Essay --

With its abundance of genera, the Burgess Shale is one of the world’s most important fossil fields. It’s discovery in 1909 led to over 100 years of paleontological study in the Canadian Rockies, a majority of which has been carried out in two quarries known as the Walcott and Raymond quarries (Hagadorn, 2002). Though he was originally in search of trilobites in the Burgess Shale Formation, paleontologist Charles Walcott also discovered a diverse group of soft- and hard-bodied fossils, from algae and sponges to chordates and cirripeds (Hagadorn, 2002). Soft-bodied fossils are incredibly rare due to their delicate structure and susceptibility to decay, so it is hard-bodied fossils that more regularly occur in fossil findings. However over 75,000 soft-bodied specimens have been found in the Burgess Shale formation (Hagadorn, 2002). These specimens are preserved in layers of shale formed from deposits of fine mud. One of the most significant species discovered is the Pikaia gracilens. Believed to be an early chordate, the Pikaia gracilens existed very close to the beginning of the evolutionary path that ultimately lead to humans (McGraw-Hill Encyclopedia, 2006). The Burgess Shale formation is characteristically informative of significant events in the evolutionary path of multiple organisms. Its abundance of exquisitely preserved Lagerstà ¤tte has inspired paleontologists to refer to this mode of preservation as ‘Burgess Shale-type’ (Williams, 2009). The Burgess Shale is located in British Columbia’s Yoho National Park; Part of the ancient landmass called Laurentia (Scott, et al., 2000). Fossils found within the formation dating back 545-525 million years ago represent original species from the Cambrian explosion, a relativel... ...deposition and blanket of sediment kept the organisms compressed with little exposure to oxygen for decay. If life was predominately terrestrial during the Cambrian, the organisms predictably would have been left untouched after death long enough to decay, preventing the fine preservation of many soft-bodied organisms. Fortunately enough, it was marine life that dominated the Cambrian (Scott, et al., 2000). Over the past century, the Burgess Shale has revealed important information about the development of earth’s history. The excavation of the Burgess Shale formation provided evidence for what was once just a theory in evolution. The taphonomic findings of the Burgess Shale have played a significant role in understanding the large diversity that resulted from the Cambrian explosion, advancing the study of evolutionary assemblages for Paleontologists worldwide.