FIRST FOSSIL RECORD OF THE SPITTING ELAPIDAE IN THE CRADLE OF HUMANKIND, SOUTH AFRICA

摘要

There are about 151 snake species in southern Africa, but little is known about their diversity and evolution during the past 23 million years. Snakes are poorly represented, even in the richly fossiliferous Plio-Pleistocene deposits in the Cradle of Humankind. This is especially true for the venomous snakes of the family Elapidae which comprises the cobras, rinkhals, mambas, and African garter snakes. The Locus X Cave in the Bolt's Farm Cave System in the Sterkfontein Valley yielded part of a snake maxilla carrying a complete fang, which was extracted from the cemented matrix (breccia) mainly by acid preparation in the Plio-Pleistocene Palaeontology section of the Ditsong National Museum of Natural History (DNMNH). The present study shows that this fossil belongs to a spitting snake in the family Elapidae. It is not possible at present to suggest a specific species as only fragmentary maxilla remains were discovered and there are no vertebrae associated with it. That noted, the fragmentary maxilla could either belong to rinkhals represented in southern Africa today by an endemic species Hemachatus haemachatus, or to Afronaja species. Unlike in southern Africa, a well-established methodology for comparing fossil and extant osteological material of snakes in palaeontology as well as in archaeology exists in Europe. Through analysing the snake maxilla from Locus X Cave in the Bolt's Farm Cave System, this article presents a preliminary methodology to develop an approach that can be used for palaeo-herpetology and herpetology in general. This will assist in studying more of the herpetological remains from hominid-bearing sites, and give us an understanding of the palaeo-environments of these sites.