Gibraltar Neanderthals and results of recent excavations in Gorham's, Vanguard and Ibex caves

Antiquity, March, 1999 by R.N.E. Barton, A.P. Currant, Y. Fernandez-Jalvo, J.C. Finlayson, P. Goldberg, R. Macphail, P.B. Pettitt, C.B. Stringer

Introduction and background

Last year marked the 150th anniversary of the accidental discovery of the 'Gibraltar skull' [ILLUSTRATION FOR FIGURE 1 OMITTED], blasted out during work at Forbes' Quarry, below the North Face of the Rock (Busk 1865). The find, which probably came from a limestone breccia (Busk 1865) was presented on 3 March 1848 to the Gibraltar Scientific Society by its secretary, Lieutenant Edmund Flint of the Royal Artillery. The discovery very nearly placed Gibraltar at the forefront of 19th-century early human studies. But for a quirk of fate, which left the significance of the cranium undisclosed for a further 16 years, the find might have led to a very different naming of one of the earliest Neanderthal skeletal remains known to science.

In 1864, the cranium was sent to England where it was exhibited by George Busk in September at the British Association for the Advancement of Science meeting in Bath. At the meeting, the eminent scientist, Hugh Falconer recognized the fossil as 'a very low type of humanity - very low and savage, and of extreme antiquity'. He suggested that it be made the type of a new human species Homo var. calpicus, named after Mons Calpe (Gibraltar). But the specimen and the proposal were eclipsed by the publication in the same year of the species name Homo neanderthalensis, by William King, based on the Neander Valley (Feldhofer) skeleton from Germany, which had been found in 1856. Unfortunately, even today, the exact provenance of the Gibraltar skull is uncertain, and without a context it will require coupled ESR/Uranium Series dating on a tooth-enamel fragment, or direct gamma-ray dating, to estimate its real age. Nevertheless, it remains one of the best-preserved Neanderthal crania yet found, and as it probably represents a female individual, it provides valuable data on Neanderthal skeletal variation.

A second significant Neanderthal find was made in Gibraltar in 1926, at the Devil's Tower site, surrounding a cleft in the North Face limestone, not far east of Forbes' Quarry (Garrod et al. 1928). This find was excavated systematically, and had associated animal bones, Mousterian artefacts and charcoal. At present, new dating work is in progress on some of these materials. The fossil remains consist of parts of the upper and lower jaws and braincase of a Neanderthal child. The original assumption that they represented a single child about five years old at death was challenged in 1982 by Ann-Marie Tillier, who proposed that these bones might instead derive from two children, one aged about three years at death (the temporal bone) and the other about five (the rest of the bones). However, subsequent studies using incremental lines on the teeth and comparisons with recent individuals of known age at death reaffirmed the unity of the cranial material, but suggested that the child might have been about four years old at death (Stringer et al. 1990). Most recently, the Gibraltar Neanderthals have been the subject of several computerized tomographic (CT) studies (Zollikofer et al. 1995) [ILLUSTRATION FOR FIGURE 2 OMITTED], and the distinctive form of the inner ear now known for Neanderthals was first recognized in these specimens. Such studies have shown that marked quantitative differences in skull morphology can be demonstrated between Neanderthals and modern humans at an early stage in their development, further strengthening the interpretation of their existence as a separate species. Moreover, in July 1997, scientists working in Germany and the United States announced they had recovered mitochondrial DNA from the type specimen of the Neanderthal species, the Neander Valley specimen found in 1856 (Krings et al. 1997). Its DNA pattern was quite distinct from those of all recent humans so far sampled, indicating that the Neanderthal lineage probably began to split from ours about 600,000 years ago.

While the sites of Forbes' Quarry and Devil's Tower [ILLUSTRATION FOR FIGURE 3 OMITTED] are, respectively, unpromising and probably too dangerous for further excavation, there are several other sites on the Rock preserving evidence of Neanderthal activities. One, Ibex Cave, lies high up on the eastern face of the Rock, while four others lie to the southeast, close to the sea near 'Governor's Beach' [ILLUSTRATION FOR FIGURE 3 OMITTED]. The present beach mainly consists of fine limestone blast debris from military tunnelling operations, but there are also cemented remnants of more ancient beaches which presumably accumulated during Oxygen Isotope Stage 5. The caves are named (from the south) Bennett's, Gorham's, Vanguard and Boat Hoist [ILLUSTRATION FOR FIGURE 4 OMITTED]. Three of these caves (Ibex, Gorham's and Vanguard) have been excavated since 1994 as part of the Gibraltar Caves Project; some of the initial results of this work are presented below. Further details will appear in the proceedings of the Gibraltar conference held in August to celebrate the 150th anniversary of the finding of the Forbes' Quarry skull (Stringer et al. in preparation).