Ecological interactions of sauropods and arthropods during the Upper Cretaceous of the Neuquén Basin

C.A. PIRRONE

San Rafael, Mendoza, Argentina

Jornada; XXIV Jornadas Argentinas de Paleontología de Vertebrados; 2009

Museo de Historia Natural de San Rafael. Asociación Paleontológica Argentina

Ecological interactions of sauropods and arthropods during the Upper Cretaceous of the Neuquén Basin.   C. A. PIRRONE 1, 2   Bioerosion traces exhibited on fossil tetrapod bones are analyzed as evidence of ecological interspecific relations between large herbivorous vertebrates and arthropods. These evidences of paleoecological interactions during the Mesozoic have been reported in many localities of the world, but there is no detailed studies developed in Argentina. Only brief mentions of bioerosion traces had been made from strata of the Upper Cretaceous of the Neuquén Basin. The type of fossil traces described here are the first ones reported in Argentina. They were found on fragmentary bones of sauropod dinosaurs (IANIGLA-PV 150/ 1-4 ) collected between 2004 and 2006 in two different localities at the northeastern limit of the Neuquén Basin (late Turonian – early Maastrichtian), in Mendoza Province. Traces were observed by examination with low angle, high intensity light sources. This communication includes preliminary description of shallow bores (surficial parallel sided excavation, depth <5 mm) and bores (tunnel-like, deep bore, length >5 mm) interpreted as feeding activity of osteophagus arthropods, as well as its similarity with materials from other parts of the world. From comparison of these fossil traces with actual necrophagus insects ethology, the ecological role of large tetrapods in ecosystems at first stages of decomposition after death is re-evaluated. Relations of paleoenvironmental conditions with analysis of bioerosion traces on bones is proposed as a methodological tool for understanding trophic relations and structure of food webs during the Upper Cretaceous of the Neuquén Basin, but also as useful additional data for reconstructing continental ecosystems paleoecology. Study supported by ANPCYT-PICT-33984.   1 IANIGLA – CCT-Mendoza – CONICET. Departamento de Geología y Paleontología, Av. Ruiz Leal s/n, Parque Gral. San Martín (5500) Mendoza, Argentina. cpirrone@mendoza-conicet.gov.ar 2 Instituto de Ciencias Básicas, Univ. Nacional de Cuyo, Mendoza, Argentina.