a long-necked, long-legged, fossil mammal, Indricotherium transouralicum, related to the rhinoceros and existing 10 to 30 million years ago, possibly the largest and heaviest land mammal.
in·dri·co·there (ĭn'drə-kō-thîr') n. A very large extinct land mammal (Indricotherium transouralicum) of the Oligocene and Miocene epochs, related to the rhinoceros and characterized by a long neck. It is thought to be the largest and heaviest land mammal, with an estimated height up to 5.2 meters (17 feet) and weight up to 15,750 kilograms (35,000 pounds).
[New Latin Indricothērium, genus name : Russian indrik, fabulous beast in Russian folklore (probably from alteration of Old Russian inŭrogŭ, unicorn : inŭ, one; see oi-no- in Indo-European roots + rogŭ, horn) + Greek thērion, wild beast; see treacle.]