Faunal remains from Hot Pot Cave, Bredasdorp

Abstract

Recent unconsolidated cave deposits can be useful in providing an understanding of how consolidated fossil cave deposits were formed and are far easier and quicker to analyse. This preliminary study describes an extensive, extremely rich bone accumulation in a horizontal cave system linked to the surface by a single verticaI shaft from the middle of a domed chamber. The cave is in Tertiary marine limestone on the southwestern Cape coast. The fauna has two chief components: a macrofauna resulting from entirely fortuitous introductions such as animals falling down the shaft; and an extensive microfauna accumulated by the barn owl, Tyto alba. Between these two groups there is a very small range of possible overlap. The macrofauna contains a mixture of wild and domestic animals, herbivores and predators with sizes ranging from hare to buffalo. The microfauna is closely packed in a black organic-rich soil of predominantly dust sized particles. A feature of this soil is the vast number of tiny terrestrial snail shells it contains. The deposit represents continuous accumulation over several hundred years at least. Seeds, pollen and carbonised wood are present in the undisturbed deposit so that sequential dating will be possible. By contrast, recognisable insect cuticle is virtually absent though dung beetles, for example, are frequently seen in surface solution cavities and must fall into the cave in fair numbers. Alignment of microfauna! longbones within the deposit is horizontal and parallel to the passage walls, so it is clear that the material was distributed by stream action. Much of the fauna has a wide geographic range, but throughout there are elements either endemic to the southern Cape or indicative of the prevailing vegetation type.