We took a side trip into neighboring Yoho National Park, to the site where the Burgess Shale Fauna were discovered in 1907 by Charles Walcott. The area had been reknown since 1886 as a hotbed for trilobite fossils, but Walcott found something else amazing. In a stretch of rock called the Burgess Shale, he found the fossilized remains of strange and glorious creatures which lived 515 million years ago.
Usually when a creature is fossilized, only the hard parts like bones are preserved. But the amazing animals in the Burgess Shale show all their soft parts -- eyes, mouths, legs, and other strange appendages at a time before bones had even evolved. Some of the creatures included Anomalocaris, a two-foot carnivorous shrimp-like creature, and Hallucinagenia, an animal made up of tentacles and spikes which it walked upon.


For more info on the Burgess Shale, check out Stephen J. Gould's book Wonderful Life.