First fossil darkling beetles assemblage (Coleoptera: Tenebrionidae) from the late Pleistocene of Buenos Aires, Argentina

RAMÍREZ LEONARDO; CARRARA RODOLFO; SILVESTRO, VIOLETA A.; FLORES GUSTAVO ERNESTO

Mendoza

Simposio; Fourth International Tenebrionoidea Symposium; 2015

Late Pleistocene outcrops exposed in Buenos Aires province, Argentina,represent one of the most informative sources for paleoecologicalstudies on South American fauna and flora. Several proxies wereutilized for the study of pleistocene environmental conditions in thePampas, but only a few were based on paleoentomological data. Theaim of this study is to present the first record of three species of darklingbeetles from the Late Pleistocene of Buenos Aires province, and toprovide new paleoenvironmental. The sediments containing fossilinsects correspond to the Guerrero Member of the Luján Formationand where dated between 12,100 ± 100 14C BP and 13,400 ± 200 14CBP. During the extraction and concentration of fossil insects we avoidthe kerosene flotation and the sieving in order to maintain the material suitable for radiocarbon dating and prevent breakage. We identifiedspecimens of Nyctelia picipes (Billberg), Epipedonota cristallisata(Lacordaire) (Pimeliinae: Nycteliini) and Scotobius pilularius Germar(Tenebrioninae: Scotobiini). By analyzing the particular environmentalrequirements of these species and the use of the MCR method, wecould infer values of temperature and other relevant climatic aspects.This association could show us the first pulses of post-glacial climaterecovery and the replacement by the insect fauna that currently inhabitthe area. This study is one of the first approaches to the quaternarypaleoentomology of Argentina, and highlights the potential ofpaleoentomological information, when evaluated in combination withprevious knowledge on global climate conditions after the last glacialmaximum