Wednesday, September 7, 2016

Really old climate records

The Burgess Shale
Watercolour and crayon
©2016 Charlene Brown

The Burgess Shale was discovered by paleontologist Charles Walcott in 1909 high on a ridge above Emerald Lake in Yoho Naitonal Park.  He was so impressed with the extent and diversity of the layers of fossils, that he returned over a dozen times, finding more life forms every time. Over the years since Walcott’s discovery, the Geologic Survey of Canada and the Royal Ontario Museum got involved and many additional outcrops have been found, stratigraphically both higher and lower than the original. These localities continue to yield new organisms faster than they can be studied.

The Shale has attracted the interest of paleoclimatologists who are studying fossil records that appear to show a rapid acceleration in the diversification of complex organisms during the Cambrian Explosion.  This evolutionary event was a short period half a billion years ago, during which most major phyla in existence today appeared.  When researchers understand the climate of that period and its effects, they may be able to predict long-term future effects of climate change on species diversification and extinction.