The ocean floors hosted a silent revolution that transformed life on Earth. According to a new study, prehistoric worms released oxygen by burrowing into marine sediments, thus contributing to an explosion of biodiversity during the Ordovician.
Over a period of 30 million years, prehistoric worms may have been the silent players in one of the greatest diversifications of life. Their burrowing released oxygen, triggering the Ordovician Biodiversity Explosion.
Researchers from
Johns Hopkins University discovered that the mixing of sediments by worms and other invertebrates released oxygen into the ocean and atmosphere, initiating the Ordovician Biodiversity Explosion. These findings were published in the journal
Geochimica et Cosmochimica Acta.
By reexamining the chemistry of ancient oceans, the team updated models to detail the increase of oxygen over hundreds of millions of years. They found that sediments mixed by worms contained more pyrite, a key mineral for oxygen accumulation.
The results challenge previous assumptions about the relationship between pyrite and sediment mixing. Researchers found that even a small disturbance of sediment in low-oxygen waters could expose buried pyrite to enough oxygen to form more pyrite.
Applying this new relationship to existing models, they discovered that oxygen levels remained stable for millions of years before significantly increasing during the Ordovician. This increase in oxygen likely contributed to the Ordovician Biodiversity Explosion.
This research sheds light on the link between oxygen levels and major evolutionary events, paving the way for a better understanding of the forces that shaped the diversity of life on Earth.