megaterio . ( Of mega - and the Gr. ?, beast). 1. m. mammal of the order of the Desdentados, fossil, about six meters in length and two tall, with bones more robust than the of the elephant, relatively small, without teeth or tusks and head with only four teeth on each side of the jaws, very thick body, short legs, great feet, with fingers armed nails strong and scream, and tail of half a meter in diameter in his boot. He lived in South America at the beginning of the Quaternary period, and their diet was herbivorous, as evidenced by his teeth. The main skeletons of this animal are preserved in museums come from the Argentine pampas.