By Francis H. Edmunds, M.A. F.G.S.

Quarterly Journal of the Geological Society 1950

[133] The age of the Piltdown skull has long been a subject of intermittent controversy and it is a question which can only be determined from palaeontological data or other evidence inherent in the fossil itself, such as that provided by fluorine fixation; details of river-terrace forms and levels as related to the present-day thalweg of the River Ouse, and of materials comprising the gravel in which the skull was found, offer little assistance.

In the literature on the subject some misunderstanding has arisen as to the height of the gravel deposit in which the skull was found relative to the present-day River Ouse; height above the river having to some extent been used to date the fossil.

According to levels taken from the six-inch scale Ordnance Survey Map, Sussex 40 NE., the 100-foot contour above Ordnance Datum cuts the surface of the gravel spread, the highest part of which lies about 103 feet O.D. while the lowest part is about 97 feet O.D. The nearest part of the River Ouse, at Gold Bridge, is between 45 and 50 feet O.D. Thus the terrace is about 50-55 feet above the nearest part of the river.

[134] Dawson (1913, p. 119), however, stated that the terrace lies on a plateau above the 100-foot contour, with an average height of about 120 feet above O.D.; a statement true of the plateau, but not of the gravel terrace, which is the thing that matters. Again, he gave the height of the gravel spread above the main stream of the River Ouse as about 80 feet, but without stating the point of the river from which his measurement was estimated: as stated above, the spread is about 50-55 feet above the nearest part of the river.

Sollas (1924, p. 192) followed Dawson and took the height above present river-level as being 80 feet, which he converted to 25 metres, and then equated the Piltdown terrace with the 30-metre terrace, thence drawing the deduction that the gravels are probably of Chellean age. Thus was a 50-foot terrace elevated to a 30-metres, or 100-foot, terrace. These levels are repeated in H. J. Osborne White (1926, p. 63) in the Geological Survey memoir on the Lewes district, although in the same memoir fig. 10 (by H. H. Edmunds) shows the terrace at the correct altitude. This diagram indicates the general relationships of the Piltdown terrace of the River Ouse: to place in the older Pleistocene a terrace at this level in south-eastern England would involve great difficulties.

Dr. A. T. Hopwood (1935, p. 47), referring to the vertebrate fossils recorded from Piltdown, placed them in two groups: a derived group (Villafranchian) with Pliocene affinities in which he included the Piltdown skull, and a group contemporary with the gravel deposit. That may well be the position, but no deposits are known in the Weald today from which bones of land animals referable to Villafranchian species could have originated. The only Pliocene deposits of the area are marine, lying above the 500-foot contour, and these may even be Miocene.

On balance, although no actual bone-bearing deposits of early Pleistocene or late Pliocene age are known, there is nothing inherently improbable in the idea that some of the vertebrate remains come from a local late Pliocene deposit, not necessarily from a level greatly above that of the present terrace. While this seems a possible explanation, it is purely an hypothesis erected as a method of explaining the presence of the early fossils, which have been dated on strictly palaeontological grounds, in a deposit which from the evidence of river-terrace morphology is of much later age.

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Dawson, C. 19l3. On the discovery of a Palaeolithic human skull and mandible in a flint-bearing gravel overlying the Wealden (Hastings Beds) at Piltdown, Fletching, Sussex. Q. J. G. S. lxix,

p. 117.

Hopwood, A. T. 1935. Fossil elephants and Man. Proc. Geol. Assoc. xlvi, p. 46

Sollas, W. J. 1924. Ancient Hunters, Third edition. London.

White, H. J. O. 1926. The geology of the country around Lewes. Mem. Geol. Surv. [Includes as fig 10 a diagram by F. H. Edmunds.]