When we were in Field, B.C. this summer, I first heard about the Burgess Shale fossils in Yoho National Park. The Burgess Shale quarries have been designated a World Heritage Site by UNESCO. Indeed, the entire park is part of a World Heritage Site. Because of the force of the land’s beauty, I bought a small book, A Geoscience Guide to The Burgess Shale by Murray Coppold and Wayne Powell to begin learning about the fossils. I’m using that book and How Old is That Mountain? by Chris Yorath as references in this post.
The name Burgess Shale refers to a segment of layered rocks, called a formation. It’s within this particular formation that the fossils of well preserved soft bodied creatures were found. This is a big deal because it’s much more common to find only the skeletons of animals without their soft tissues being preserved.
The Burgess Shale fossils were first found in 1909 on a ridge between Wapta Mountain and Mt. Field. And on nearby Mt. Stephen, many trilobite fossils have been found. I’ve compared my photos of mountains in the area to several online photos. From this comparison, I’ve included two photos I took that I believe show the area close to the the Burgess Shale fossil quarries as well as Mt. Stephen.
While I gather that there’s no one exact indication of the age of the fossils, the two books I’ve mentioned indicate they are between 530 and 505 million years old. In A Geoscience Guide to The Burgess Shale the authors compress the earth’s history into a single year to help us fathom the enormous sweep of time of the planet’s history. If the birth of the earth is imagined to be on January 1, then the animals of the Burgess Shale appear on November 20th. As a comparison, dinosaurs who seem incredibly old to us are more recent than the fossils, appearing between December 21st and 27th. And humanity’s ancestors appear at 9:07 p.m. on December 31st. Homo sapiens, our exact species, only appear on December 31st at a quarter to midnight! We are the newcomers on earth.
Because of my new interest, I indulged in the common tourist activity of buying a t-shirt memento of this part of our travels. The shirt has a rendition of some of the amazing looking fossilized creatures of the Burgess Shale. I look forward to wearing it around Toronto next spring and summer. I will certainly receive puzzled looks from people who are not paleontology buffs, wondering what on earth it’s about. What on earth, indeed!