Ex. Tinc. Tion.

From this great New Yorker article about the search for a general theory of extinctions (hint: we may be contributing to the current one – shocking, I know…)

It is difficult to say when, exactly, the current extinction event – sometimes called the sixth extinction – began. What might be thought of as its opening phase appears to have started about fifty thousand years ago. At that time, Australia was home to a fantastic assortment of enormous animals; these included a wombatlike creature the size of a hippo, a land tortoise nearly as big as a VW beetle, and the giant short-faced kangaroo, which grew to be ten feet tall. Then all of the continent’s largest animals disappeared. Every species of marsupial weighing more than two hundred pounds – and there were nineteen of the – vanished….This die-off roughly coincided with the arrival of the first people on the continent, probably from Southeast Asia.