“Extreme Mammals,” a travelling exhibit of artifacts from the American Museum of Natural History demonstrating the remarkable diversity in the mammal kingdom, opens Saturday, March 2, at Fernbank Museum of Natural History. The museum is open Monday-Saturday, 10-5; Sunday, noon-5. Tickets: $17.50 adults, $16.50 seniors and students; $15.50 children 3-12; members free and children 2 and under free; 767 Clifton Road NE, Atlanta, 30307; information: 404-929-6300, fernbankmuseum.org/.

Alexi Chisler, an exhibition coordinator with the American Museum of Natural History, gets into her work.

On a mid-February morning, Chisler, 35, had climbed all the way inside her latest project, bathed in a dim ochre light, perched in the cave-like interior of a prehistoric creature that ate leaves and shrubs 30 million years ago.

Briefly swallowed by a model of the Indricotherium, the largest mammal that ever walked the earth, Chisler was helping assemble the dramatic monster in a downstairs gallery of the Fernbank Museum of Natural History.

“It takes two people, one inside and one outside, to bolt the panels on,” said Chisler. “They are actually rather light.”

Though life-size, the model is constructed of lightweight (and translucent) fiberglass panels, hung on a wood-and-steel armature, but at 15 feet tall and 21 feet long, the real McCoy was a hefty vegetarian, weighing in at 20 to 30 tons.

Meticulously constructed — each eyelash was fletched by hand — the model is also a dramatic sight. It soars nearly to the ceiling of the first gallery to house a new show called “Extreme Mammals,” a collection of models, fossils and stuffed specimens on loan from the American Museum of Natural History.

Fernbank’s exhibit tells the mind-boggling story of the birth and evolution of this class of warm-blooded animals and the bewildering diversity within it, from the 21-foot Indricotherium, a rhino-like creature, to the 1 1/2-inch Batodonoides, an extinct relative of the shrew and the smallest mammal known.

(The diminutive prehistoric shrew was discovered when a scientist, examining fossil remains under a microscope, realized that he was probably looking at tiny, tiny teeth.)

There are some significant fossils and casts of fossils in the collection. One of these is a copy of Ida, a 47 million-year-old lemur-like anthropoid discovered in Germany that is the earliest known animal with an opposable thumb and perhaps is the missing link between humans and more primitive primates.

Soft tissue and hair were preserved in this raccoon-sized specimen, which gives a startling impression to the visitor that you’re looking at the skeleton of a deeply ancient monkey.

Some of the highlights of the exhibit include:

  • The jaw of a Platybelodon or shoveltusker, an elephant-like creature with a lower teeth and jaw so ridiculously elongated it looks like a joke, or a mammalian version of the C-5 cargo plane.
  • A snouted furry animal called Macrauchenia, first discovered by Charles Darwin on his voyage to Argentina. Comparing the ancient fossil to modern elephant skulls, scientists determined that the animal probably had an elephant-like trunk. The red fur and rubbery snout of the model look vaguely familiar to fans of a certain television creature. "We call him Alf," said one museum worker.
  • The Uintatherium, the first giant mammal fossil ever discovered, an almost-complete skeleton that, though it's only about seven feet long, was so heavy that it was bolted to the concrete floor of the New York museum. Lynn Anders, manager of animal programs at Fernbank, said the curators in New York sawed out a section of the floor to allow the fossil to be transported with the exhibit, rather than unbolt the specimen.

“It comes with its own wheels,” she said.

  • A dramatic tableau from the La Brea tar pits in Los Angeles, showing the actual fossilized skeleton of a Glossotherium, or giant ground sloth, being attacked by the fossilized skeleton of a Smilodon fatalis, or saber-toothed cat. Anders said the profusion of predator fossils in the tar pits led paleontologists to surmise that saber-toothed cats would attack prey that had become stuck in the tar, and then the predators themselves would become stuck.

Some 13 tractor-trailers were required to ship these artifacts to Fernbank, in more than 100 custom-designed, climate-controlled cases. They come from a collection that defies the imagination. “Billions,” said Rachel R. May, of the New York museum, describing how many items the museum has in its various collections.

The collection is huge because the museum continues to send researchers around the globe, searching out the health of species and occasionally discovering new ones.

That, in fact, is how the striped rabbit was identified, in the Annamite Mountains near the Laos/Vietnam border. One of the most recently discovered mammals in the exhibit, it also came into the collection in an unusual way: It was purchased at a food stall at an outdoor market, where it was ready to become someone’s dinner.