Vetulicola rectangulata, an Enigmatic Fossil from Chengjiang

This unusual fossil is Vetulicola rectangulata, a member of the Vetulicolians, an enigmatic group that some scientists place in their own phylum (Phylum Vetulicolia). They are thought to have been swimmers that either were filter feeders or detritivores. One researcher places them with the Urochordates based on putative affinity with the Phylum Chordata. At present, there is no agreement as to their systematic placement. This specimen comes from the Chengjiang Biota, and is thus slightly older than the Burgess Shale Fauna of British Columbia. This one is quite detailed, with both the abdomen and the carapace present. Some of the exterior of the carapace is gone, allowing you to see some of the interior structure. The Chengjiang fossils comprise the oldest, diverse metazoan faunal assemblage above the Proterozoic-Phanerozoic transition, and thus the fossil record’s best data source for understanding the apparently rapid diversification of life known as the Cambrian Explosion.