Canada is home to Burgess Shale: an expansive fossil field that contains a diverse array of preserved organisms dating all the way back to the Middle Cambrian, 505 million years ago. There are two well-known sites: one in the Yoho National Park and another 42 km (26 miles) away at Kootenay National Park. Another site has been discovered in Kootenay and could be the richest fossil site ever discovered. The announcement comes from lead author Jean-Bernard Caron of the University of Toronto and was published in Nature Communications.

Burgess Shale was discovered in 1909 and is world-renowned for its exceptionally well-preserved fossils. Over the last century of thorough exploration, there have been about  200 different species identified. This new site, dubbed “Marble Canyon,” just might put that figure to shame.

Researchers have only been digging at the site for 15 days but already more than 50 species have been identified - including some entirely new species. Thousands of specimens have been uncovered, a large number of which appear to be arthropods. 

The fossils discovered at this site have much to teach us about the Cambrian Explosion, which is when life first really began to diversify. Prior to the Cambrian life on Earth had been relatively simple. Among the arthropod species represented are some that had only been seen before in the Chengjiang fossil beds in China. Because fossils from that site represent the early Cambrian about 10 million years prior, it gives new insight to the global range of certain ancient animals and helps to establish a timeline of how long the species lived. The site also confirms that Pikaia, which was first discovered at the Yoho site in 1911 and looks quite similar to a modern lancet, is the common ancestor of all vertebrates.

Currently, the exact location of the new fossil site within the park has not been released, as the Canadian park officials wish to keep it free from visitors for the moment. The researchers have stated that they are eager for summer to return so that they may continue their field work. Though time and more excavation will ultimately tell the full importance of this new Burgess Shale site, the preliminary numbers indicate that it is well on its way to becoming one of the most important fossil site discoveries in the world.