Haplomastodon
laelaps | April 20, 2010
For much of the past 130 million years South America was an island continent, and on it organisms evolved in "splendid isolation." Mammals, especially, evolved into forms not seen anywhere else, and while some mammalian immigrants made their way to South America during the past 30 million years it was not until about three million years ago, with the closing of the isthmus of Panama, that large animals from North and South America began to wander across the new landbridge and mix with the endemic faunas. This is why there were elephants in South America and giant ground sloths in North…