Oldest Primate Fossil Found

New Scientist has a story on the discovery of what may be the oldest definable primate, called Archicebus achilles.  Nicknamed "Archie" (naturally), the fossil dates from the Palaeocene, around 55 million years ago.  Michael Marshall, of the New Scientist writes:

According to its discoverers, Archie is a primitive tarsier – a group of primates closely related to monkeys, apes and humans. That would mean it is descended from the ancestor of all primates, but is not itself the ancestor.

That may not be the end of the story, though. Marc Godinot of the National Museum of Natural History in Paris, France, is not entirely convinced that Archie's snout is short enough to prove it is a tarsier, as its discoverers claim. "Here we have a primate which is so primitive that it could be the primitive primate," says Godinot.

In the new, genetically informed taxonomy, the two main primate branches are prosimians on one branch, which include tarsiformes and lemuriformes and anthropoids on the other branch. The lemuriformes are further subdivided into the lemurs and lorises. The anthropoids divide into New World primates, which become New World monkeys and Old World primates, which divide into monkeys, apes and humans.So, is this a direct ancestor of our line?  Maybe, maybe not.