Early Life on Earth
The Palaeontology Hall depicts the evolution of life on Earth, beginning at about 4000 million years ago. The entrance display includes information about the earliest environmental conditions and suggestions on how life first began on Earth. Fossils of the earliest bacteria, algal mats called stromatolites and the first multicellular organisms are displayed.
The Cambrian Period represents the first appearance of the vertebrates (animals with backbones); a very important time in evolutionary history. The first vertebrates evolved about 520 million years ago and a display provides examples of various invertebrates, the first vertebrates, which were the earliest fishes, and explains the evolution of jaws, a major evolutionary development, which allowed effective, active predation to develop. The lobe-finned fish Eusthenopteron and one of the first amphibians, represented by Ichthyostega, illustrate the transition from water to land. The emergence of fish onto land was another major transition in evolutionary history. The first amphibians are thought to have evolved from an extinct group of lobe-finned fish, which then went on to evolve into the first reptiles.
Exhibit for the Disabled
A palaeontology exhibit for the disabled includes a “touch and feel” display and associated information provided in Braille. Various fossils representing an important time in evolutionary history, namely the end-Permian extinction event are available for handling. The aim of this exhibit is to encourage blind members of the community to better appreciate our natural heritage by learning and coming into contact with fossils, something which the usual palaeontology displays do not allow, as touching display material is usually forbidden.
The Karoo Reptile display is the main display in the Palaeontology Hall and includes several remarkable fossil skeletons of Permo-Triassic vertebrates from the South African Karoo Basin. These fossils highlight the diversity of a particularly important group of animals called the therapsids, which are the ancient ancestors of mammals. One can observe how these animals gradually change through time to become increasingly similar to mammals. The latest therapsids, the cynodonts, evolved into the first true mammals by the end of the Triassic, about 200 million years ago.
Dinosaurs and Other Reptiles
An especially impressive fossil in the Hall comprises an almost complete and fully articulated (i.e. most of the bones have been preserved in their correct anatomical positions) skeleton of an extinct archosauriform called Erythrosuchus africanus. Archosauriforms are a group of reptiles that are the ancestors of crocodiles and dinosaurs. Erythrosuchus reached a maximum length of 5 metres, looked a little like a modern crocodile and was the dominant predator in the Karoo during the Middle Triassic, about 245 million years ago. This particular specimen is about 3.5 metres long and was probably a subadult. It is the only known complete, articulated specimen of Erythrosuchus.
Dinosaur fossils, including Melanorosaurus, Euskelosaurus and Lesothosaurus are displayed opposite a beautiful complete fossil of a Jurassic ichthyosaur, an extinct species of marine reptile. The fossil of Melanorosaurus is the only known skull and skeleton of this early prosauropod dinosaur. It was discovered in 1994 by the National Museum’s Karoo Palaeontology Department near Ladybrand in the eastern Free State.