The Permian Extinction: South Africa’s Window into Species Extinction

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. At this time, many insects and plant species also went extinct.

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

An alternate extinction theory

Researcher Bruce Rubidge, the leading paleontologist specializing in the Karoo Basin's fossil record and its global significance has proposed that the extinction of land fauna occurred over nearly a million years and not a single instant of demise. This slow-burn collapse suggests that climate change, and habitat were causes.

Scientists are still looking 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 very 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 that 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 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) 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, and most sponges disappeared

• Blastoids and many crinoids were wiped out

• Brachiopods & Bryozoans suffered severe losses; and many went extinct

• Gastropods suffered 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 died out

• 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 and scholars 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.