Van Roy P

Herpetogaster collinsi from the Cambrian of China elucidates the dispersal and palaeogeographic distribution of early deuterostomes and the origin of the ambulacrarian larva 1Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, China 2MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China 3State Key Laboratory of Palaeobiology and Stratigraphy, Chinese Academy of Sciences, Nanjing, China 4Paläontologie und...

Additional Information and Declarations Competing Interests The authors declare that they have no competing interests. Author Contributions Shigeaki Miyazaki conceived and designed the experiments, performed the experiments, analyzed the data, prepared figures and/or tables, authored or reviewed drafts of the article, and approved the final draft.

Discussion Orientation and occurrence of Brooksella in Conasauga shale beds If Brooksella is a hexactinellid sponge, it is very rare in shale beds compared to concretions and its orientation indicates that the central depression (previously interpreted as the osculum) and lobes are mostly facing downward into the sediment, either as a once-living sponge or oriented in that position after death.