Thousands of years have passed since the last mastodon nibbled on the alder in Alaska. But one is standing at the Anchorage Museum right now. Or rather, its bones are.

The immense skeleton is actually a replica, but there are plenty of real bones, teeth, hair and other parts of Alaska’s pachyderm past in the exhibit, “Mammoths and Mastodons: Titans of the Ice Age,” on display here through fall. Actual bits of mammoths — the official Alaska state fossil — include a tusk from one beast that rambled around St. Paul Island a mere 5,700 years ago.

There are also full-size replicas of several ice age giants, some nearly reaching the ceiling of the museum’s third floor: a Columbian mammoth, larger than its woolly cousins; a short-faced cave bear; a homotherium — popularly known as “saber-tooth tiger.”

“These are very dramatic animals,” said Daniel Fisher of the University of Michigan Museum of Paleontology. “You’ll be thankful they don’t survive in parts of Alaska today.”

But when you see the life-size model of little Lyuba, the 45-inch long baby mammoth found preserved in Siberia, it’s easy to wish that at least some of the Pleistocene’s proboscideans had made it to today.

Lyuba suffocated in mud an estimated 40,000 years ago. Her excellently preserved soft tissues and material in her digestive tract supplied scientists with a trove of information. Her fortuitous preservation came about as a result of being infested with acid-producing bacteria that in effect pickled her as she froze in the permafrost.

Fisher is the guy who figured that out. Among the world’s most prominent mammal paleontologists, he is the show’s guest curator, a position somewhat analogous to being the director of a movie. He helped design and implement the exhibit, which originated with Chicago’s Field Museum, finding specimens for display, corralling the latest research.

Various types of proboscideans — mammals with trunks and tusks — once flourished in every continent except Australia and Antarctica. They sported different teeth, different tusk configurations, different diets and probably very different lifestyles. Mammoths were grazers, like sheep or cattle, Fisher said. Mastodons were browsers, living on leaves and branches, like moose or giraffes.

Mastodon fossils have been found as far south as northern Mexico. Mammoths lived all the way into modern Costa Rica. Other proboscideans migrated into South America.

Then they died out. The most recent remains, those of a dwarf species, were found on Wrangel Island, 500 miles due west of Barrow. The last of the race would have been on Earth at about the same time as Moses was arguing with Pharaoh.

The exhibit employs fascinating video that makes it easy to understand things like how these giants differed from one another, how scientists sleuth out their lives and their world, what kind of environment they thrived in.

For instance, a common image of the ice age is of a world covered by glaciers. But, though it was colder than now, the age of mammoths also had ample fields, brush, forests and other forage. It had to; a big mammoth required 500 pounds of food a day.

The hairy giants were the biggest animal on the ancient Alaska landscape, sharing the terrain with a variety of other animals that are no longer here: steppe bison, horses, lions.

“They lived in small to medium-size family groups,” said Fisher, “sometimes aggregating into herds. And they moved, possibly seasonally or over longer times, conceivably hundreds of kilometers looking for grasses and sedges.”

Scientists know a lot about mammoths and mastodons because they only recently became extinct, relatively speaking, and fossils are abundant.

“There’s an excellent record of mammoths in Alaska,” Fisher said, in part thanks to the gold mining industry. “People working gold fields had to move the Pleistocene muck to get to the gold. They used hydraulic equipment to melt and remove the overlying deposits to gain access to the gravels. In so doing they exposed everything that was there: trees, plants, and lots of bones of animals that lived and died on that landscape.”

Many of the fossils on display in fact come from Alaska; some are on loan to the Field Museum from the University of Alaska Museum of the North in Fairbanks, including a beautiful skull showing the woolly mammoth’s high cranium — a feature that suggests (perhaps anthropomorphically) intelligence.

It would be one of many similarities they share with their hairless living relatives. A fact sheet from the museum notes that mammoths and modern elephants share 99.4 percent of the same genes.

“Mastodons are a separate lineage,” said Fisher. “They split off 30 million years ago and are not so closely related. But mammoths and elephants are very close. Their common ancestor is around 7 million years ago and we think they were also similar behaviorally.”

How did such successful creatures become extinct? Theories about disease or an extra-terrestrial impact have not stood up to investigation, Fisher said. But he was cautious in balancing the claims of researchers who think it was due to climate change and those who point to human hunters.

Both of those theories have grounds for credibility. Around 11,000 years ago, global warming swept the earth. Glaciers melted. Sea levels rose. Vegetation changed. Nomadic people began to congregate in permanent communities. Traders and manufacturers in the cities of Egypt and Mesopotamia began to exploit the breakthrough technologies of iron and writing at about the same time the tusk from St. Paul was attached to a living, breathing mammoth.

One of the most intriguing displays in the exhibit is not the massive animal bones, but art, hand-size carvings created by human beings who saw and rendered the images of the mammoths that were part of their world.

Some bones include spear points and other evidence of hunting. One such find, in fact, started Fisher on his road to becoming Mr. Mammoth. He had worked in other paleontological disciplines, but shortly after he arrived at the University of Michigan, some 30 years ago, a mastodon was discovered nearby. Every scientist in the area joined in the field excavation, including Fisher, though he said he was mainly there as an observer.

Then, a short time later, another was found. “No one else was available,” Fisher said. They were all busy with the first mastodon. “So I went out and I was fascinated by the differences between it and the one I’d just seen.

“In the end I decided the differences had to do with the second one probably having been butchered by humans while the first was a natural death. I got to thinking about the topic and found it very intriguing.”

If ancient humans contributed to the demise of the titans of the ice age, their modern descendents may be able to use what they’ve learned to help save the modern descendents of the mammoths. The final part of the exhibits deals with elephants, whose survival in the wild is seen as under threat at this time. Those who consider the largest land animal to be kind, wise and gentle — as reflected in the tales of Babar, Horton and Dumbo — feel concern for the giants. Worldwide efforts may help protect them from poaching; but protecting their habitat, or even having solid knowledge about how to do so, may be harder.

There’s where the fossil record can assist, said Fisher.

“Some of what we’ve learned about the mammoths could help with conservation of their living relatives,” he said, and gave an example. “Many aspects of the animal’s diet are recorded in their tusks. Knowing that, we can look to modern day elephants tusks and essentially reconstruct details of individual lives without having seen the individual animal.”

The exhibit will remain in Anchorage through Oct. 9. After that the mammoths and mastodons will lumber off to Denver, Boston, London and other cities on a five-year tour.

Author: Mike Dunham | Source: Fairbanks Daily News-Miner [March 20, 2011]