An underwater cave in Madagascar has revealed hundreds of fossils of an extinct lemur, possibly washed in case of storms underground for thousands of years.
The Lemur cemetery also contained fossils of a group of extinct animals, including primates, hippos, crocodiles and the largest cat on the island. The landslide, where the bones were found to be retained by a few thousand years, the fossils, said Alfred Rosenberger, an anthropologist at Brooklyn College, City University of New York, who led the team.
"It's a reasonable condition understatement," said Rosenberger Live Science. "The skull and jaws are practically complete and very often even without damage. So let's bring 12 skulls of some kind, and they are absolutely perfect."
It is not clear how they got the animals in the watery grave, but one possibility is that animals during hurricane season or a flash flood swept under water, Rosenberger said.
Trenches
Subsidence can often unprecedented look into the past, because the water still cold protects the bones from the ravages of bacteria, wind and waves, Rosenberger said. He and a team of divers underwater cave were exploring caves in the Dominican Republic when the lead diver, Phillip Lehman, has advice on a sink in the Tsimanampetsotsa National Park, an arid region with seasonal storms in Madagascar, whose limestone rocks have been removed ate water and wind over time, so that a landscape of caves and tunnels similar to Swiss cheese.
To see what was inside, a group of divers traveled 82 feet (25 meters) below the water surface in a vertical well, called Aven (the "sink" means in French). In the transition zone, where to express the watercourses in low light the dark, the team found hundreds of animal bones of dozens of species.
Since cave diving is very dangerous and requires strict safety protocols, and divers can only be under water for a few hours, the team was not able to ignore completely the fossils. But what they found was stunning.
Menagerie of creatures
Many of the fossils belonged to an extinct lemur researchers as pachylemur insignis tentatively identified. Four fossils belonged big cats such as the massive, extinct cat Cryptoprocta spelea. The oldest fossils of cave animals that died a few thousands of years, while others came from a rodent still alive who was introduced to the island by humans, came Rosenberger said.
It remains a mystery how the animals stop there. Unlike other caves, animals, except maybe the crocodile, probably unknown in the sump, Rosenberger said.
"To not live underground, they do not underground shelter. It is highly unlikely that the enormous accumulation of bones could have been because the animals did not stumble" lemurs, Rosenberger said.
Instead, it is possible that a number of events, such as floods or hurricanes that swept the animals over time, said Rosenberger. The presence of stalagmites formed from the drip drip steady trickle of mineral-rich water from the roof to the floor of the cave, the cave suggests once was dry, and would have no land on which water could land, Rosenberger said, By data the thorium and uranium isotopes, or elements with different numbers of neutrons, the researchers were able to determine when there was a lot of flooding, the researchers reported in the article, which was published in the edition of April issue of the Journal of Human Evolution,
Rapid extinction
Since many of the fossils found in the researchers may soon be able to get the fossils come to help them determine if some of these historic creatures became extinct
This could also light on one of the most pressing problems of the island.
"We are the animals of Madagascar at an enormous rate lost to extinction," Rosenberger said.
Humans first colonized the island around 3,000 years ago, and if some of these fossils were deposited overlap, so the cave could help determine if the man played a major role in the extinction crisis of the islands, Rosenberger said.
0 komentar:
Posting Komentar