INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
The most ancient Platyperlidae (Insecta, Perlida= Plecoptera) from early Late Triassic deposits in southern South America
GALLEGO, O.F., RÉBORI, L.O., ZAVATTIERI, A.M., SINITSHENKOVA, N., LARA. M.B AND MARTINS-NETO, R.G.
ASOCIACION PALEONTOLOGICA ARGENTINA
Lugar: Buenos Aires; Año: 2011 p. 447 - 447
The new insect species Platyperla marquati sp. nov. described herein is represented by a nymphal stage and belongs to the Order Perlida (= Plecoptera) Latreille (stoneflies). It comes from the uppermost section of the Potrerillos Formation, which crops out south of Cerro Cacheuta, at the southernmost end of the Precordillera (Mendoza Province, Argentina). The early Late Triassic Potrerillos/Cacheuta sedimentary succession in this area includes fluvial, deltaic and lacustrine facies that reflect deposition in the border of the Cacheuta depocenter of the Cuyo Basin. This is the second complete insect and the first autochthonous aquatic insect from Triassic beds in Argentina, and also the first record of the family Platyperlidae in Gondwana. This finding demonstrates the similarity of aquatic insect faunas in Mesozoic deposits all over the world, at least of the morpho-ecological types of the aquatic stages. The lacustrine insect fauna began evolving during the Triassic and became diverse during the Jurassic and Early Cretaceous. Detailed geological studies revealed that levels equivalent to the middle Triassic lower units of the Uspallata Group (Río Mendoza and Cerro de Las Cabras formations) lie exposed on the southeastern flank of Cerro Cacheuta. Therefore, a new geological map and interpretation for this area are also presented.