The medium sized "Arctodus pristinus" and "Tremarctos floridanus" inhabited much of North America in the Early Pleistocene. While a fragmentary "Arctotherium" is first found from El Salvador, the next fossils are of the gigantic "Arctotherium angustidens" in Argentina, from around 1 million years ago. "Arctotherium angustidens" was possibly the largest predatory land mammal ever.