of two coarsening upwards sequences reflecting a deltaic progradation of a fluvial into a lacustrine environment (lower part) succeeded by repeated progradations into a floodplain-dominated environment (upper part; with finds of insects, conchostracans, fish remains, plant fragments and drifted logs). The collected fossils will be deposited in the Paleoinvertebrate Collection (MCNAM–PI) of the Museo de Ciencias Naturales y Antropológicas “Juan Cornelio Moyano”, Mendoza city, Argentina. The new finds represent the youngest described Triassic insect records from Argentina, and even from entire South America. There is only one other contemporaneous fossil assemblage in Gondwana: in the Clarence/Moreton Basin (Aberdare Conglomerate; Late Norian) in Australia. The new Triassic insects include an impression of an isolated mecopteroid wing, coleopteran elytra of the Permosynidae (probably Ademosyne punctuada Martins-Neto and Gallego, as previously reported from the Los Rastros Formation) and other isolated body fragments. With this new record the diversity of Late Triassic entomofaunas and the knowledge of the biotic recovery after the P/T event are increased.