Burgess Shale–Type Localities:
The Global Picture
James W. Hagadorn
INCREASED AWARENESS OF THE BURGESS SHALE BIOTA HAS led to systematic searching for and accidental discovery of a plethora of soft-bodied faunas throughout Lower and Middle Cambrian strata all across the globe. Many of these soft-bodied forms are known from the Burgess Shale or are closely allied with taxa from the Burgess Shale. Over the past 30 years, these Burgess Shale–type faunas have been documented throughout the Cambrian, as well as from Ordovician and Silurian strata. In some cases, such as Chengjiang (Chapter 3), these faunas have actually begun to approach or eclipse the paleontological impact of the original Burgess quarries.
Furthermore, as this awareness peaked, many obscure, previously undescribed, or isolated soft-bodied specimens from other deposits were recognized as Burgess Shale–type faunas and have been placed into a larger-scale paleobiologic context (e.g., Parker Slate and Kinzers Formation biotas) (Conway Morris 1993; Garcia-Bellido Capdevila and Conway Morris 1999). Although the faunal abundance and preservation in many of these deposits is less than that in the Burgess Shale, many of them have provided additional information about soft-bodied paleocommunities that inhabited a wide range of paleoenvironments during the Cambrian explosion.
Like those in the original locality, Burgess Shale–type faunas are usually preserved in shales, exhibit a range in preservation from exceptional articulated specimens to disarticulated fragments, and were formed by a combination of taphonomic scenarios (e.g., obrution and stagnation). In general, Burgess Shale–type deposits are dominated by nontrilobite