Barren Siberia, Of All Places, May Be Original Home To Animal LifeUF's Joe Meert and KU's Bruce Lieberman concluded that precursors to modern continents began splitting off from a giant supercontinent at the South Pole about 580 million years ago, migrating north toward the equator for about 80 million years. The scientists' analysis suggests that a prominent theory holding that the continents moved far more rapidly is wrong. It also suggests that trilobites, the long-ago forbearers of crabs and lobsters, originated in present-day Siberia when it was a separate continent from Asia and located much farther south... Working independently, the UF and KU geologists each determined that the southern supercontinent began breaking up around 580 million years ago. The separate continents drifted northward toward the equator at about six inches per year, with this relatively rapid movement ending about 500 million years ago, they found... While six inches is fast by comparison to today's continental movement of speed of one to two inches per year, it is far slower than that proposed by another prominent theory on early continental movement. That theory, known to scientists as "inertial interchange true polar wander," held the continents rotated from the South Pole to the equator in a mere 15 million years from 523 million to 505 million years ago - meaning they moved at more than 25 inches per year - more than four times faster than what Lieberman and Meert found.
Science News
adapted from materials by Univ of Florida
Thursday, April 8, 2004
This appears to be an error, although the exact placement of the Trilobites within the Arthropod id not certain. It appears that trilobites are no closer to crustaceans than they are to spiders and insects. Trilobites were an independent subclass of Arthropoda, and are totally extinct.