Monday, March 03, 2008

Oldest Primate Fossil in North America Discovered

Teilhardina magnolianaHe was the Albert Einstein of his time -- aside from the fact that this long-extinct critter weighed about an ounce (28 grams), measured three inches long and munched on bugs and berries.

A U.S. scientist has unearthed the remains of the earliest-known primate to live in North America. In doing so, he figured out the path these ancient representatives of the mammalian group that includes lemurs, monkeys, apes and people must have taken to reach this part of the world.

Based on a group of teeth from a teeny primate unearthed in Mississippi dating to 55.8 million years ago, paleontologist Christopher Beard of the Carnegie Museum of Natural History in Pittsburgh said the species likely scampered over a now-vanished land bridge connecting Siberia to Alaska.
Teilhardina magnolianaThe tiny immigrant was called Teilhardina magnoliana, Beard said in the Proceedings of the National Academy of Sciences.

"For his time, he would have been about the smartest animal around. But that doesn't mean he was thinking deep thoughts," Beard said in a telephone interview.

"Primates have nails on their digits instead of claws. Primates have eyes that face forward and give us stereoscopic vision, instead of having eyes on the side of our heads like a dog or a horse. Primates almost always have relatively larger brains than other mammals," Beard said.

Teilhardina would have fit snugly into the palm of Einstein's hands, but its big thoughts were perhaps more practical than theoretical physics.

This arboreal creature was probably most concerned about its next meal of bugs, berries and fruit and staying away from lizards or birds of prey, Beard said, and one other basic instinct -- "Where are the girls?"

"It's a small, primitive primate. In some ways, it would have looked more like a teeny, tiny monkey than it would have looked like a small lemur," Beard said, noting that it lived more than 10 million years before the first primitive monkeys.

It was not ancestral to New World monkeys, but might have been in the lineage leading to a type of primitive primate known as Tarsiers that still lives in southeast Asia, he said.

Fossils of closely related species of Teilhardina have been found in China, Belgium, France and Wyoming. The new species predates the Wyoming one, Beard said, and came from a time period when a route from Asia was the likely path into North America.

There has been some debate within scientific circles about how the most primitive primates first entered North America, with some feeling they crossed from Siberia and others thinking it was overland from Europe by way of Greenland at a time when the continents were aligned differently.

The fossil teeth were dug up near Meridian, Mississippi, close to the former coastline of the Gulf of Mexico. They are older than any primate fossils from Europe, he said, suggesting that rather than migrating from Europe to North America, this primate might have ventured the other way around.

This primate lived 10 million years after the dinosaurs and so many other species were obliterated by a big hunk of space rock, and mammals were exerting their dominance on land.

The Bering land bridge was the route of many migrations over the eons, including dinosaurs. Many scientists believe the first modern humans entered North America over that very same route sometime between perhaps 30,000 to 12,000 years ago.

The world was in the middle of a drastic warming period at the time that was witness to a dramatic radiation of mammal species. In this ancient ice-free world, Alaska must have been a tropical paradise, Beard said.

Story here.

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