Toxodon is an extinct mammal of the late Pliocene and Pleistocene epochs about 2.6 million to 16,500 years ago, Indigenous to South America it was probably the most common large-hoofed mammal in South America at the time of its existence. Charles Darwin was one of the first to collect Toxodon fossils, after paying 18 pence for a T. platensis skull from a farmer in Uruguay. Since Darwin discovered that the fossils of similar mammals of South America were different than those in Europe, he invoked many debates about the evolution and natural selection of animals.