Burgess Shale type fauna

A number of assemblages bear fossil assemblages similar in character to that of the Burgess Shale. While many are also preserved in a similar fashion to the Burgess Shale, the term "Burgess Shale type fauna" covers assemblages based on taxonomic criteria only

Extant
The fauna of the middle Cambrian has a cosmopolitan range. All assemblages preserving soft-part anatomy have a very similar fauna, even though they span almost every continent.[2] The wide distribution has been attributed to the advent of pelagic larvae.

Cosmoposition
The fauna is composed of a range of soft bodied organisms; creatures with hard, mineralised skeletons are rare, although trilobites are quite commonly found. The major soft-bodied groups are sponges, palaeoscolecid worms, lobopods, arthropods and anomalocaridids.[2] Assemblages are typically diverse, with the most famous localities each containing in the region of 150 described species.[2] The fauna of the Burgess Shale lived in the photic zone, as bottom-dwelling photosynthesisers are present in the assemblage.