Baby Mammoth CT Scan Reveals Internal Organs

James Owen
for National Geographic News

April 11, 2008

The frozen body of a baby woolly mammoth discovered last year in Arctic Russia has provided the first detailed internal look at a prehistoric mammal, scientists report. (See photos.)

The remarkably preserved mammoth calf is named Lyuba after the wife of the hunter who found the 37,000-year-old carcass in the remote Yamalo-Nenetsk region in May 2007.

The oxygen-deprived environment of its final resting place, likely a watery marsh or bog, prevented decay and kept it intact save for only its tail and shaggy coat.

Estimated to be just three to four months old when it died, the female has now been returned to Russia from Japan after undergoing computer tomography (CT) scans.

The Jikei University School of Medicine in Tokyo produced 3-D images of Lyuba's innards, including her heart, liver, and other organs.

"Now we can see all the internal organs in their natural position inside the body," said study team member Alexei Tikhonov, deputy director of the Russian Academy of Science's Zoological Institute in St. Petersburg.

"We received very, very good results," he said, adding that Lyuba represents the best-preserved mammoth specimen so far found.

"This is really the first case where we can see the internal structure of an extinct animal."

Watery Death

The CT scans showed healthy fat tissues and no signs of damage to the skeleton, indicating the 110-pound (50-kilogram) calf was in good shape when it died, Tikhonov said.

It's thought the Ice Age mammal met its end suddenly, when it drowned in a river or a lake, as its trunk, mouth, and digestive tract contained large amounts of mud.

"The last movements of the trunk and its last breathing was bringing a lot of silt inside," Tikhonov said.

The mammoth calf probably had milk for its last meal, because, like elephant offspring, it wouldn't have been able to digest any other food until it was at least a year old.

The new findings represent only the preliminary results of the CT scans, Tikhonov pointed out.

A team lead by Naoki Suzuki of the Jikei University School of Medicine is still working to complete 3-D images of Lyuba's entire body as well as individual body parts such the organs and muscles.

The team hopes those images will be ready by the end of May.

The next stage of the study will involve analysis of tissue and bone samples based at the Zoological Museum in St. Petersburg.

These biopsies should provide researchers a wealth of information, Tikhonov said.

As well as giving insights into the structure of mammoth organs, glands, and muscles, "prehistoric viruses may be preserved within these tissues," he said.

"We now have probably the first chance to take fragments of DNA from ancient viruses from inside [an animal]," Tikhonov added.

Scientists are also keen to study the contents of the mammoth's intestines, "because inside there will be the pollen and spores of plants, and so then we can reconstruct the landscapes of this time," Tikhonov said.

Cloned to Life?

In addition, labs in the United States, Canada, and Russia are set to work on DNA samples from the fossil in a bid to decode the complete genome of mammoths.

Techniques developed during this genetic research could one day help in bringing extinct species back from the dead, Tikhonov suggests.

He sees no point in attempting to revive the woolly mammoth, because the type of environment and climate it needs no longer exist. But other disappeared animals could be accommodated, he said. (Related: "Mammoths to Return? DNA Advances Spur Resurrection Debate" [June 25, 2007].)

Possible candidates include the Stellers sea cow, a manatee-like sea mammal from the North Pacific that was hunted to extinction in the 1760s, and giant flightless birds such as New Zealand's moa, which also fell victim to humans, he said.

Lyuba's long-term legacy, Tikhonov said, could help "mankind to pay his debt to the extinct animals of historical times."