indicates that mammals existed long before the strike and their diversification and prosperity started much later, probably due to global warming that seems to be highly beneficial for mammal life, in a sharp contradiction with one of the statements of the environmentalists.
Figure 1: The echidna, one of the oldest mammals
Recall that the earlier expansion of dinosaurs themselves - after the Great Dying 250 million years ago - is another event where it's not quite clear whether the climate or a celestial body was responsible for the abrupt developments.
