Fossilized feces unearthed across 35 global sites reveal that a prehistoric “fecal revolution” over half a billion years ago may have driven the Cambrian Explosion, according to an excremental study published in the journal Trends in Ecology and Evolution. Researchers found that the transformation in ancient animal waste coincided with the rise of complex marine ecosystems, providing a vital source of nutrients that fueled early life on Earth.
The Cambrian Explosion and the Role of Coprolites
During the Cambrian epoch, which began roughly 540 million years ago and lasted between 13 million and 25 million years, Earth experienced a rapid diversification of species. Most major animal groups emerged during this seminal epoch, alongside complex marine ecosystems and oceanic food chains that persist today, according to the study. While scientists previously proposed theories ranging from rising oxygen levels to predator-prey interactions, an international research team now points to waste matter as a driver of this evolutionary boom.
The researchers analyzed coprolite—fossilized feces—samples from 35 sites globally, noting a distinct transformation in the size, shape, and composition of species’ poop at the start of the Cambrian epoch. According to the study authors, microscopic pellets gave way to centimeter-scale coprolites containing crushed shells and other animal fragments as time progressed.
How Digestive Systems Sparked an Ecosystem Feedback Loop
This diversification of waste coincided with an uptick in increasingly complex digestive systems among early arthropods, which evolved specialized foreguts and digestive glands capable of handling varied diets. As these organisms consumed larger and more diverse meals, they deposited richer, more nutritious waste back into their environments. According to study author Russell Bicknell, an evolutionary ecologist at Flinders University, the importance of feces in ancient ecosystems is frequently overlooked next to rising oxygen levels and other factors.
Bicknell noted that these complex diets and food webs likely funneled more organic matter and nutrients into ancient oceans, fomenting exponential ecosystem growth during the late Ediacaran and early Cambrian periods. This primordial poop created an excremental circle of life that continues today, as surface marine organisms deposit waste that descends to fuel organisms that reside where the sun does not shine.
Did you know? Modern agriculture relies on a similar fecal feedback loop. Farms that grow our food use fertilizer comprised of animal dung, mirroring the nutrient-recycling mechanisms that first powered ancient marine ecosystems over 500 million years ago.
Frequently Asked Questions
What is coprolite?
Coprolite is fossilized feces. By analyzing coprolite samples from 35 sites around the globe, researchers can track changes in the size, shape, and composition of species’ poop.
How did ancient feces contribute to the Cambrian Explosion?
According to researchers, early arthropods developed complex digestive systems that allowed them to eat diverse diets. Their nutritious waste funneled organic matter and nutrients into ancient oceans, fueling exponential ecosystem growth.
Does this fecal feedback loop still exist today?
Yes. Surface marine organisms deposit waste that descends to feed organisms that reside where the sun doesn’t shine, and modern agricultural practices utilize animal dung as fertilizer to support crop growth.
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