A storied trove of fossils from a Canadian paleontological site is yielding new clues to an explosion of life on earth
By Siobhan Roberts
Smithsonian magazine, July 2009
The fossil-hunting expedition began with a lung-busting hike, accompanied by an incessant ring-ding-ting-clank-clank-ring-ting-ding-clank. The soundtrack came courtesy of an anti-bear bell attached to the backpack of the group's leader, Jean-Bernard Caron, a curator of invertebrate paleontology at Toronto's Royal Ontario Museum. After four hours of hiking up switchbacks through an evergreen forest deep in the Canadian Rockies, Caron suddenly took off like a mountain goat. As the others caught their breath, he zipped his way across loose and jagged rock up the final ascent. Eventually the team reunited at the top of the cliff and collapsed, surveying the view over the Burgess Shale.
The rich fossil repository known as the Burgess Shale was first discovered a century ago.
"Yay! Fossils! We're really here!" exclaimed Allison Daley, a graduate student from Sweden's Uppsala University. She bit into an Oreo cookie and fanned her face in nervous excitement.
The Burgess Shale is Mecca for paleontologists. Charles Doolittle Walcott, the fourth Secretary of the Smithsonian Institution, discovered this rich fossil bed a century ago, in the summer of 1909, and named it for nearby Mount Burgess. At the end of his first field season here, Walcott wrote in a letter to a colleague that he had "found some very interesting things." Talk about understatement. The Burgess fossils tell nothing less than the story of the Cambrian explosion—evolution's Big Bang—when relatively simple organisms rapidly diversified into the sorts of animals that live today. The exquisitely preserved Burgess specimens (most likely entombed by underwater mudslides) include the remnants of soft-bodied organisms, which are rare in the fossil record. The animals inhabited the ocean floor 505 million years ago, near the end of the Cambrian Period.
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