| In the Bermejo Basin, the Los Rastros Formation bears an abundant insect fauna, mainly of terrestrial winged adult organisms related to the Blattoptera and the Coleoptera orders. The insect remains are found in the black shales of the offshore lacustrine facies and their taphonomic features suggest that the specimens were allochthonous to the lake. The individuals appear to arrived alive to the lake and had a rapid fall trough the water column, thus, they are preserved intact. In contrast, some of them may have suffered fragmentation in air traspontation and/or biological attack during long periods of flotation. |
