By Dr Martin Briggs
Namibia is blessed with its own important fossil site – Mesosaurus Camp. It is situated on the farm Spitzkop, owned by Giel Steenkamp. The M29 takes one east of Keetmanshoop and then onto the C17 to an area where the kopjes are covered in Quiver Trees (Aloe dichotoma), about 40 km outside of Keetmanshoop.
We were fortunate enough to arrive on a day that Giel was taking a group to view the fossils. The first stop of interest on Giel’s tour was the grave of a German colonist. The headstone reads “Hier ruft Untffz J Splittgerber geb. 2.11.77 Fretenw gef. 13.11.04 b. Spitzkoppe”, and the grave is at the spot where Johan Splittgerber lost his life to the Nama during skirmishes. Fortuitously, the grave of Untffz Splittgerber lies close to some of the most important fossils on the farm. Giel stumbled on these fossils and thought the imprints embedded in the rocks were those of the salamander, however, it took a university professor to ascertain that the fossils on Spitzkop Farm predated the salamander and he correctly identified them as members of the order Mesosauria. This area was covered in water thousands of years ago, with swamps populated by reptiles, fish, and crustaceans. They lived in water during the late Carboniferous and early Permian Eras. Mesosaurus, an amphibian reptile, living here about 270 million years ago, was the apex predator of its time. It is probably one of the most convincing examples to prove continental drift, since the same genus has been found in South America. The teeth of Mesosaurus were too soft to attack larger prey, and were predominantly filter feeders (eg plankton). As the waters receded, these inhabitants sank into the mud to be preserved as fossils. Sediment blown into the lake also covered the remnants.
Lifting a protective sheet of corrugated iron roofing, Giel pointed out the grooves of a fossil embedded in the Dwyker shale. The spine and limbs of an ancient Mesosaurus was revealed. So detailed was the imprint, that indentations indicating the dorsal spinous processes were clearly visible, and even a fracture suffered by the specimen in a toe could be determined in the smooth shale surface. We learned that the fossils on Giel’s farm are considered the oldest reptilian fossils in Southern Africa.
Giel, joking that he himself was another fossil on the farm, spritely opened and closed gates as he lead our convoy on towards a kopje where Quiver Trees grew in abundance. The stem of Aloe dichotoma, the Quiver tree, a living fossil, consists mainly of fibre, proficient at storing water. Giel enlightened us as to the origin of the name, and showed us how the Bushmen made quivers for their arrows by removing the fibrous innards of a branch. Closing one end of this ‘tube’ with a pelt resulted in a perfectly hollowed receptacle, or quiver. Small flowers appear in May, June and July in a canopy of Quiver tree leaves. He explained that, as one would expect, the leaves of this aloe are bitter and kudu will occasionally reach up to feed on this canopy. This is possibly because of anti-parasitical properties of the sap, since early stockmen added these leaves to livestock water troughs, maintaining that parasites such as ticks, would be suitably dislodged.
The forest of Quiver Trees grew amongst stacked dolorite boulders, and Giel explained that the dark coloration was magnesium oxide, while iron oxide formed the lighter colours. Locally, these pigmentations are known as ‘desert varnish’. It was here that Giel produced his trump card. He is well-known for his talent at eliciting musical notes from these rocks. The quiver trees stood to attention all around us, their stems matching the golden rays of the setting sun.
Mesosaurus Camp can be contacted as follows:
Tel: +264 (0)63 683641 Fax: +264 (0)88 650 9622 Email: firstname.lastname@example.org