Exploring the Permian Extinction: Causes, Effects, and Survivors

About 252 million years ago, Earth experienced its most catastrophic extinction event. During the Permian-Triassic, roughly 90% of marine species and over 70% of terrestrial vertebrates died off.

What Caused the Permian Extinction?

At the end of the Permian, conditions became unsuitable for most life on land and in the seas. Many insects and plant species also went extinct during this time.

There are several theories about the cause of the Permian Extinction, often referred to as “The Great Dying.” The prevailing theory suggests that massive volcanic eruptions in what is now Siberia triggered the demise of large swathes of life on Earth. These eruptions released enormous amounts of carbon dioxide and other greenhouse gases into the atmosphere. This led to extreme global warming, ocean acidification, and a drastic reduction in oxygen levels in the seas. The eruption caused ocean warming and acidification, which collapsed food webs on land and sea. Resulting toxic volcanic gases caused environmental stresses, and wildfires added to the widespread extinction.

An Alternate Extinction Theory

Researcher Bruce Rubidge, a leading paleontologist specializing in the Karoo Basin's fossil record, has proposed that the extinction of land fauna occurred over nearly a million years, rather than in a single instant. This slow-burn collapse suggests that climate change and habitat loss were significant causes.

Scientists are still searching for answers.

What The Karoo Tells Us About the Permian Extinction

The Permian–Triassic mass extinction is recorded in stone in the Karoo Basin of South Africa. This area is rich in fossils of terrestrial animals from the Permian and Triassic geological periods. The Karoo's fossil layers allow for fine-scale tracking of changes in species diversity and ecological turnover before, during, and after the extinction. This makes the Karoo one of the few places where scientists can accurately study the Great Dying that occurred on land during this time.

Permian Extinction Species Survival and Losses

What species suffered the greatest losses during the Permian Extinction, and which ones survived?

Marine and Terrestrial Survivors of the Permian Extinction

• Early ancestors of mammals, such as synapsids, therapsids, and archosaurs (ancestors of crocodiles and dinosaurs, and eventually birds), survived and diversified after the mass extinction.

• Among the most iconic survivors of the Permian-Triassic extinction is Lystrosaurus—a dicynodont whose dominance rose sharply after the Great Dying. There are many theories to explain its survival, including the ability to hibernate, burrow, or live semi-aquatically.

• Primitive aquatic predatory amphibians, such as temnospondyls, survived the extinction likely due to their ability to exploit freshwater prey and habitats.

• Certain groups of bivalves (e.g., clams), shelled cephalopods, and some gastropods (snails) also survived.

• Freshwater and salt-tolerant fishes survived, with some increasing in diversity.

• Small reptiles called procolophonids were among the few surviving reptile groups.

  
  

Marine Extinctions During the Permian

• Trilobites completely vanished.

• Rugose and tabulate corals, along with most sponges, disappeared.

• Blastoids and many crinoids were wiped out.

• Brachiopods and bryozoans suffered severe losses, with many going extinct.

• Gastropods experienced catastrophic declines, and many went extinct.

  
  

Terrestrial Extinctions Caused by the Great Dying

• More than two-thirds of amphibian species, including large amphibians, disappeared.

• "Sail-backed" synapsids became extinct.

• Gorgonopsians and most, if not all, predatory therapsids went extinct.

• Large land-dwelling reptile herbivores suffered heavy losses.

• Among the most unusual extinctions was the loss of one-third of insect species.

  
  

Permian Extinction Scholar Bruce Rubidge

Among the most important researchers on the subject of the Permian mass extinction is South African scientist Bruce Rubidge. Rubidge has pioneered the dating framework that aligns Karoo biodiversity changes with absolute time, making the Karoo record internationally benchmarked.

The Karoo’s fossil treasures, studied in depth by Bruce Rubidge and colleagues, provide powerful evidence for how life on land endured, adapted to, and eventually recovered from the world’s most catastrophic extinction event.

Join Bruce Rubidge and his colleagues to see and study fossils and geology of the Permian Extinction on the Ancient Odysseys Ancestors of Mammals Itinerary.

The Importance of Studying Extinctions

Understanding extinction events like the Permian Extinction is crucial. They provide insights into how life on Earth responds to drastic changes. By studying these events, scientists can better understand current biodiversity crises and climate change impacts.

Lessons from the Past

The Permian Extinction teaches us about resilience. Some species adapted and survived, while others did not. This highlights the importance of adaptability in the face of environmental challenges.

Future Research Directions

Ongoing research in paleontology and climate science is essential. Scientists continue to explore the factors that led to the Permian Extinction and how similar events might be prevented in the future.

Conclusion

The Permian Extinction remains a pivotal moment in Earth's history. By studying it, we gain valuable insights into the resilience of life and the importance of protecting our planet's biodiversity.