Supplementary Table

NIGPAS Specimen numbers	Fossil locality	Coordinates
166593, 166617	Shankou Village, Anning	24°49’53’’ N, 102°24’47.9” E
166594, 166595	Yaoying Village, Wuding	25°36’01.2” N, 102°20’04.6” E
166596–166616	Ma’anshan Village, Chengjiang	24°40’37.2” N, 102°58’40.2” E

Table S1. Provenance of fossil material. Individuals from the Yaoying section are usually bigger, with a thicker body wall, and have a smaller ratio of apertural width to shell length than specimens from other areas. In the absence of other differentiating features, we consider these deviations to represent ecophenotypical variation within a single species, perhaps reflecting the increased energetics and predation pressure that accompany the shallower water depth reported at the Yaoying section (Zhao et al., 2012).

References

Zhao, F.-C., Hu, S.-X., Caron, J.-B., Zhu, M.-Y., Yin, Z.-J., & Lu, M. (2012). Spatial variation in the diversity and composition of the Lower Cambrian (Series 2, Stage 3) Chengjiang Biota, Southwest China. Palaeogeography, Palaeoclimatology, Palaeoecology, 346–347, 54–65. doi:10.1016/j.palaeo.2012.05.021