A shrewlike mammal called the common tenrec that lives in the forests of Madagascar can sleep, continuously, for up to nine months. A new study of this furry creature's snoozing habits is shedding light on how ancient mammals survived the comet impact that ended that wiped out Earth's dinosaurs. Here's a look at the tenrec study and findings. [Read full story on the hibernating mammal]

Mammal ancestor

The researchers, Barry Lovegrove, an evolutionary physiologist at the University of KwaZulu-Natal in South Africa, and hisgraduate students Keri Lobban and Danielle Levesque, were interested in the life of what is likely the forerunner of most living mammals. The creature, now dubbed Schrëwdinger, is a virtual mammal developed in a prior study of a furry-tailed creature, considered the first placental mammal (shown here). (Image Credit: courtesy of Carl Buell)


Living fossil

Since this "mammal forerunner" is not real and wouldn't be alive today, the researchers turned to a close stand-in: the common tenrec, one of the largest insect-eating mammals, which resembles Schrëwdinger and its lifestyle. (Photo Credit: Keri Lobban)


Afrotheria group

Tenrecs are members of the Afrotheria group, possibly the first new mammal group to evolve from Shrëwdinger at the beginning of the Age of Mammals, researchers said. Such tenrecs may have arrived in Madagascar some 50 million years ago, according ot Lovegrove. Shown here, a pregnant common tenrec. (Photo Credit: Keri Lobban)


Tracking tenrecs

In their study, over two rainy seasons from 2009 to 2011 in Madagascar, Lobban (shown here) and Levesque implanted 15 common tenrecs with radio transmitters and sensors to monitor the animals' body temperatures. (Photo Credit: Barry Lovegrove)


The implant

An implant with a radio communicator and a sensor that recorded the animal's body temperature that is then wrapped in plastic and wax. (Photo Credit: Keri Lobban)


Boa snack

The forests of Madagascar are teeming with all kinds of life, some of which preys on tenrecs. As such, several tenrecs were killed by feral dogs, boa snakes, other predators and even poaching huans. "The common tenrec is a delicacy in most parts of Madagascar," Lovegrove said. "They are hunted relentlessly with dogs." Shown here, a common tenrec eaten by a boa. (Photo Credit: Keri Lobban)


A hungry boa

Here, the boa snake that swallowed a common tenrec in Madagascar. (Photo Credit: Keri Lobban)

Squeezed out

The swallowed common tenrec was squeezed out of the unharmed boa snake's belly. (Photo Credit: Keri Lobban)


Tenrec surgery

The scientists recovered data from three of the tagged tenrecs, finding the animal could hibernate for at least nine months without waking up. In fact, the scientists had to dig up one sleeping adult male tenrec because the transmitter batteries were dying and they didn't want to lose valuable data, Lovegrove said. Here, a common tenrec that received a surgical implant. (Photo Credit: Keri Lobban)