Hidden termite coprolites revealed by Synchrotron microtomography inside Eocene-Oligocene filled wood-borings from the Malzieu Basin, Lozere, southern France

Fragments of filled wood-borings were recently discovered from the Eocene-Oligocene Conglomerate and Sandstone Formation of the Malzieu Basin (Lozere, southern France). Propagation phase-contrast X-ray synchrotron microtomography (PPC-SR mu CT) was used to characterize their hidden inner structures. Virtual 2D sections and 3D reconstructions show that the inner microstructures of borings display a mudstone-wackestone siliceous matrix including tiny coprolites. The hexagonal cross-section of these coprolites is characteristic of termite faecal pellets. Morphology and dimensions of the coprolites share strong similarities with those of extant Kalotermitidae (drywood termites). The depositional environment is interpreted as a fluvial valley in which the lenticular sandstone and conglomerate lenses correspond to channels. This discovery complements the record of Palaeogene termites which remain poor in France and throughout the world.