Hyrachyus (Greek for "hyrax-like"); pronounced HI-rah-KAI-uss
Plains of North America
Middle Eocene (40 million years ago)
Size and Weight:
About 3-5 feet long and 100-200 pounds
Medium size; muscular upper lip
You may never have given the matter much thought, but modern-day rhinoceroses are most closely related to tapirs--pig-like ungulates with flexible, elephant-trunk-like upper lips (tapirs are famous for their cameo appearance as "prehistoric" beasts in Stanley Kubrick's movie 2001: A Space Odyssey). As far as paleontologists can tell, the 40-million-year-old Hyrachus was ancestral to both these creatures, with rhino-like teeth and the barest beginnings of a prehensile upper lip. Oddly enough, considering its descendants, this megafauna mammal was named after an entirely different (and even more obscure) modern creature, the hyrax.