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Episode 208 – The Karoo Supergroup

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Southern Africa is home to an extraordinary sequence of rock formations that record more than 100 million years of evolution, extinction, and an incredible diversity of ancient life. This episode, we explore the Karoo Supergroup.

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Fossils of the Karoo

The Karoo Supergroup is a sequence of geologic formations in and around the Karoo region of southern Africa. Rocks of the Karoo Supergroup cover around 300,000 square kilometers and span more than 100 million years of time from the Late Carboniferous to the Early Jurassic. It is one of the most impressive uninterrupted records of geologic time in the world.

Map showing the various geologic formations and assemblages (AZ = assemblage zone) of the Karoo Supergroup across southern Africa. Image from Roger Malcolm Harris Smith et al 2020

The extensive geologic formations of the Karoo Supergroup are full of extraordinary fossils, including well-preserved plants, invertebrates, trace fossils, mammalian ancestors, early dinosaurs, ancient amphibians, and much more. The time span covered by this geologic sequence includes the rise of mammals and dinosaurs, as well as two of the most devastating mass extinctions in Earth history: the end-Permian and the end-Triassic, making it an incredible resource for studying these events.

A paleoart mural depicting fossil animals from Late Permian deposits near the village of Nieu Bethesda, displayed at the Kitching Fossil Exploration Centre.
Art by Gerhard Marx. Image from Bordy et al 2023.

Modern scientists began documenting Karoo fossils in the early 1800s. In the mid-1900s, Karoo fossils – especially plants and animals that were suspiciously similar to fossils in South America and Antarctica – provided crucial evidence for the concept of continental drift, and later plate tectonics. These days, thousands of Karoo fossils are curated at museums around the world, and many more continue to be discovered.

Fossil cynodonts from the Early Triassic “Lystrosaurus graveyard.”
The skeleton belongs to Galesaurus, and the inset skull belongs to Thrinaxodon. Image from Bordy et al 2023

The deepest layers of the Karoo Supergroup document the waning of Carboniferous glaciation during the assembly of Pangaea, and the subsequent rise of early synapsids in the warm climates of the Permian. Glossopteris and other fossil plants left behind major coal beds. Karoo fossils document the lead-up to the end of the Permian, the major extinction events that brought the Paleozoic Era to a close, and the gradual recovery of ecosystems afterward.

Diagrams of fossil footprints of dinosaurs and ancient amphibians from Early Jurassic deposits near the town of Moyeni in Lesotho. Image from Bordy et al 2023.

The upper portions of the Karoo Supergroup chronicle the beginning of the Age of Reptiles, including the diversity of crocodile-cousins and ancient amphibians in the Triassic, and their eventual replacement by diversifying dinosaurs in the Jurassic. In Karoo rocks, dinosaurs left behind not only skeletons, but also footprints, eggs, and more. The Karoo Supergroup is capped by the vast basalt layers of the Karoo Large Igneous Province, which spilled lava across the landscape as Pangaea split apart.

Massospondylus eggs and embryos from the Early Jurassic Rooidraai Dinosaur Nesting Grounds in Golden Gate Highlands National Park. Image from Bordy et al 2023.

There is an exhaustive list of amazing fossil localities within the Karoo Supergroup. Some of them have been extensively sampled, while others have only recently been discovered. Some of these sites are legally protected and preserved for future research, and a few even have museums or visitors’ centers built near or around them.

Learn More

Selected Karoo geoheritage sites of palaeontological significance in South Africa and Lesotho (technical, open access)
Life and land engulfed in the late Early Jurassic Karoo lavas of southern Gondwana (technical, open access)
Introduction to the tetrapod biozonation of the Karoo Supergroup (technical, open access)

Karoo in the News
Episode 196: An early tetrapod apex predator
Episode 180: Bird-like footprints, way older than birds
Episode 163: Trace fossils show ancient amphibian swam like a croc
Episode 151: Lystrosaurus drought death beds
Episode 148: Mbiresaurus, the oldest known African dinosaur
Episode 126: The evolution of tusks

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