Scientists combing the Rockies this summer for more evidence of 505-million-year-old fossils nearly missed their eureka moment.
Jean-Bernard Caron, curator of invertebrate paleontology at the Royal Ontario Museum (ROM), said he and his team had checked out an interesting-looking outcrop during a seven-week expedition but, finding no fossils related to the famed Burgess Shale deposits, they moved on.
“We looked at the outcrop and said ‘that looks weird,’ but at the time we didn’t find anything on the slope. It was the end of the day and we were hungry and a long way from where we were (camped) so we decided to move on,” he said.
But as they prepared to move their camp to another location, a niggling feeling they missed something drew them back to the outcrop for a second look.
That second look led the researchers to discover a bed of remarkably preserved fossils that promises to be on par with the famed Walcott Quarry. In 1909, Charles Doolittle Walcott discovered Cambrian Period fossils near Wapta Mountain in Yoho National Park that threw a spotlight on some of Earth’s earliest animals.
“It was a close call,” Caron said. “The first time we went there we didn’t see anything. We didn’t look at the right place initially.”
The team ended up spending 15 days at the new site and while that is a blip in time compared to the 100-plus years the Walcott Quarry has been explored, every day offered a new surprise.
“It’s a very short time compared to the years of collecting that has been done at the Walcott and every single day we found new fossils that we didn’t find the days before. When I say new fossils, I mean new species,” he said, adding this new site has the potential of providing a high diversity of Cambrian-period animals.
The ROM-led expedition set out in July to follow a feature known as the Cathedral Escarpment where Burgess Shale-type fossils are found in the Rockies. They investigated previously known sites, but with the hope of finding new sites and new creatures as well. But to find a site like the one discovered was not expected.
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“We are excited because I think it is perhaps the most important discovery that we’ve made in the last 30 years in the area of Kootenay and Yoho and that is since the finding of about a dozen new sites in the early 1990s by the ROM,” Caron said.
“I’m thrilled and it is an amazing feeling to be able to discover something like this. Even with the amount of time people have spent prospecting in the past in the Rockies, still today you can find these things and I’m sure there will be other sites like this in the Rockies to be discovered in the future if we continue exploration.
“The site itself is as significant as some of the best known fossil localities and comparing this to Walcott is appropriate at this time.”
Caron was reluctant to say much more about the new site, including its location, as both Parks Canada and the ROM need time to begin to understand the site and establish what needs to be done to protect it.
For Parks Canada, which has a mandate to protect and interpret the fossilized creatures of the Burgess Shale, the new site points to the importance of continuing exploration and research, according to Todd Keith, acting manager of integrated land use planning for the Lake Louise/Kootenay/Yoho Field Unit.
“What it does is demonstrate the potential for further knowledge and further research that can shed light on the early evolution of life during that early Cambrian Period,” Keith said.
“We’re definitely interested in supporting scientific research that is needed to shed light on the importance of these fossils and this particular formation, the Burgess Shale formation.”
Keith said one of the ways Parks is managing the Burgess Shale sites is through peer-reviewed scientific research.
“We recognize the value of that in terms of furthering our understanding of what the Burgess Shale tells us about the evolution of life on Earth.”
The first step, at least from the ROM’s perspective, is to name the site and introduce it through publication of a general description of the site, including its geology, fossil content and species composition. Caron said he hopes to have that step completed in the next six months.
Preparation of specimens gathered at the site and detailed research projects will follow that to identify new species and study trace fossils, such as tracks, to learn more about the behaviour of the animals and how they interacted with one another. As well, the site will see research done on the geology and stratigraphy of the site to understand the conditions of preservation.
“In order to grasp the real life diversity at the time, we have to spend more time there, meaning more excavations. We only did small limited excavation this summer; just to be able to see where the fossils came from the stratigraphy,” he said.
Caron described the preservation of the fossils as exceptional and some of the species they found are in better shape than some of the same fossilized creatures found at the Walcott Quarry
“This is really a site that people will recognize in situ as a very important site for various reasons, including diversity of organisms, but also preservation. It is one of the best preservation of Burgess Shale sites I have seen anywhere in the world.”
Creatures that are rare in the Walcott Quarry appear to be common in the new site, which Caron said should allow Burgess Shale researchers to better understand what were once thought of as rare species.
With the volume of fossils, both previously known and new species and the excellent state of preservation, as well as the distance from the Walcott Quarry, this newest find will allow researchers to push their understanding of the Cambrian Period and of evolution of life that much further.
“That combination makes this site very exciting, because it will not only provide information on the evolution of groups of animals that we knew only partially, but also we get information about the ecology and distribution of these species.
“Because the new site is far from the Walcott Quarry that gives us information about distribution of species from the Cambrian Period,” he said.
Even though Caron is already planning a multi-year excavation, he said the new site won’t override other known sites or collections of fossils already held at institutions, such as the ROM and the Smithsonian.
But the simple act of discovering it, with all that it offers, tells Caron that, for as much as we know about the Burgess Shale and its remarkable, and sometimes utterly bizarre but beautiful creatures, we know very little.
“This is going to be very complimentary to what we have and what we know. You realize that we know nothing. We know very little and that means if you find another site it is likely you are going to have a mosaic combination of species that are common and that is not surprising.
“It is going to enrich us, but it is not the end point,” he said of the new site.
