Burgess Shale

From EvoWiki

The Burgess Shale is a Lagerstatten (soft bodied fossil fauna) in the Yoho national park, BC Canada. The fauna was discovered by Charles Walcott (at the time director of the Smithsonian institute) in August 1909, 8000 feet above sea level, and 3000 feet above the town of Field, on the ridge between Mt. Field and Mt. Waptia. The Burgess Shale yielded a large collection of well preserved marine Cambrian organisms, from a time shortly (in geological time) after the "Cambrian explosion", a unique period of time when multicellular life was diversifying rapidly.

The fossils of the Burgess Shale, which had been flattened as sediments turned to rock, were initially interpreted by Walcott, and later Percy Raymond (1930), as being primitive ancestors of modern species, but in the 1970s a team including Harry Whittington, Simon Conway Morris, Derek Briggs, Chris Hughs, David Bruton and Des Collins studied the Burgess fossils in greater detail than before and came to a different conclusion - that (many of) the Burgess organisms do not have any modern ancestors, and many contain unique designs bearing no resemblance to any other known species, past or present.

Some genre unique to the Burgess fauna or rocks of Burgess age include Marella, Yohoia, Wiwaxia, Anomalocaris, Opabinia, Burgessia, Naraoia, Aysheaia, Odontogriphus, Dinomiscus, Amiskwia, Hallucigenia, Branchiocaris, Canadaspis, Sidneyia, Odaraia, Molaria, Habelia, Sarotrocercus, Actaeus, Alalcomenaeus, Emeraldella, Leanchoilia, Santacaris and Nectocaris.