First South American record of fossil Lygaeoidea

PETRULEVICIUS, J. F. Y COSCARÓN, M. DEL C..

Foz do Iguaçu

Congreso; XXI International Congress of Entomology; 2000

Lygaeoidea are rare in the fossil record, there are about 51 extinct genera, against 500 living genera and 4000 species. They come from the Lower and Upper Jurassic of China, Jurassic of Kazakhstan, Cretaceous of Mongolia and China, Eocene of USA, Oligocene of Europe and USA, Miocene of Europe, and Pliocene of Germany. The specimen was collected from the late Paleocene-lower Eocene Maíz Gordo Formation, composed by green mudstone and shale (24° 21´ S; 64° 59´ W), Northwest Argentina. Terrestrial Heteroptera are well represented in this assemblage (about 6.2 % of 390 insects recovered from a preliminary study). All specimens excepting that of the present communication are represented by isolated hemelytra. At present there is no record of aquatic true bugs. The Lygaeoidea is a nearly complete, laterally compressed, female specimen. One hemelytra is also preserved. The specimen has two of the synapomorphies of Lygaeoidea sensu Henry 1997 , i.e. 3-5 simple veins in hemelytral membrane; fore femora incrassate. Trichobotrial pads, the third synapomorphy of Lygaeoidea, may be not preserved. The specimen shares with the monophyletic group formed by ((Heterogastrinae+Pachygrontinae)+ (Plinthisini+Ryparochromini)) the presence of ventral laterotergites. Other synapomorphies of last group are not preserved. Relationships within this group remain dubious and uncertain because of the lack or the difficult interpretation of some characters. Index terms: Lygaeoidea, Paleogene, South America.