Sunday, 2 September 2018

BURGESS, WALCOTT & WAVING CAMBRIAN WORMS

High up in the Canadian Rockies in an area known as Burgess Pass is one of the most unlikely, perfect and improbably fossil sites on Earth.
Paleontologists and fossil enthusiasts agree that British Columbia has some of the important fossil localities in the world. We are blessed with beautiful, accessible abundant strata and a committed fossil community.

It is easy to forget sometimes just how lucky we are. One of the most amazing fossil sites in the world is in our backyard. The Burgess Shale, a Middle Cambrian site high up (a mighty 2,286 metres above sea level) in a glacier-carved cliff  in Yoho National Park is one of those amazing sites.

The fine-grained shales that make up the Burgess were once part of the ancient landmass known as Laurentia, the ancient geologic core of the North American continent, and are home to some of the most diverse and well-preserved fossils in the world. The sedimentary shales here contain fossils that open a window to marine life some 508 million years ago.

The site is made up of a few quarries and includes the Stephen Formation (Mount Wapta and Mount Field) and the upper Walcott quarry with it’s Phyllopod Bed. There is also a lower quarry named for Professor Piercy Raymond who opened the site in 1924.

It is one of the rare locations in the world where both soft tissues and hard body parts have been fossilized amidst the layers of black shale that form Fossil Ridge and the surrounding areas.
Discovered 109-years ago in 1909 by Charles D. Walcott, the site has continues to wow scientists and the community at large year after year. Charles was in Canada after losing is first wife to a train crash in Connecticut. He met Mary Morris Vaux, an amateur naturalist from a wealthy family and this new love and her interest in the wilds of Canada had brought him back.

Walcott was a geologist, paleontologist and administrator of the Smithsonian Institution in Washington, DC, USA. He was an expert in Cambrian fossils for his time. A company man, he joined the US Geological Survey in 1879 and rose to become a director in 1894.  He served as President of the American Association for the Advancement of Science in 1923 and was an advisor to President Theodore Roosevelt.

Picture the world at this time. Coca-Cola sold their first soft drink, in Germany, Wilhelm Roentgen developed the first x-ray and it was a year before the United States Supreme Court ruled that "separate but equal" public facilities for whites and blacks ought to be legal.

So, up and coming Walcott was up exploring in the Rockies and stopped to rest his horse. Always a rock man, he had his hammer handy and split some likely blocks. They contained trilobites and other arthropods now famous from the site.

While he recognized the significance of the site, it wasn’t until 1960 through the work of Alberot Simonella that the Burgess received the interest it deserved. Charles had a lot on his plate and Simonella picked up the slack nicely.

In 1967, Harry Whittington initiated the Cambridge Project to open up the files and build on the work of his predecessors. He brought two grad students on board (keen but a dime a dozen!) to do the heavy lifting as a means to publish or perish. Both Simon Conway Morris (Worms) and Derek Briggs (Arthropods) completed the trio and the foundation for some serious study finally got underway.
Imagine being Walcott -- his wonder at holding the predecessors of all life in his hands. Seeing the detail. Wondering at the strange and unlikely creatures made real before his eyes. It’s mind-blowing. It is a rare thing to see soft-bodied organisms fossilized. We see this kind of exquisite preservation in the limestones of Solnhofen, Germany, but globally, the occurrence is rare.

Technology has amped up the wow factor and increased our ability to view this ancient past through the use of advanced imaging. Things we’ve only dreamt of are now real. We’ve been able to see nervous systems and discrete organs through this lens.

Every year, a new species or magnificent specimen is unearthed. In 2011, a hiker discovered a rare fossil of Ovatiovemis, a genus of filter-feeding lobopodians. Picture a marine worm with nine arms waving to you. Yep, that’s him. The specimen she found is now described as Ovatiovermis cribratus and is one of only two known specimens of Oviatiovermis from the Burgess.

This important site in the Canadian Rockies has been awarded protection as a UNESCO World Heritage Site (1981) in recognition of the exceptional fossil preservation and diversity of the species found here.

The Burgess Shale contains the best record we have of Cambrian animal fossils. It reveals the most complete record of creatures we have who proliferated the Earth after the Cambrian explosion 545 to 525 million years ago. It was a time of oceanic life. The land was all but inhospitable, barren and uninhabited. Great soft fine-grained mudslides slid onto an ecosystem in a deep-water basin. Millions of years later, this unlikely event was revealed through the fossils preserved in the Burgess. Burgess is unmatched but a fossil find in Kootenay National Park, about 42 kms to the south, gives it a strong run for it’s money. More on that in another post.

Photo Credit: Keith Schengili-Roberts
CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1585076