Among the other 11, south Africa has a critical role to play as it is more developed than the others, and also somewhat of a gateway to southern Africa.
By improving their hunting techniques, early humans seem to have played a major role in finishing off the woolly mammoths and nine other mammal species that weighed over a tonne.
There is a throng of institutions in the old social order, which one comes across in this fashion as one walks about outdoors, and which have no other reasons for existence than the above.
Several other mass extinctions in the geological record have been tentatively identified with large impacts, but none is so dramatic as the Cretaceous event.