Although horses were domesticated several millennia ago, there are a lot of misconceptions about their evolutionary history.? Bruce MacFadden from the University of Florida sets the record straight in a recent issue of the journal Science:

Horses have not simply evolved to be bigger.? About 20 million years ago, horses diversified in size - some became larger, while others shrunk to the size of dogs.

Primitive horses were not primarily leaf-eating browsers.? They were adaptable creatures that foraged on both grasses and leafy material when necessary.

The first horses in North America were not brought by European settlers.? The continent's horse fossils date from 55 million years ago to 10,000 years ago - when the native species went extinct.

A clear understanding of this fossil record is important, MacFadden said, since horses are often used in textbooks and museums to illustrate evolution.