Stanford researchers link mass extinction of marine life to heat and low oxygen levels

On July 10, 2026, researchers from Stanford University unveiled a study explaining how intense heat and reduced oxygen levels during the Permian–Triassic extinction event led to the mass extinction of several marine species. This research provides insight into the evolutionary impacts of the event, known as the "Great Dying," which occurred approximately 252 million years ago.

Understanding the Great Dying and Its Impact

The Permian–Triassic extinction resulted in the loss of 96% of marine species and 70% of land animals. The study highlights that while many marine groups like brachiopods and crinoids were nearly wiped out, others, including mollusks, largely survived. This disparity in survival rates is attributed to the metabolic capabilities of these organisms.

Lead author Jose Andres Marquez, a former Ph.D. student, stated, "Our findings show that, across different organism groups, extinctions happened at much higher rates for those more vulnerable to increases in water temperature and decreases in oxygen availability." This research offers a new perspective on why certain species thrived while others perished.

The Role of Volcanic Activity

The study emphasizes that the extinction event was exacerbated by a surge of volcanic activity that released vast amounts of greenhouse gases like carbon dioxide and methane into the atmosphere, leading to warming oceans. The resulting conditions were inhospitable for many marine species, particularly those with slower metabolisms.

According to Andrew Zinin, chief editor, this study serves as a critical reminder of the potential consequences of current climate change. He remarked, "The biggest mass extinction of all time started from a world that is very similar to today in having a relatively cool, relatively well-oxygenated ocean, and then there was a giant injection of carbon dioxide into the Earth system."

Lessons for Today's Climate Crisis

The findings of this study draw parallels between the ancient extinction event and the current climate crisis caused by human activities. Researchers warn that the physiological responses of ancient marine life can inform our understanding of how modern ecosystems might respond to ongoing environmental changes.

The research team built upon previous studies from 2018 that indicated oxygen loss and warming as primary drivers of the Great Dying. By incorporating physiological data from both extinct and surviving species, this study deepens the understanding of extinction dynamics.

• 96% of marine species lost during the extinction
• 70% of land animals extinct
• Surviving groups include mollusks, fish, and echinoderms
• Volcanic activity linked to greenhouse gas emissions