For decades, scientists have accumulated ever-larger datasets
that suggest an enormous space rock crashed into the ocean off
the Yucatan Peninsula more than 65 million years ago, resulting
in the Cretaceous-Paleogene (K-Pg) extinction. News story
originally written on March 4, 2010 Last year, though, a
research team suggested that the impact could have occurred
300,000 years prior to the K-Pg extinction, and that another
cause--perhaps a second impact, or the long-lasting volcanic
activity at the Deccan Traps in what is now India--drove
numerous plant and animal species to their end. Now, a team of
41 scientists from 12 nations has prepared a paper to
specifically counter the volcanic and dual-impact alternatives,
and provide a comprehensive review of the evidence linking a
single impact near what is now Chicxulub, Mexico, to the K-Pg
extinction. One factor that is not in dispute: the end of the
Cretaceous 65.5 million years ago was marked by one of the most
devastating extinctions ever. The most famous victi