Notes about diversity and biogeography of Odonata and Mecoptera of Paleogene of Argentina.

PETRULEVICIUS, J. F.

Bonn

Congreso; III Bonner Paläoentomolgen-Treffen. Institut für Paläontologie der Universität Bonn; 2006

Fossil Odonata from Argentina were unknown from latest years of the last century. This diversity was clearly biased due to the historical lack of paleoentomologists in the Country; also unrepresented by the lack of collections of fossil insects. Since last decade to the moment an extraordinary fauna represented by new taxa from family to species level was discovered. Fossils belong to all mayor groups of Odonata, the Anisoptera Palaeomacromiidae, the basal Epiproctophora Frengueliidae, the Caloptera Latibasaliidae and the Euzygoptera Austroperilestidae. The Palaeomacromiidae are italoansids basal to Libellulida and found in the late Paleocene of Northwestern Argentina. More recently this family was found in the Eocene of Monte Bolca in Italy, showing a wider distribution and a probable Cretaceous history for the group. This family has at present three genera and five species. The amphipterygoid family Latibasaliidae is also found in Maíz Gordo strata and have two described species. The Frengueliidae are considered basal Epiproctophora with a cryptic history from the Triassic as also present in Miocene Sieblosiidae and Recent Epiophlebiidae. The eulestiformian family Austroperilestidae is found as Frengueliidae in the Eocene of Laguna del Hunco in argentinean Patagonia. It seems to be related to the Afro-South American family Perilestidae. Frengueliidae and Austroperilestidae are for the moment monotypic families. There are other two genera from Maíz Gordo strata, Jujusia and Austrolibellula whose relationships with the italoansid families are unknown. There are also other fragmentary preserved specimens of Aeshnidae in Northwest and Patagonia, probably related to genus Oligaeshna. Of course, until now there are few specimens discovered to give definite conclusions on this Odonata fauna, but it appears that it is a highly specialised one. Further investigation will give information on the Odonata paleobiodiversity at the Cretaceous / Paleocene boundary.