[Paleopsych] NYT: Old, for Sure, but Human?

[Premise Checker]

Old, for Sure, but Human?
http://www.nytimes.com/2005/12/13/science/13find.html

[This could prove to be a major, major anomaly.]

    Findings
    By JOHN NOBLE WILFORD

    What is one to make of the intriguing footprints found in Mexico?

    The scientists who discovered them said last summer that they were
    made by humans walking in fresh volcanic ash 40,000 years ago. This
    seemed incredible, since no human presence in the Americas had been
    established earlier than about 13,000 years ago.

    So geologists went to the scene, near Puebla. They came to an even
    more astonishing conclusion: the prints were in 1.3-million-year-old
    rock, meaning the prints were laid down more than a million years
    before modern Homo sapiens evolved in Africa.

    The surprising antiquity of the rock bearing the prints was determined
    by a research team led by Paul R. Renne, director of the Berkeley
    Geochronology Center in California. The researchers conducted repeated
    argon dating and investigated the magnetic imprint in the rock. All
    the tests yielded the 1.3-million-year date.

    In the journal Nature, the team wrote, "We conclude that either
    hominid migration into the Americas occurred very much earlier than
    previously believed, or that the features in question were not made by
    humans on recently erupted ash."

    The original discovery was made in 2003 by Silvia Gonzalez of
    Liverpool John Moores University in England. Dr. Renne questioned that
    these were, in fact, footprints. "Their distribution is quite random,
    not like something made by early humans," he said by telephone.
    Paleontologists she consulted, Dr. Renne said, agreed. It may be, they
    said, that the prints are recent breaks in the hard surface caused by
    vibrations from a nearby highway and an active quarry.