Fifty to 60 million years ago, the prehistoric ancestors of elephants roamed every land mass in the world except Australia and Antarctica. Today, all but two members of the Elephantidae family of the order Probiscidea, meaning animals with trunks, have survived -- African and Asian elephants. For long periods of history, humans coexisted on the planet with mastodons, mammoths and some of the more primitive relatives of modern-day elephants. Many paleontologists believe that over-hunting could have contributed to the disappearance of some species that might otherwise have been able to recover after the Ice Age of about 11,000 years ago, when almost all North American mammals weighing more than 100 pounds became extinct.
Even though Moeritheres looked more like hippos and tapirs than elephants, these semi-aquatic animals originating in northern Africa 55 to 60 million years ago were among the earliest ancestors of our present-day pachyderms. They didn't have a trunk but their muscular, mobile upper lip served a similar purpose, allowing them to grasp and uproot freshwater plants; instead of tusks, they had two large incisors protruding downwards from their mouths. Since no complete skeletons have yet been found, size estimates for these prehistoric animals vary, but the fossil evidence suggests that they weren't much larger than present-day pigs, the Elephant Information Repository website reports.
About 40 to 25 million years ago, the mastodon, which resembled the modern-day elephant, emerged on the prehistoric scene. Members of the mastodon family were distributed all over the world, but for millions of years the American mastodon ranged from Alaska to central Mexico, finally becoming extinct about 13,000 years ago. Although smaller than a mammoth, the mastodon was about the same size as an African elephant. Tipping the scales at as much as 6 tons, male mammoths measured about 10 feet, females 7 feet, at the shoulder. Mastodon remains have been excavated in National City and Oceanside, both in San Diego County, California. In ancient times, mammoths and mastodons coexisted in North America, but ate different kinds of vegetation so they probably did not come into conflict.
Gomphotheres and Stegodon
Artists' impressions of the Gomphotheres, some of the elephant's strangest-looking ancestors, make you wonder how these animals managed to eat with four tusks crowding their mouths. Some members of this family, widespread in Florida, even had a mouth shaped more like a duck's bill than an elephant's trunk. Gomphotheres are thought to be the ancestors of the Stegodon, a large elephant-like animal assumed to have been an excellent swimmer, since fossilized remains have been found on islands as well as the mainland in Asia and Africa. In 2004, Australian and Indonesian researchers discovered the 18,000-year-old bones of a tiny human species, nicknamed "hobbits," in a cave on Flores, an island east of Bali, midway between Australia and Asia, and with them the bones of dwarf Stegodons they apparently hunted for food.
Superficially, African and Asian elephants strongly resemble each other, but in fact the Asian elephant is more closely related to the mammoth than to its African counterpart. On average, mammoths measured 10 to 13 feet at the shoulder, weighed up to 9 tons and sported long, curving tusks about 16 feet in length. The long, shaggy hair that covered the bodies of woolly mammoths helped them stay warm during the Ice Age, when most other species of large mammals faded into extinction. Most woolly mammoth species also died off about 7,600 years ago, but a small population managed to survive on Russia's Wrangel Island in the Arctic Ocean until about 3,800 years ago, their tissues preserved well enough in the frigid temperatures to yield viable DNA. Using this, in 2012 Russian and Japanese scientists embarked upon a highly controversial project to produce a mammoth-elephant hybrid.
- Elephant Information Repository: Evolution
- Prehistoric Wildlife: Moeritherium
- University of Oxford: Many Faces of Moeritherium
- National Geographic News: Hobbit-Like Human Ancestor Found in Asia
- University of California Museum of Paleontology: The Stegodontidae
- University of California Museum of Paleontology: The Gomphoptheriidae
- Illinois State Museum: The Midwestern United States 16,000 Years Ago: The Late Pleistocene Extinctions
- San Diego Natural History Museum: Fossil Field Guide: American Mastodon