Evans et al. (2021) seem to have been well aware of the circular reasoning in their argument.
The new fossils stem from a layer in the Nama Group of Namibia, just below an ash bed that could be radiometrically dated to 547.32 ± 0.65 million years.
One researchers has preferred to classify Kimberella among the Ediacaran “fossil problematica.”
The body fossils are generally positioned at the focal points of the fan-shaped scratch marks.
The claim that a spike in carbon isotope concentrations led to the explosion of biological diversity in the Cambrian doesn’t hold up, as if it would have helped, anyway.