Appendix S1

Average dimensions and ratios of ventral valve of Eohadrotreta zhenbaensis from the Cambrian (Series 2) Shuijingtuo Formation of the Three Gorges area, South China, demonstrating the three ontogenetic development stages respectively

Appendix S4

Average dimensions and ratios of ventral and dorsal valves of Eohadrotreta? zhujiahensis from the Cambrian (Series 2) Shuijingtuo Formation of the Three Gorges area, South China, including the whole ontogenetic development stages

Table S2

Table S1 Details of Micromitra burgessensis dorsal valve specimens included in the analysis, including information regarding attachments, locality and individual measurements. WQ denotes the Walcott Quarry Shale Member and RQ denotes, the slightly younger Raymond Quarry Shale Member

Table S1

Table S1 Details of Micromitra burgessensis specimens included in the analysis, including information regarding attachments, locality and individual measurements. WQ denotes the Walcott Quarry Shale Member, RQ denotes, the slightly younger Raymond Quarry Shale Member and Ta refers to material collected as talus

Table S4

Table S3 CVA results of valve shape variation in the dorsal valves of M. burgessensis. In the results of the CVA, significant p values are indicated by light blue boxes

Topper et al. Raw coordinates for dorsal valves

Raw landmark coordinates used in dorsal valve analyses exported directly from MorphoJ. This data has not been transformed using Generalized Procrustes Analysis

Topper et al. Raw coordinates used in ventral valve analyses

Raw landmark coordinates used in ventral valve analyses exported directly from MorphoJ. This data has not been transformed using Generalized Procrustes Analysis

Tables 4-12

Localities and basic statistics for the described Associations (number of individual for each taxon estimated by methods outlined in the text

Appendix-dryad

Details of the sampled Fossil localities and the Palaeobiogeographical analysi