1067 REPTILE TO MAMMAL
Julien Benoit, senior researcher, Evolutionary Studies Institute, University of the Witwatersrand
The complete transition from primitive reptilian-looking animals to modern mammals can be traced in the South African fossil record. Every feature that defines mammals had its origins in the very ancient group therapsida: mammal-like reptiles.
X-ray scanning imagery has shed new light on the origin of soft tissue structures and the biology of our remote ancestors. Soft tissue anatomy such as the nervous system, brain, whiskers, venomous and mammary glands and physiology were previously difficult to reconstruct because they do not readily fossilise. The first lecture will discuss how new imaging techniques have revealed the likely origin of whiskers, mammary glands and warm-bloodedness. The next lecture will look at the evolution of the unique morphology of the mammalian brain. Implications for the origin of endothermy and the palaeo-biology and behaviour of therapsida and early mammals will be discussed. Finally, the biology of the South African therapsid, Euchambersia, the oldest venomous species, will be examined.
1. The origins of ‘mammalness’ in mammal-like reptiles
2. Origin and evolution of the mammalian brain
3. The oldest venomous species
Kemp, T.S. 2005. The origin and evolution of mammals. Oxford: Oxford University Press.