Palaeontology collections manager at Cape Town museum on searching for fossils and listening to rap

Palaeontology collections manager at Cape Town museum on searching for fossils and listening to rap

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Zaituna Skosan has the eye. Where others see rock, her eye spots bone, where some notice a pebble, Skosan recognises the remains of an animal that died a quarter of a billion years ago.

On most fossil hunting expeditions Skosan can be seen walking the veld with her head down scouring the stones and rock that lie between the tufts of grass and shrub of the Karoo landscape. Often those hunts are done to the sound of her playlist.

“The music I listen to for field work is often rap, like Eminem, and I’ve been influenced by my husband, who listens to Tupac Shakur,” laughs Skosan.

With her trained eye, Skosan has found countless fossils and just recently those finds have contributed to our understanding of the worst extinction the world has ever experienced.

Back 252 million years ago, massive volcanic eruptions caused catastrophic climate change. It killed off most of the world’s species and quickly.

Fossil evidence suggests that within 100 000 years – a very short time geologically – 85% of species living in the oceans were wiped out. But what happened on land at the time has always been a bit of a mystery.

Lystrosaurus. An illustration showing Lystrosaurus during the end-Permian mass extinction. Picture: Supplied.

That is where Skosan and her colleagues came in.

Skosan, who is the palaeontology collections manager at the Iziko South African Museum was part of an international team of scientists who set out to study this catastrophic extinction event.

They examined the fossils of 588 animals that were found in what is now the Karoo Basin. These animals were alive during what is known as the Permian mass extinction. And many of these fossils came from the Iziko South African Museum.

“People assumed that because the marine extinction happened over a short period, life on land should have followed the same pattern, but we found that the marine extinction may actually be a punctuation to a longer, more drawn-out event on land,” said Pia Viglietti, a post-doctoral researcher at Chicago’s Field Museum, who was involved in the study.

The researchers created a database, then separated the fossils by age and grouped them into 300 000-year time intervals.

This allowed them a peek into which animals were appearing and disappearing.

“Ultimately, it lets us quantify how much extinction is happening and how quickly new species are appearing,” said Viglietti. “Instead of putting too much focus on any one fossil, you compile hundreds of observations roughly in the same time interval.”

One animal surprisingly appeared to thrive during the extinction.

Lystrosaurus was an early mammal herbivore that could grow to the size of a small cow.

Skosan has found many Lystrosauruses.

It is a mystery why Lystrosaurus survived, when many other animals didn’t. The suspicion is that it might have been able to adapt to the changing environment quicker.

What the likes of Lystrosaurus revealed to researchers was that the Permian extinction was far different on land than in the oceans. On land it was a more drawn out affair.

Skosan didn’t just find some of these fossils that helped reveal that terrible time in our prehistory, she was also instrumental in preparing them.

She is a fossil preparator, removing the hard rock that surrounds the specimens so they can be studied. Many of the fossils she finds, she prepares too.

A fossil of the dicynodont Lystrosaurus, a mammal relative that survives the end-Permian mass extinction event, is collected during fieldwork in South Africa’s Karoo Basin. Picture: Roger Smith

“That’s the joy of finding these fossils,” she says. “Because from the field to the prep table everything changes. You can find a fossil in the field and it’s embedded in rock, and you bring it to the prep table and you become the first person to see that specimen in 250 million years.”

The hope is that the new study might help us understand the climate change that is happening now and the extinction of species it is driving now.

But there is still more work to be done to fully understand the Permian extinction.

That means collecting more fossils, and that is what Skosan will be doing, hopefully a little later this year. She will once again be walking the veld, headphones on, and her eyes peeled, searching for the next discovery.

The Saturday Star



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