Re: Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary
Here I cite: ‘Mass extinctions manifest in Earth’s geologic record were turning points in biotic evolution. We present 40Ar/39Ar data that establish synchrony between the Cretaceous-Paleogene boundary and associated mass extinctions with the Chicxulub bolide impact to within 32,000 years. Perturbation of the atmospheric carbon cycle at the boundary likely lasted less than 5000 years, exhibiting a recovery time scale two to three orders of magnitude shorter than that of the major ocean basins. Low-diversity mammalian fauna in the western Williston Basin persisted for as little as 20,000 years after the impact. The Chicxulub impact likely triggered a state shift of ecosystems already under near-critical stress.’
When reading the abstract, one would await at least one photo linking the obtained data and the fossilized mammalian fauna in the strata. There are no photos and thus we can easily conclude that the 65/66 Ma events do not belong to the fossils. The fossils may be much more younger with their fossilization at the 65/66 Ma basements. Each scientific paper operating with dating of mass extinction events has to provide a clear link.