Nesodon (Greek for "island tooth"); pronounced NAY-so-don
Woodlands of South America
Late Oligocene-Middle Miocene (29-16 million years ago)
Size and Weight:
About 5 to 10 feet long and 200 to 1,000 pounds
Large head; stocky trunk
Named in the mid-19th century by the famous paleontologist Richard Owen, Nesodon was only assigned as a "toxodont"--and thus a close relative of the better-known Toxodon--in 1988. Somewhat confusingly, this South American megafauna mammal comprised three separate species, ranging from sheep-sized to rhinoceros-sized, all of them looking vaguely like a cross between a rhino and a hippopotamus. Like its closest relatives, Nesodon is technically categorized as a "notoungulate," a distinctive breed of hooved mammals that have left no direct living descendants.