CONSTRAINING THE ROLE OF AN EDIACARAN BIOMINERALIZER USING A MULTISCALE METHODOLOGY

Some of the earliest metazoans capable of biomineralization emerged during the Ediacaran Period (635 - 541 Ma). It has been suggested that one such biomineralizer, Cloudina, an abundant and globally distributed tubular organism, built structural frameworks and was a major component of microbial reef systems. This interpretation implies that metazoan reef building -- along with associated behaviors such as cooperative construction and environment modification -- emerged much earlier than previously thought.

We present an in-depth multiscale study of three fossil-bearing Ediacaran reef outcrops from Namibia and Canada. At each study area, we combine drone-assisted mapping, field observations, stratigraphic data, and three-dimensional reconstructions of Cloudina aggregates, produced using an automated serial grinding and imaging system in conjunction with a neural network image classification routine. We demonstrate that Cloudina was a minor component of microbial reef systems during the Ediacaran, that Cloudina aggregates likely are proximally sourced detritus, and that Cloudina had an easily deformable shell. On the basis of our reconstructions, we suggest that Cloudina may have had a life cycle analogous to present-day serpulid buildups.