Kimming and Bicknell reported that fossilized fecal pellets from the Cambrian period may have supplied key nutrients that supported marine animal diversification. Early animals lived in nutrient‑poor surface waters, relying on dissolved chemicals; the evolution of digestive tracts allowed them to consume larger food items and excrete waste as solid pellets. The researchers analyzed coprolites recovered from 35 sites spanning 540 to 494 million years ago. The pellets contained organic carbon, iron, nitrogen and phosphorus, which the authors said could have increased nutrient availability in deeper ocean layers. They noted that pellet sizes ranged from microscopic to several centimeters and included shapes such as cylindrical, ellipsoid and circular forms. Larger specimens sometimes preserved fragments of shell or exoskeleton, indicating the diet of the animals that produced them. While most coprolites could not be linked to specific Cambrian taxa, the diversity of pellet morphology suggests a variety of organisms contributed to the waste record. The authors cautioned that additional evidence is needed to confirm that fecal nutrient input directly drove the observed increase in Cambrian biomass, and they called for further paleontological and geochemical investigations.