Fossil Odonata of Argentina through body fossils and endophytic ovipositions

PETRULEVICIUS, JULIAN; ROMERO LEBRÓN, M. E.

La Plata

Congreso; international congress of odonatology 2015; 2015

Fossil Odonata in Argentina are recorded from the Triassic to the Paleogene. They are represented by body fossils of nymphs and imagines, and traces. They were nearly unknown before the latest years of the last century, because of the historical lack of paleoentomologists and of collections of fossil insects in the Country. From the last decade until today a nice fauna represented by new taxa up to family level was discovered in the Paleocene and Eocene of Argentina. These fossils belong to all major groups of Odonata, Palaeomacromiidae (derived Anisoptera), Frenguelliidae (basal Epiproctophora), Latibasaliidae (Caloptera) and Austroperilestidae (Euzygoptera). The Palaeomacromiidae are italoansids basal to Libellulida found in the late Paleocene of Northwest Argentina. Later, they were found in the Eocene of Monte Bolca, Italy, showing a wider distribution and a probable Cretaceous history. The amphipterygoid family Latibasaliidae, also found in the Northwest, has two described species. The Frenguelliidae are considered basal Epiproctophora, which have a cryptic history from the Triassic, reappearing in the Miocene (Sieblosiidae) and Recent (Epiophlebiidae). The eulestiformian family Austroperilestidae is found as the Frenguelliidae in the Eocene of Patagonia. It seems to be related to the Afro-South American family Perilestidae. There are other three genera from the Northwest, Jujusia and Austrolibellula whose relationships with the italoansids are unknown, and Palaeophya, related to African Neophyinae. There are also two species of Aeshnidae from the Eocene, probably related to Oligaeshna, one from the Northwest and the other from Patagonia. Nymphs are restricted to the Eocene of Patagonia and attributable to Synlestidae, Libellulidae, and Gomphidae. Older Odonata are nearly unknown with only two species, a Triassolestidae from the Triassic of Mendoza belonging to a genus with two South African species, and Argentinopetala, a Petaluridae from the Cretaceous of Patagonia. Ovipositions of Odonata are recorded in the Cretaceous and Eocene of Patagonia and are related to leaves of angiosperms associated to water. Of course, until now there are few species discovered to give definite conclusions on the Odonata fauna, but it appears that it is a highly specialised one with a high level of endemism.