AROUND 66m years ago Earth collided with a space rock so large that it punched a crater more than 180km across in the area now known as the Yucatán peninsula, in southern Mexico. This collision did for the dinosaurs and many other sorts of animal besides. It thus wiped much of the ecological slate clean, permitting the survivors—those that did not, as it were, croak in the impact’s aftermath—to strut their evolutionary stuff unconstrained.
Human beings, with phylocentric arrogance, often refer to the subsequent period, extending to the present day, as the “Age of Mammals”—and it is true that mammals have done well in it. At the moment, zoologists recognise about 5,400 species of this hairy, milk-secreting group of creatures. But another sort of terrestrial vertebrate has done better even than this, with almost 6,800 living species. It might be at least as fair to call the post-dinosaur world the “Age of...Continue reading
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