Temporal heterogeneity in the animal fossil record driven by proliferation of microbial collagenases.

Proliferation of microbial collagenases is linked to the decline of exceptional soft-tissue preservation in the animal fossil record.

• Why it matters: Understanding the causes of non-uniform fossil preservation helps clarify the biases and limitations of the fossil record, especially regarding soft tissues, which are rarely preserved.
• What they did: The study analyzed collagenase gene trees and a time-calibrated phylogeny, revealing that collagenases originated billions of years ago and proliferated around the time of early animal diversification.
• The result: Findings suggest that the spread of collagenase-producing microbes coincided with the decline in soft-tissue fossilization, indicating microbial activity influences preservation patterns over geological time.