Researchers discover undersea graveyard of extinct giant lemurs

Chuck Bednar for redOrbit.com – @BednarChuck

An undersea graveyard containing hundreds of bones of extinct giant lemurs, some as large as gorillas, has been discovered by a team of divers and paleontologists in Madagascar.

According to National Geographic, the fossilized remains were discovered at the bottom of Aven Cave in the island nation’s Tsimanampetsotse National Park. While the bones of other types of extinct creatures were also found there, the majority of them belonged to the large extinct lemurs known as sloth lemurs, koala lemurs, and monkey lemurs, the website noted.

Those names were given to the different types of lemurs because of their unique lifestyles, as well as to link them with the modern-day animals that they most resembled. These giant lemurs all died out roughly 500 to 2,000 years ago, possible at the hands of humans, they added.

Brooklyn College anthropologist Alfred Rosenberger, a National Geographic grantee who is leading the project, said that the underwater cave is allowing scientists to take an unprecedented look at these unusual creatures. Their remains have been incredibly well preserved, he added, but the question remains: exactly how did these creatures find their way into Aven Cave?

Rosenberger and his colleagues have only started the process of cataloging what they discovered on the surface of the area, and have yet to begin work on determining how this underwater grave came to be. However, based on the information currently available, they believe that most of the bones washed into the cave over a long span, both before and after the arrival of people.

Along with the individual lemur bones, the cave is home to entire skeletons that has helped give researchers a more in-depth look at the anatomy of these extinct creatures. There are few signs of post-death damage, which would indicate that they were killed and eaten by predators, and it appears as though the bones became exposed as the dead lemurs slowly decomposed.

Two of the more exciting discoveries center around newly discovered remains of the extinct lemurs Pachylemur and Mesopropithecus. Pachylemurs were closely related to the modern-day ruffed lemurs, except that they were at least three-times larger, while Mesopropithecus was a small to medium sized creature that was a member of the sloth lemur family.

“We have a real cross-section [of both] tiny things and big things,” Rosenberger told National Geographic. In addition to the lemurs, several other types of animal remains were found in the cave, including birds, turtles, crocodiles, rodents and carnivores – and that’s only what they can currently see on the cave floor. “Who knows what’s under there?” he added.

The research team was led by Phillip Lehman of the Dominican Republic Speleological Society, and has also explored two other caves in Madagascar where they found well-preserved remains of other creatures from the same time period, the website said. One of those, Mitoho Cave, looks as though it was the den of an extinct carnivore known as the giant fossa (Cryptoprocta spelea).

Stony Brook University anthropologist William Jungers said that the newly-discovered skeletons will give paleontologists their best opportunity yet to study lemur species that previously could only be assembled using isolated parts. “I hope the fossils will yield dates and perhaps [ancient] DNA that will bear upon the extinction process that took place,” he added.

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