Overview
- A systematic review published Tuesday in Trends in Ecology & Evolution by Julien Kimmig and Russell D.C. Bicknell frames a rapid increase in fossilized feces as a plausible, complementary contributor to the Cambrian explosion.
- The authors compiled coprolite and gut-fossil records from more than 35 global Cambrian deposits and report growing size, shape variety, and digestive complexity through the interval.
- They propose a mechanism in which sinking fecal pellets moved carbon, nitrogen, phosphorus and iron through the water column, making nutrients more available across marine habitats.
- The review argues this process could create a positive feedback—larger, more complex animals produced bigger feces, which boosted nutrient redistribution and supported richer ecosystems.
- The paper reframes existing data rather than presenting new fieldwork and calls for targeted tests such as sediment geochemistry, quantified flux modelling, and focused fossil analyses to evaluate the hypothesis.