"The Fossils of the Burgess Shale" by Derek E.G. Briggs, Douglas H. Erwin, Fredrick J. Collier. Smithsonian Institution Press 1994.
by Jeff Hecht. Charles Scribenr's & Sons
Llocated in British Columbia, Canada, the Burgess Shale dates back to the Paleozoic era in the mid Cambrian age (over 540 million years ago). This is about 305 million years before the first dinosaurs. The Burgess Shale is unique in the large number of fossils of soft-bodied organisms.