Denver scientist leads discovery of bizarre mammal species

For millions of years, a badger-like creature wandered the forests and plains of prehistoric Madagascar avoiding the predatory glare of giant crocodiles and snakes before perishing in mass extinction along with the dinosaurs.

For millions of years more, nobody knew of the critter’s existence until an international team of researchers led by a Denver paleontologist dug up its bizarre bones. The discovery of the creature, announced Tuesday, is an important clue for scientists researching how animals evolved on islands, said David Krause, senior curator of vertebrate paleontology at the Denver Museum of Nature and Science.

The team named the creature Adalatherium, a combination of the words “crazy beast” in two languages. The skeleton they found is the largest and most complete mammal skeleton ever found from that time period in the southern hemisphere. Other mammalian remains have been only fragments belonging to animals about the size of a mouse.

“Adalatherium is just one piece, but an important piece, in a very large puzzle on early mammalian evolution in the southern hemisphere,” Krause said in a news release from the museum. “Unfortunately, most of the pieces are still missing.”

The creature walked or wobbled — scientists aren’t really sure how it moved — among dinosaurs and likely perished in the same mass extinction event that wiped out many of the creatures of that time. Adalatherium was about 20 inches long, weighed about 7 pounds and looked somewhat similar to a badger, scientists believe.

Krause and his team have traveled regularly to Madagascar since 1993 to search for bones and other clues about life from long ago. The team’s other discoveries on the island are equally bizarre. They found ancient remains of a giant, armored frog that hunted its prey. They’ve found a snub-nosed crocodile with a vegetarian diet and a dinosaur with buck teeth.

“Madagascar is a pretty weird place,” Krause said.

It took years for the international team of scientists to even realize they had found Adalatherium, Krause said. The bones were excavated in 1999 from a grassy knob on Madagascar’s plains because a graduate student found an ancient crocodile skull. It wasn’t until 2002 that Krause found there were also mammal bones in the plaster encasement.

“We rushed to find a portable X-ray unit and lo and behold, we could see that an entire skeleton was beneath the surface of rock matrix,” Krause said.

The team then spent years preparing and studying the skeleton. The painstaking, intensely detailed research documented every notch of the bones. Researchers scanned the bones and then studied them on the computer pixel by pixel.

“The overriding reason for delay is that the skeleton was so bizarre and we just didn’t know what it was,” Krause said.

The skeleton has many unusual irregularities, like a mysterious hole in the top of the snout that “defies explanation” and curved leg bones, Krause said. Scientists hypothesize that the Adalatherium burrowed using its back legs and had rodent-like teeth. They don’t know how it reproduced.

Krause and his team continue to study the creature, though the skeleton is in different parts scattered around the globe for research. Krause has the skull in Denver.

“It’s right now torn apart and roughly 2500 miles apart,” Krause said.

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