The teeth of a tiny primate, which probably weighed but a single ounce and could easily fit in the palm of your hand, was recently discovered on the Gulf Coast Plain of Mississippi and appears to be the earliest primate discovered in North America, dating from 55 mya. The creature, named
Teilhardina magnoliana, was a very primitive relative of the wide-eyed, tree-dwelling tarsiers, primates which still live in southeast Asia today. This discovery suggests that
Teilhardina migrated to North America across the Bering land bridge from Asia and raises the possibility that primates had appeared in North America before their close relatives showed up in Europe – a position that contradicts earlier studies.
Teilhardina fossil remains have been unearthed in Asia, Europe and North America dating from this time and led to speculation about how they spread. Previous research suggested that North America was the last place they migrated to, having come from a western direction through Europe, based on the fact that
Teilhardina fossils found in Wyoming’s Big Horn Basin appear to be considerably less primitive than those discovered in either China and Belgium. The new discovery in Mississippi reverses the direction of this global migration since the teeth seem to have fewer modern features than those found elsewhere.
The discoverer of the fossils, Christopher Beard, a paleontologist at the Carnegie Museum of Natural History claims that not only are the Mississippi
Teilhardina fossils more anatomically primitive than the ones so far found in Europe, but they are also found in slightly earlier deposits. It looks like they were uncovered in sediment that is below the line that marks a drastic drop in worldwide sea levels whereas the Belgian fossils were discovered slightly above this line. Hence, the sea level was still falling when the Mississippian
Teilhardina fossils were deposited and had already fallen by the time the European
Teilhardina fossils were deposited.
But the discovery and the conclusions are still controversial because the ages haven’t been verified due to a lack of a clearly appropriate carbon isotope signature, and this is sort of considered the gold standard for dating fossils from this time. Approximately 55.8 mya there was a large release of carbon from what had previously been frozen undersea methane deposits that is described as being poor in one specific isotope that has been used as a marker to date fossils from this time. Unfortunately, the Mississippi site shows no clear line from this event, which makes dating the teeth this way nearly impossible. The lack of this carbon isotope data means that the migratory paths used by
Teilhardina are still not known with any certainty. But as Beard notes, either route is impressive for such a tiny animal to have taken.
Further reading can be found here:
Oldest Primate Fossil in North America Discovered
http://news.nationalgeographic.com/n...n-primate.html
How primates crossed continents
http://www.nature.com/news/2008/0803....2008.637.html
Scientists Unearth Fossils of 1-Ounce Primate in Mississippi
http://blog.wired.com/wiredscience/2...ists-unea.html
One-Ounce Mississippian of 55.8 Million Years Ago
http://www.nytimes.com/2008/03/04/sc...ml?ref=science
Pint-sized primates were first in North America
www.msnbc.msn.com/id/23455662/
A long trek for ancient mini monkeys
http://www.boston.com/news/science/a...cient_mini_mon
keys/
Carnegie Museum's monkey fossils ignite controversy
http://www.pittsburghlive.com/x/pitt.../s_555337.html