New fossils threaten an extinction theory
Recent discoveries of long-gone marine invertebrates call into question the occurrence of a catastrophic global extinction hundreds of millions of years ago. The loss of diversity wasn't as widespread and didn't last as long as paleontologists had previously thought, several researchers now suggest.
The extinction during the Late Devonian period is widely considered one of the five massive extinctions in Earth's prehistory. The die-off climaxed at the end of the period's Frasnian stage, which lasted from around 385 million to 375 million years ago. The extinction began an extended interval of low biodiversity known as the Famennian stage. Coral reef ecosystems collapsed at the Frasnian-Famennian transition, and their gradual recovery took about 20 million years, until the end of the Devonian, many researchers say.
New data, however, suggest that at least some marine organisms rebounded quickly during the Famennian. Johnny A. Waters of the State University of West Georgi
