Modern view of Karoo fossils

0
50
THANKS DOCTOR: Probus president, Doug Sutherland, left, presented a small token of appreciation following Dr Billy de Klerk’s excellent talk on fossils and early life in southern Africa at the club meeting on Tuesday, held at the Port Alfred Ski-boat Club Picture: ROB KNOWLES

The Port Alfred Ski-boat Club meeting room was filled to capacity on Tuesday to hear Dr Billy de Klerk’s talk entitled Ancient Karoo fossils in a modern world.

De Klerk holds a PhD in palaeontology from Rhodes University, and lists among his many degrees and achievements that he is currently enjoying retirement and also turns a mean piece of wood in his garage. With relatives living in the area he regards Port Alfred as a second home, he told the audience.

A renowned palaeontologist, De Klerk has spent many years hunting for fossils in the Karoo and has an intimate knowledge of the area. He began by explaining that the Karoo itself was an excellent area to hunt for fossils due to its unique nature, and that it had remained in virtual pristine condition, aside from water erosion that formed a pyramid-shape, with older rock formations at its base and newer strata at the apex in what is termed the Karoo Basin.

“The Karoo Basin was formed between 300 and 190 million years ago,” said De Klerk.

He and his teams have extensively searched the area to determine the types of animals that lived there when the continents of South America, Africa, Antarctica, the Indian subcontinent and even Australia, were all part of a single landmass; a supercontinent named Gondwana, which began to break apart about 180 million years ago.

At this time, and until just 40 million years ago, the Earth’s northern hemisphere was ice-free and had thick vegetation, with no north polar ice-cap, but the southern hemisphere was covered in glaciers, said De Klerk. The average temperature on the planet was 12oc. Due to climatic changes caused by volcanos and extraterrestrial impacts, the average temperature rose by a massive 32oC for a period.

“We talk about global warming today, but this was like nothing we have ever experienced,” said De Klerk.

From his manner and tone it was clear that De Klerk has a vast knowledge of the subject. He further spoke of continental drift and the similarity of flora and fauna across the wide band of the southern hemisphere, which is now separated by vast oceans, but was all in the same physical location when Gondwana existed.

De Klerk brought with him a collection of fossils from the Karoo but specifically spoke of the modern methods of determining the types of animals and plants that existed in the area over the past 300 million years.

Asked how he determined the age of fossils he explained that, by observing the amount of decay of certain atoms of minerals it was now possible to give very accurate dates as to when certain events occurred.

The earliest creatures that walked the Karoo Basin were related to turtles, then small shrew-like mammals and, later, true dinosaurs and, eventually birds.

The talk included a slideshow where images of many of the animals De Klerk was speaking of were shown.

“It is possible to now use the European Synchrotron Radiation Facility in Grenoble, France, to look inside rocks to determine the type of animals fossilised in them,” said De Klerk. “We can then capture a 3D image and print out a plastic copy of the fossil in incredible detail, without having to break the rock apart.”

De Klerk showed that the ability to determine our history is now possible through the use of hi-tech equipment in a way that was not available to us in the past.

Leave a Reply