Comment on “Discussion: Extracting thermal history from low temperature thermochronology/A comment on the recent exchanges between Vermeesch and Tian and Gallagher and Ketcham”, by Paul Green and Ian Duddy, Earth Science Reviews, https://doi.org/10.1016/j.earscirev.2020.103197

The discovery in the 1980's that DNA could be extracted and sequenced from extinct animals opened-up a whole new area of research paleobiology. oldest authenticated sequence ever recovered is between 1.65 1.1 million years (My) old extrapolation models on degradation suggest this close to temporal limit survival. However, recent data cell nuclei 30 80 My-old fossil cells plants dinosaurs show positive staining with standard stains fluorochromes. We heavily discuss scrutinize results these studies argue intracellular stainings seen Cenozoic Cretaceous fossils are consistent presence endogenous inconsistent contamination. Properties preserved molecules made at least sugar-phosphate backbone DNA, some instances they may double stranded base pairs. Previous works damage also material crosslinked filled chemically modified nucleotides, which explain why it apparently not PCR-amplifiable nor sequenceable form.However, even though many questions remain, cannot yet ruled out retrieving ancient sequences older than Pleistocene will possible future. Here, we summarize reassess all current evidence propose methods ideas how further understand preservation deep time. Notably, microscopy-based sequencing offer most promising results. main goal review need for collaborations fields Ancient Molecular Paleontology Paleohistology better seek truth about fossilization.