SANRAL helps tell a 360-million-year-old tale

SANRAL has played an integral part in the contribution to palaeontological knowledge and the preservation of natural heritage. 

Dr Robert Gess of the Albany Museum in Grahamstown, who is supported by the DST-NRF Centre of Excellence in Palaeosciences based at the University of the Witwatersrand, and the Millennium Trust, teamed up with Professor Per Ahlberg of Uppsala University in Sweden to describe the finds.

The South African National Roads Agency (SOC) Limited (SANRAL) continues to contribute to the body of palaeontological knowledge through their support of the discovery and preservation of the fossilised remains of life from a 360-million-year-old Eastern Cape marine ecosystem. 

SANRAL’s involvement with Late Devonian research goes back to 1999 when they assisted Dr Robert Gess to rescue 30 tons of fossiliferous shale ahead of roadworks at Waterloo Farm, 2km south of Grahamstown in the Eastern Cape. 

New fossil findings from gradual excavation of these 360-million-year-old shales belonging to the Waterloo Farm estuarine lagerstätte (exceptional fossil site) were published in Science 

Lead author, Dr Robert Gess of the Albany Museum in Grahamstown, who is supported by the DST-NRF Centre of Excellence in Palaeosciences based at the University of the Witwatersrand, and the Millennium Trust, teamed up with Professor Per Ahlberg of Uppsala University in Sweden to describe the finds. 

Highlighting Devonian Research 

Their research paper entitled, Tetrapods from the Devonian Antarctic Circle, helps to highlight the global significance of late Devonian research in the Eastern Cape. 

Gess explained: “Whereas all previously found Devonian tetrapods have come from localities that were in tropical regions during the Devonian Period, the Grahamstown specimens represent species that lived in the Antarctic Circle and thus force a major reassessment of the origin of four-legged vertebrates.” 

He added: “During the Devonian Period (360 to 420 million years ago) the ancestors of all land-living vertebrates evolved from lobe-finned fish. These creatures had traded their fins for four stubby legs but retained a tadpole like tail. About a metre long, they looked superficially like a cross between fish and alligators and lived in pools, lakes and lagoons where they probably inhabited the shallows. Shortly after the End Devonian Mass Extinction Event their descendants moved onto land and gave rise to land vertebrates – amphibians, reptiles, birds and mammals, including ourselves.”  

Thousands of unique fossils 

Rob Damhuis, geotechnologist and project manager at SANRAL Southern Region, said: “At SANRAL’s inception in 1998 it became a priority to make the N2 road between Grahamstown and the Fish River safe. Whilst surveying the geology through which the Waterloo Farm road cutting went, we were made aware that the area held elements of great importance to South Africa’s history.  

“Construction of the repairs was immediately halted and SANRAL brought in Dr Gess and his team to mine out 30 cubic metres of shale by hand. SANRAL then transported the shale to Bathurst where Dr Gess began to steadily work through it in search of fossils. 

“The results of the excavations were incredible, uncovering thousands of unique fossils which are of great international importance today. So far, the remains of an entire coastal estuarine ecosystem from 360 million years ago has been discovered.” 

A further 70 tons of shale was similarly rescued in 2008 and to further assist with the fossil finds and help to preserve the shale, SANRAL built a shed next to Dr Gess’s existing shed to store the shale blocks and protect the fossils from weather damage. 

A find he had always hoped for 

Dr Gess said he had always hoped to find remains of Devonian tetrapods at Waterloo Farm, even though the text books suggested it wasn’t at all likely.  

He said: “I read Dr Jenny Clack’s book Gaining Ground and familiarised myself with the skeletal transformations involved in the fish to tetrapod transition. I was splitting shale with my student, Chris Harris, when I found the cleithrum of Tutusius. I just knew that this was what I’d spent years looking for. I went all quiet and then abandoned what I was doing and went to fetch the literature just to double check. I’ll never forget that afternoon. 

“In South Africa we have a good evolutionary history preserved in the rocks, which now adds the emergence of animals with legs from fish, to a well-studied record of the evolution of mammals from reptile-like ancestors and development of the earliest humans. Our fossil heritage is world renowned. 

“The fact that the tetrapods were found at the Waterloo Farm site gives us a really good picture of the environmental setting in which they lived. Of all sites in the world that have tetrapod remains, Waterloo Farm has the best record of what plants and animals were around the ecosystem that the tetrapods were living in. 

“This is the only site in the world that has tetrapod remains but also has soft tissue preservation. The rock shed that SANRAL donated has almost certainly preserved more remains of the bony parts of the Devonian tetrapods, but it is possible that further excavations might also reveal evidence of the non-bony parts – which are yet unknown from anywhere.” 

A continuing relationship 

SANRAL has continued to be interested in Dr Gess’s Devonian research project and recently facilitated the discovery of further fossil sites.  

While monitoring controlled rock cutting explosions by SANRAL along the N2 between Grahamstown and the Fish River in 2016, Dr Gess and Harris discovered new Devonian river mouth sites 20 km east of Waterloo Farm.  

These sites help to fill out the picture of environments along the ancient high-latitude shoreline of Gondwana. 

“It is important that the public is aware of this collaboration and is aware of the agency’s support to preserve our natural heritage,” said Mbulelo Peterson, SANRAL Southern Region Manager. 

SANRAL’s standard management plans contain guidelines for project managers who may encounter similar cases of palaeontological heritage, especially in areas where experts believe the potential for finds is high. 

“In 2016, as part of a conservation plan for the N2 Wild Coast Road (N2WCR), we initiated our environmental management programme, which is aimed at protecting the biological diversity and natural heritage of the Eastern Cape. As part of this programme we have already conducted palaeontological training for environmental and other personnel, to sensitise them to the potential for and tell-tale signs of palaeontological finds as well as to iterate what to do if such findings should occur,” Peterson added.