The Burgess Shale records what life was like during the “Cambrian Explosion”. The Cambrian Explosion refers to the sudden appearance in the fossil record of complex animals starting about 540 million years ago. It may represent the most important evolutionary event in the history of life on Earth. The “explosion” is particularly remarkable because all major animal phyla (representing different body plans) appeared during this time, changing the biosphere forever.

Despite being separated by 505 million years, the structure of the food web from the Burgess Shale ecosystem is surprisingly similar to what we see in modern marine communities, although the individual species involved are clearly quite different. This suggests that basic feeding relationships were quickly established during the Cambrian Explosion and have remained relatively unchanged to the present.

Various feeding strategies are known in the Burgess Shale, including herbivory, detritus feeding (consuming decaying organic matter), suspension feeding (straining food particles suspended in water), and predation and scavenging. The accurate reconstruction of Anomalocaris canadensis led to the recognition that other large predators akin to Anomalocaris existed during that time (Laggania cambria first described as a sea cucumber and Hurdia victoria). The evolution of predation is regarded as one of the most significant feeding strategies to appear during the Cambrian Explosion. Today, predators play an important role in structuring animal communities by controlling prey populations. Although Anomalocaris was relatively rare in the Burgess Shale, its position in the food chain as a top predator made it an important part of the ecosystem.

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