Giant predatory amphibian Gaiasia jennyae in north-west Namibia

More than two metres long. The head as big as a toilet lid. The mouth spiked with teeth. 300 million years ago, it was one of the largest predators on the mainland: the giant amphibian Gaiasia jennyae . Big surprise: it also lived in areas that were very cool at the time, such as the area that is now Namibia.

This is confirmed by one of three known fossils of Gaiasia jennyae found in north-west Namibia. As BBC Discover Wildlife reported, a team of six researchers led by Claudia Marsicano (University of Buenos Aires) has now used this fossil to describe the only known species of its genus.

Marsicano & Co have named the genus after the rock formation in which the fossil was found: The Gai-As Formation in the Huab Basin in north-west Namibia. They named the species in honour of the achievements of palaeontologist Jennifer (Jenny) Clack, who died in 2020.

More like a salamander or a moray eel?

Whether Gaiasia jennyae was more like a giant salamander or a giant moray eel is not entirely clear. So far, researchers have not found any remains of the limbs.

The body length is also unclear. The three known fossils of the giant amphibian do not have a complete skeleton. So we can only speculate. Depending on the shape of the body, the length is estimated at two to four metres.

The broad, flat skull was around 60 cm long. When the water-dwelling predator opened its mouth, suction was created. The prey was sucked in, grabbed with the sharp teeth and crushed. This indicates that Gaiasia jennyae ambushed its prey instead of chasing it.

Actually too cool for Gaiasia jennyae

The discovery of the fossil in Namibia is astonishing. Palaeontologists classify Gaiasia jennyae as a stem-tetrapod (terrestrial vertebrates) that fell victim to the mass extinction when the tropical rainforests collapsed.

However, this occurred at the end of the Carboniferous period around 305 million years ago. The giant amphibian is therefore one of the very few species of these stem tetrapods that survived the catastrophe.

Palaeontologists were also surprised that Gaiasia jennyae was found in north-western Namibia. Around 300 million years ago, the area had a cool climate with seasons in which it got really cold.

In addition to Gaiasia jennyae, another fossil from the Permian period (from around 300 million years ago) can also be found in Namibia: Mesosaurus. The crocodile-like reptile, which was up to one metre long, lived in shallow waters and the shore zones of lakes see Wikipedia. One of the sites where its fossils were found is east of Keetmanshoop.

You can find out more about the giant amphibian Gaiasia jennyae in a recent article on Wikipedia [https://en.wikipedia.org/wiki/Gaiasia]. The article in the science magazine 'Nature' is also freely accessible.

Sven-Eric Stender