Africa Wild

A past buried in the Karoo town of Sutherland holds portents for our survival as a species



Seed cones of the Glossopteris plant preserved with its pollen cones, solve a 200-year-old botanical mystery as to the reproduction of the long-extinct plant which formed most of the economically important coal reserves used today, says Dr Rose Prevec. (Photo: Rose Prevec)

By Jamie Venter | 6 Dec 2022

The discovery of exquisitely preserved plant and insect fossils may shed light on previously unknown life of the past. But these tiny fossils may have an even bigger story to tell: the story of a mass extinction believed to have been driven by greenhouse gas emissions that draw an eerie parallel to today’s climate crisis.
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Sutherland is well known for its great expanse of fossil fields, which are littered with the bones of dinosaurs that once roamed the landscape. It is also known for being cold — really cold. This reputation is well-earned, but the large reptilian remains of life before humans make the Karoo’s bitter cold worthwhile for tourists and palaeontologists alike.

Just a short way out of town, on a small site no larger than six by five metres, thousands of remarkably well-preserved fossilised plants, birds and insects may hold the key to understanding extinction events of the past and assist scientists in predicting the effects of the current climate crisis. This is according to new research conducted by paleobotanist Dr Rose Prevec.

“Sutherland is known for its vertebrate fossils; the bones preserve really well in that area,” said Prevec. But despite attempts to locate evidence of fossilised plant life in the area, there have been very few well-preserved discoveries. This is because the soft tissues that predominantly make up plants and insects tend not to fossilise at all, except under very unique circumstances.

‘Miraculous’ find

“It was really miraculous to find any plants, let alone something so beautifully preserved,” said Prevec.

The site — which was originally discovered in 2009, but on which excavations only began in 2016 due to a lack of interest in funding the dig — has unearthed thousands of plant and insect fossils, some of which are new to science.


This 40-million-year-old fossilised leech found in the Karoo could be the oldest freshwater leech discovered, says paleobotanist Dr Rose Prevec. (Photo: Rose Prevec)

The fossils unearthed reveal life that existed in a lakeshore ecosystem, 266 million years ago, states the research paper.

Some of the discoveries include a fossilised leech, mosses, liverworts, winged insects, mites and leaves of plants such as Glossopteris, which formed most of the economically important coal reserves used today.

The leech may be the oldest freshwater leech in the world and is dated as far back as 40 million years, explains Prevec.

Although the fossils may be small, they are compelling.

When the researchers found the first mite, they believed it to be a seed, explains Prevec. But, “we looked closer and these legs appeared and it was this giant tick-looking thing. And then there was a lot of excited shrieking,” says Prevec.

“These fossils are important because they fill in a gap in the fossil record,” says Prevec.

Currently, scientists have a good idea of the vertebrate animals that existed because they preserve so well and are found in abundance, but there is very little understanding of the plant and insect life from the same ecosystems.

The discoveries of these fossils will help fill in the gaps in scientists’ understanding of evolution of these insects and plants, explains Prevec.

This is an important gap to fill, because, as well as contributing to scientists’ understanding of evolution, it also has implications for current climate change research.

To understand an “ecosystem, measure biodiversity and how it changed with shifting climates, we need to look at the small things and the green things”, says Prevec.

“If you were to study a modern ecosystem and wanted to understand climate change, you wouldn’t look at six antelope and a lion,” says Prevec.

“It’s really the plants, the insects, the small things, the things that are at the base of the food chain, that really tell you what’s going on with an ecosystem.”


Thousands of remarkably well preserved fossilised plants, birds and insects were discovered in the Karoo, some of which showed intact wings, hairs and even coloration. Such well preserved invertebrate fossils, as pictured above, are extremely rare to find, says paleobotanist, Dr Rose Prevec. (Photo: Rose Prevec)

Understanding this ecosystem and the fossils it left behind is particularly important because of their place in Earth’s history prior to a major extinction event.

The fossilised Glossopteris, as an example, became extinct at the end of the Permian Period. The “Great Dying”, was a mass extinction event that is thought to have been driven by greenhouse gas-induced climate change.

Understanding this extinction event could help scientists better predict the impact of the world’s current unsustainable carbon emissions and latest climate crisis, says Prevec.

But, as it stands, in South Africa very little research is being conducted in the area of paleobotany. There needs to be a greater understanding of past ecosystems as a whole to understand the ecosystem collapse seen during extinction events, but that has been missing from research, explains Prevec.

“Historically, our focus has always been vertebrates… most people are drawn to things with teeth.”

Lonely field

Prevec is one of just three paleobotanists in the country and the only one working with macro plants instead of microscopic plant structures.

“I am pretty much the only one looking at leaves in South Africa, which is a crime,” says Prevec. “For one person to look at all the leaves on the botanical record, for the whole of time, right across the country, is just crazy.”

“It’s lifetimes of work,” says Prevec. But, “if you don’t know what the ecosystems are doing before the extinction event, how do you evaluate what actually changes during that event?”

As climate change has steadily become a more pressing matter on the agenda, people have become more aware of ecosystems and how ecosystems change, says Prevec.

As a result, “more people are recognising the need to know what happened in the past; what happened with an extinction event that looks very similar to what we face now, and how that can tell us about what is happening today”. DM/OBP

New discovery: fossilised giant zebra tracks found in South Africa


An illustration of two giant Cape zebras alongside a much smaller plains zebra. Maggie Newman

Published: March 16, 2023 by Charles Helm, Research Associate, African Centre for Coastal Palaeoscience, Nelson Mandela University

Tens of thousands of years ago, a huge horse species walked, trotted and galloped across the shifting sands of what is today South Africa’s Cape south coast.

The Giant Cape Zebra (Equus capensis) weighed an estimated 450 kg. Its extant relatives in southern Africa are far smaller: the plains zebra weighs between 250 and 300 kg and the Cape mountain zebra is the smallest of all zebra species, with a mass of between 230 and 260 kg.

The Giant Cape Zebra became extinct just over 10,000 years ago. This may have been partly because of the loss of its preferred habitat of extensive grasslands, as rising sea levels flooded the vast Palaeo-Agulhas Plain. But until now it hasn’t been clear how common the species was on the Cape south coast because its body fossils are predominantly from southern Africa’s west coast.

That’s where ichnology – the study of tracks and traces – comes in. Since 2007 our team has documented more than 350 fossil vertebrate tracksites along a 350 km stretch of the Cape south coast.

Now, by studying the tracks left by those galloping, walking and trotting zebra so long ago, we’re able to say that they must have been a fairly regular sight on the landscape of the Cape south coast, and were more common than was suggested by the body fossil record in the area. This confirms the capacity of the body fossil record and ichnology to complement each other.

Being able to look back in time in this way doesn’t just help scientists to better understand ancient landscapes. It’s also an important part of understanding what’s changed over time and the effects of climate change and humans.

Zebra crossings

In our recently published article we described how we have identified 26 equid tracksites – including tracks belonging to Equus capensis – in aeolianites (cemented dunes) on South Africa’s Cape south coast in the vicinity of towns like Still Bay and Plettenberg Bay.

This is especially exciting because equid tracks dating to the Pleistocene epoch, which started 2.6 million years ago and ended about 11,700 years ago, are rare. In fact, our finds mean that the Cape south coast accounts for the majority of the sites known globally from this time period (other sites are in Kenya, Ethiopia, Italy, the Arabian Peninsula, and the Americas).

Thirteen of the tracksites we found contain tracks 12 cm or greater in length, and eight contain tracks 10 cm or less in length (in the remaining five cases we could not access the tracks for measurement). Well preserved equid tracks are fairly distinctive: features include an unbroken hoof wall and what is known as a “frog” towards the centre of the track.


The site with the long Giant Cape Zebra trackway. Jan De Vynck

We were able to attribute the large tracks to Equus capensis, and the small tracks to the quagga (Equus quagga quagga), the plains zebra subspecies that became extinct in the 19th century.

One of the Giant Cape Zebra sites comprises a single trackway containing 12 tracks. Another contains two probable quagga trackways that intersect at right angles, respectively containing ten and six tracks. We informally dubbed this the “zebra crossing”. Such long fossil equid trackways are especially rare, as equids are often gregarious (resulting in trampled areas) and isolated trackways are unusual.

One other African example of a long equid trackway is from Laetoli in Tanzania from the older Pliocene Epoch. Sadly, the finest such site was in Nevada in the US, where a 50,000 year-old equid trackway contained 28 tracks – but it was covered in the 1930s during prison construction and is no longer accessible.

Through our Optically Stimulated Luminescence dating program, we have established an age range for the equid tracksites from about 161,000 years to about 43,000 years.

Looking back – and ahead

Identifying and reporting the tracks of the Giant Cape Zebra allows us not only to imagine its presence on the Cape south coast many thousands of years ago, but also reminds us of how extinction often follows in the wake of climate change. And it allows scientists like ourselves working in southern Africa to contribute substantially to a relatively sparse global record of such sites.

Fossil snake traces: another world-first find on South Africa’s Cape south coast

October 5, 2023 5.49pm - Charles Helm, Research Associate, African Centre for Coastal Palaeoscience, Nelson Mandela University

Hayley Cawthra, Specialist Scientist, Council for Geoscience


Puff adders leave linear, sometimes slightly undulating traces. EcoPrint/Shutterstock

Snakes are familiar, distinctive – and often feared – reptiles. And they’ve been around for a long time: body fossils found in the UK, Portugal and the US stretch all the way back to the late Jurassic period, about 150 million years ago.

Until now, though, there hasn’t been a single description of a surface fossilised snake trace – a mark on a surface that’s become cemented and re-exposed over time – anywhere in the world.

There are probably several reasons for this. One is that the tracks of large quadrupeds (four-legged animals), including dinosaurs, are easier to recognise than those of snakes. Another reason could be that snakes tend to avoid sandy or muddy areas in which their trails could be registered, preferring vegetated terrain. Maybe, as the weight of the snake is distributed over its entire length, the trails are shallow and are not easy to identify.

Or perhaps researchers are not adequately familiar with the types of traces that snakes can create.

We are part of an ichnological team – experts in identifying fossil tracks and traces. In a recently published article in the journal Ichnos, we described the first snake trace in the fossil record, which we found on South Africa’s Cape south coast. It dates to the Pleistocene epoch, and our studies have shown that it was probably made between 93,000 and 83,000 years ago, almost certainly by a puff adder (Bitis arietans).

As this is a world first, our research team was obliged to create a new ichnogenus and ichnospecies, Anguinichnus linearis, to describe the distinctive pattern in the sand registered by the puff adder.

A snake and a buffalo
The puff adder is a not uncommon sight on the Cape south coast today and, with good reason, strikes fear into residents and visitors: its cytotoxic (tissue-destroying) venom can cause the loss of a limb or worse. It habitually suns itself on trails, staying motionless, and then strikes without warning.

We found the trace fossil in the Walker Bay Nature Reserve (adjacent to Grootbos Private Nature Reserve), just over 100 kilometres south-east of Cape Town.

Intriguingly, a long-horned buffalo – an extinct species – had walked across the same dune surface soon after the snake left its trace. We know this because one of the buffalo’s tracks is superimposed on the puff adder trace, slightly deforming it.

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A large, smooth, light grey rock surface on which the indent of a slithering snake is visible, as are several hoof prints
The puff adder trail, crossed by a long-horned buffalo trackway. Geological hammer for scale. Hayley Cawthra

The puff adder and long-horned buffalo traces were found on the surface of a loose slab, 3 metres long and 2.6 metres wide, which had become dislodged and fallen down onto the beach from overlying cliffs. The slab is submerged twice a day by high tides. We were fortunate to discover it when its surface was bare, as repeat visits have shown that it is often covered in algae or by a thick layer of beach sand.

Snakes in motion
Snakes use four main types of locomotion. Each results in distinctive, recognisable traces.

https://youtu.be/7-AKPFiIEEw?si=bUVnqFvb0yWlxcEc
Here’s how snakes move through the world.

Puff adders are heavy, thick-set snakes with an average adult length of less than a metre. They mostly employ rectilinear motion, leaving a linear, sometimes slightly undulating trace, often with a central drag mark registered by the tail tip. In this form of motion the snake uses its weight and its belly muscles and grips rough areas on the surface with the posterior edges of its scales. It is drawn forwards through the muscular contractions, creating a linear trace.

https://youtu.be/iWZfIzIayDk

We also found possible trace evidence at other sites on the Cape south coast of sidewinding and undulatory motion, but this was inconclusive. We will be looking for further, more conclusive evidence.

Filling important gaps
The newly described puff adder traces help fill a gap in the Pleistocene trace fossil record from the region. More than 350 vertebrate tracksites have been identified, of mammals, birds and reptiles. Most of these sites were registered on dune surfaces, which have now become cemented into aeolianites and re-exposed. Our latest find is yet another global first for the Cape south coast.

With other vertebrate groups, such as dinosaurs and crocodiles, the trace fossil record has substantially augmented the body fossil record, providing new insights. Hopefully this discovery will act as a spur to identify other snake traces from around the world from older deposits, and thus increase our understanding of the evolution of snakes and help to fill a substantial gap in the global trace fossil record.

Fascinating!

I am still collecting fossils.
Should post something here.......

Difficult to imagine