An elongate worm from the Early Cambrian Chengjiang fossil Lagerstatte, Laojieella thecata gen. et sp. nov., is described on the basis of two specimens. Its unique body plan features a tapering, spinose proboscis, an elliptical theca on the posterior part of the trunk, and a caudal appendage. It is considered to be most closely related to cycloneuralians, especially priapulids, but cannot be firmly assigned to any known phylum. Some of the common characteristics like the spinose proboscis, shared by other proboscis-bearing fossil worms in the Early and Middle Cambrian, suggest that the common ancestor for cycloneuralians had a zoned proboscis. Based on the presence of sand grains in the gut, the animal is viewed as a detritus feeder probably with occasional preying.

Chengjiang Lagerstatte; Early Cambrian; worm; Laojieella

Northwest University