straight from the ……

small_horse

After they first appeared in the fossil record, horses got smaller as a result of a warming planet, says a study just published in Science.

“Horses started out small, about the size of a small dog like a miniature schnauzer,” said co-author Jonathan Bloch, associate curator of vertebrate paleontology at the Florida Museum of Natural History on the UF campus.

“What’s surprising is that after they first appeared, they then became even smaller and then dramatically increased in size, and that exactly corresponds to the global warming event, followed by cooling.”

“It had been known that mammals were small during that time and that it was warm, but we hadn’t understood that temperature specifically was driving the evolution of body size.”

Grist, 23 Feb 2012