the largest perissodactyl, and land mammal, of all time was "palaeoloxodon namadicus". it stood 5.5 m (18 ft) tall at the shoulder, with a total height of 8 m (27 ft). it was 12 m (40 ft) long and may have weighed 20 tonnes (22 tons), though mass estimates vary. some prehistoric horned rhinos also grew to large sizes. the giant woolly rhino "elasmotherium" reached 20 ft long and 6.6 ft high.