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Here we report on Neanderthal engravings on a cave wall at La Roche-Cotard (LRC) in central France, made more than 57±3 thousand years ago. Following human occupation, the cave was completely sealed by cold-period sediments, which prevented access until its discovery in the 19th century and first excavation in the early 20th century. The timing of the closure of the cave is based on 50 optically stimulated luminescence ages derived from sediment collected inside and from around the cave. The anthropogenic origin of the spatially-structured, non-figurative marks found within the cave is confirmed using taphonomic, traceological and experimental evidence. Cave closure occurred significantly before the regional arrival of H. sapiens, and all artefacts from within the cave are typical Mousterian lithics; in Western Europe these are uniquely attributed to H. neanderthalensis. We conclude that the LRC engravings are unambiguous examples of Neanderthal abstract design. [ABSTRACT FROM AUTHOR]

Using three different microscopy techniques (epifluorescence, electronic and atomic force microscopy), we showed that high-Mg calcite grains in calcifying microbial mats from the hypersaline lake “La Salada de Chiprana”, Spain, contain viruses with a diameter of 50–80 nm. Energy-dispersive X-ray spectrometer analysis revealed that they contain nitrogen and phosphorus in a molar ratio of ~9, which is typical for viruses. Nucleic acid staining revealed that they contain DNA or RNA. As characteristic for hypersaline environments, the concentrations of free and attached viruses were high (>1010 viruses per g of mat). In addition, we showed that acid treatment (dissolution of calcite) resulted in release of viruses into suspension and estimated that there were ~15 × 109 viruses per g of calcite. We suggest that virus-mineral interactions are one of the possible ways for the formation of nano-sized structures often described as “nanobacteria” and that viruses may play a role in initiating calcification. [ABSTRACT FROM AUTHOR]