At http://phys.org/print394781614.html … Russian palaeontologists investigating a mammoth graveyard in the Novosibirsk regions, recognised as one of the largest assemblages in Eurasia, were astounded at how deep the grave goes (both young and old animals) and they are far from coming to the bottom. The deeper levels of broken bones were covered in a layer of sand and clays – but the cause of death of so many animals is unknown. It is thought a landslide of some kind buried thousands of animals – including bison, horse and many smaller mammals.
Meanwhile, at http://phys.org/print394781775.html .. a palaeontologist from the University of Hawaii is questioning the level of extinction at the Permian-Triassic boundary. It sounds a bit like picking at the pieces without looking at the whole event as the mainstream position (cast almost in stone) is that 96 per cent of marine life perished. The new assessment is that just 81 per cent died out. In the grand scheme of things very little has changed.