Undressing and redressing Ediacaran embryos (Reply): Palaeontology

Xiao et al . 1 suggest that the presence of a textured capsule surrounding some Doushantuo globular microfossils calls into question the alternative interpretation of these structures as giant sulphur bacteria similar to modern Thiomargarita 2 . However, the outer coatings illustrated by Xiao et al . 1 are similar morphologically to known bacterial features, and the texture, location and thickness change of the capsule is inconsistent with that of a fertilization envelope. We are therefore not convinced that the bacterial hypothesis has been falsified.