Dwarf elephants and shedding mammoths shine at NYC's 'Secret World of Elephants'

A woman and child look at the full-size model of a woolly mammoth with curly tusks at a museum exhibit.
The new exhibit sports a full-scale model of one of the most iconic extinct elephant relatives — a woolly mammoth, depicted in the process of shedding its winter coat. (Image credit: Alvaro Keding/© AMNH)

After the dinosaur-killing asteroid struck Earth about 66 million years ago, it took only a few million years for the earliest known elephant relative to emerge.

This was the dog-size Eritherium, the earliest known proboscidean, which lived around 60 million years ago in North Africa.

"But it didn't look anything like a modern elephant," Ross MacPhee, curator of "The Secret World of Elephants," a new exhibit opening Monday (Nov. 13) at the American Museum of Natural History (AMNH) in New York City, told Live Science. "There were no big tusks and no large body size."

The 10-pound (4.5 kilograms) Eritherium is just one of the species highlighted in the exhibit, and one of more than 200 proboscidean species that have lived on Earth. Today, only three remain: the African savanna elephant (Loxodonta africana), the African forest elephant (Loxodonta cyclotis) and the Asian elephant (Elephas maximus).

"The Secret World of Elephants," has life-size models of an adult and calf pair of dwarf elephants (Palaeoloxodon falconeri). These extinct animals, which lived in what is now Sicily, grew to only about 4 feet tall at their shoulders. (Image credit: Alvaro Keding/© AMNH)

These modern elephants and their proboscidean cousins are the main attraction of the new exhibit. But a few iconic pachyderms steal the show, including a life-size model of a 4-foot-tall (1.2 meters) mama Sicilian dwarf elephant (Palaeoloxodon falconeri) and her very hairy calf, as well as a huge model of a molting woolly mammoth (Mammuthus primigenius).

Related: 'It's really quite remarkable': An interview with elephant expert Ross MacPhee about the giant pachyderms

The exhibition features a life-size model of an African elephant — the largest living land animal. A video projection shows the skeleton of this massive mammal and provides an inside look at how it processes the huge amount of food it eats — about 300 to 500 pounds (136 to 226 kilograms) per day — and elephant gestation, which can last for nearly two years, longer than any other living mammal. (Image credit: Alvaro Keding/© AMNH)

Proboscideans didn't always look like today's species; they reached modern sizes only around 40 million years ago, when the 2-ton (1.8 metric tons) Barytherium — which was outfitted with eight very short tusks, four on top and four below — arose.

And once they were big, some proboscideans shrank. These creatures often swam to, or got stranded on, islands. And due to the island effect — that small animals on islands tend to evolve into giant versions of their mainland relatives, and large animals tend to evolve into dwarf versions of their mainland relatives — they downsized. Over time, "they evolved smaller body size because you need less food, less water — it's easier to walk, so also for your joints, it's better" to be small, said Alexandra van der Geer, a paleontologist at Naturalis Biodiversity Center in the Netherlands who served as a consultant for the exhibit and helped create the Sicilian dwarf elephant models.

The full-scale model of a woolly mammoth — one of the most iconic extinct elephant relatives — is shown here as it sheds its winter coat. The ice age beast was crafted onsite by the museum's exhibition team with input from leading paleomammalogists. (Image credit: Alvaro Keding/© AMNH)

Interestingly, the largest and smallest elephants on record came from the same genus: Palaeoloxodon. The largest elephant, P. antiquus — a 13-foot-tall (4 m), straight-tusked beast from Europe — likely swam to Sicily, where its descendants gave rise to the 98% lighter dwarf, P. falconeri.

Meanwhile, the earliest known mammoth (Mammuthus subplanifrons) evolved around 5 million years ago in South Africa. Woolly mammoths evolved about 800,000 years ago, when spreading into Eurasia and eventually North America. Again, due to the island effect, a "mini-mammoth" emerged on the Channel Islands off California. Thought to arise from a Columbian mammoth (Mammuthus columbi), the pygmy Mammuthus exilis stood about 5.5 feet (1.7 m) tall at the shoulders.

The life-size model of the dwarf elephant calf that once lived on Sicily.  (Image credit: Alvaro Keding/© AMNH)

Many proboscideans went extinct at the end of the last ice age, around 12,000 years ago. The reasons for this mass die-off aren't completely understood, but it's likely that both climate change and human hunters played a role, studies have found.

Today, research continues to reveal the secret world of elephants. For instance, DNA shows that their closest relatives aren't hippos or rhinos, which also have thick, gray skin, but rather manatees, dugongs, and furry, rabbit-size hyraxes.The "Secret World of Elephants" will run for at least a year at the AMNH before traveling the country.

Laura Geggel

Laura is the archaeology and Life's Little Mysteries editor at Live Science. She also reports on general science, including paleontology. Her work has appeared in The New York Times, Scholastic, Popular Science and Spectrum, a site on autism research. She has won multiple awards from the Society of Professional Journalists and the Washington Newspaper Publishers Association for her reporting at a weekly newspaper near Seattle. Laura holds a bachelor's degree in English literature and psychology from Washington University in St. Louis and a master's degree in science writing from NYU.