Long ago, topsoil and chalk from the ancient sea cliffs fell into a pebbly beach below, where they mixed with the bones of flatfish and conger eels feeding in the intertidal zone. The land was slowly rising and the sea level falling, and as the sea gradually retreated it left several metres’ depth of fine sand behind while a huge lagoon, surrounded by salt marshes and grasslands, formed. Sand gave way to silts, and the next metre of deposits at Boxgrove is the most critical in what it preserves. Herds of game grazed on this new coastal plain – animals such as red deer, bison, horse, and even elephant and rhinoceros, as well as the animals that preyed on them, such as lion, hyaena and wolf. And people now became part of the local landscape, living off the land and the game. They were also drawn by the presence of flint in the chalk cliffs, an excellent source of raw material from which they could produce the characteristic stone tool found at Boxgrove – the handaxe – of which over 300 examples have been excavated. Because the land surfaces at Boxgrove were repeatedly covered over by gently flowing water, sealing them with a fine silt, those ancient surfaces have been protected with only minimal disturbance. The preservation is so good that the exact spots where people crouched down to make their stone tools have been conserved, with every flake of flint they struck off lying where it fell hundreds of thousands of years ago.
Not only that, but the bones of the animals they ate were also there, surrounded by tools, and often covered in butchery marks. The handaxes, which are predominantly oval or almond-shaped, were used to fillet carcasses of giant deer, red deer, bison, horse and rhinoceros. There are very few traces of cut marks on any of the bones from smaller animals such as roe deer, suggesting that smaller carcasses were either ignored or carried elsewhere for butchery. It is clear that the humans at Boxgrove had access to complete carcasses of big game, since most parts of the animals are represented at the butchery sites, and cut marks always precede those of the teeth of scavengers such as wolf or hyaena. This evidence was revolutionary when it emerged in the 1990s because it showed that these people were much more capable at getting meat than many archaeologists had believed: either they were regularly hunting big game up to the size of rhinos, or they were getting primary access to the carcasses of already-dead animals in competition with dangerous predators up to the size of lions, an equally impressive achievement. And while secondary access for scavenging and marrow extraction was probably enough to fuel the first human expansions from Africa, primary access to carcasses that still included the intestines and offal would have provided a higher quality and variety of food.
The site is dated from its mammal remains to an interglacial in the Middle Pleistocene, and the species represented are very similar to those from Westbury, particularly allowing for the fact that as an inland cave Westbury had a different local environment from the coastal plain at Boxgrove. Large animals represented as fossils include elephant, rhino, horse, bison, boar, five species of deer, ten species of large and small carnivore, and thirty small species including bats, shrews and moles. The type of water vole found at Boxgrove is once again Arvicola terrestris cantiana, as at Westbury and the Mauer sand pit that produced the famous jawbone of Homo heidelbergensis in 1907. As with Westbury, it seems that the sequence at Boxgrove is succeeded by indications of the severe cold of that critical marker the Anglian glaciation, suggesting that Boxgrove similarly belongs to the immediately preceding interglacial of Marine Isotope Stage 13, about 500,000 years old. The cold deposits look as if they have slumped down the slopes of the old chalk cliffs in spring thaws of snow and ice, and there is an intriguing hint that people did briefly try and cling to a precarious existence as the climate rapidly deteriorated, since the slurried soils contain a few stone tools.
It was not until the end of 1993, with a major discovery, that Boxgrove really hit the headlines. After nearly ten years of work, with his excavation funds running out, the Director of the Boxgrove Project Mark Roberts gambled his remaining budget on a last throw of the dice. He paid for a mechanical excavator and one volunteer, Roger Pedersen, to work over the winter months of 1993–4 on a previously unexcavated area of the site. Pedersen spotted a large bone in one of the trenches and immediately realized it was the limb bone of a large mammal – perhaps a human. A few days later Simon Parfitt and I confirmed that it was a human shin bone (tibia), and it was nicknamed Roger in honour of its discoverer. This was followed in 1995 by the excavation of two human teeth. Probably 100,000 years older than Swanscombe, these finds represent the earliest physical evidence of humans known from the British Isles, and the site has yielded a wealth of data on the behaviour of these people. We allocated the Boxgrove tibia to the same species – Homo heidelbergensis– as the Mauer jaw, and it is one of the most massive human leg bones ever found.
The individual concerned must have been about 1.8metres (5ft 11 in) tall, and the great thickness of bone in the walls of the tibia suggests that this person (presumably a man, because of the size of the bone) was heavy and muscular, probably over 90 kilograms (200lb) in weight. The strength of the bone certainly reflects the physically demanding life-style that these people had to endure, but our microscopic study of its structure suggests that the individual had reached a good age at death – perhaps forty years old. There is no evidence on the bone to suggest the cause of death, although marks show that it was gnawed, probably by wolves.
The two human teeth found at Boxgrove are from the front of a lower jaw, and are not so exceptional in size, although heavily worn. Under a microscope, they reveal a mass of scratches and pits on their front surfaces. Many of these must have been made as the individual concerned sliced with stone tools through meat or vegetable materials clenched in their jaws. The direction of the slices can even be determined, and indicates that the tools concerned were being held in the right hand. The bases of the teeth are covered in tartar deposits, and these extend down the roots at the front, meaning that they must have been partly exposed during life, and that the teeth were probably being forced back and forth during chewing or clenching the jaws. The teeth probably fell out as the jawbone lay in the ground, and there is every chance that a British equivalent of the Mauer mandible still lies waiting to be discovered in the unexcavated remainder of the Boxgrove sediments.
The sheer antiquity of the Boxgrove human bones, at half a million years, is simply staggering, and caused a sensation in the media in 1994. One of the nicest illustrations of the time scale involved (and also of the chances of winning the National Lottery in Britain) came from a story and cartoon in the London Evening Standard. The cartoon showed Boxgrove Man in a block of ice, clutching a lottery ticket. The accompanying article made the point that if Boxgrove Man had been able to buy a ticket every week for the last 500,000 years he would be about due for a big win anytime now! While the odds of finding further human fossils at Boxgrove are certainly much better than that, what of finding even earlier human fossils at sites like Pakefield, or from the time period between? Because they were able to trace fossiliferous beds over a large horizontal surface area at Boxgrove, the excavators increased their chances of finding important material, as well as revealing the associations between finds such as handaxes and animal bones on which butchery was carried out. By contrast, the deposits at Pakefield are at the bottom of a sea cliff, so it’s impossible (or too dangerous) to excavate a wide exposure there. Somewhere like Norton Subcourse (in an inland quarry), or Happisburgh (on the beach), is much more promising in terms of the potential scale of excavation. But in one case, practical limits are set by the extent of quarrying, and in the other, by the fact that the deposits are under the sea most of the time. However, AHOB workers and their colleagues are constantly monitoring sites, and with the acceleration of erosion by sea and storms in parts of East Anglia, new exposures are appearing all the time. Maybe one day we will even have sites with human fossils to rival those from Gran Dolina and Ceprano.
It is now time to move on again, to 400,000 years ago, after the destructive forces of the Anglian ic
e advance had wiped out the descendants of the Boxgrove people, and forced the River Thames southwards to its present course, at Swanscombe in Kent.
CHAPTER THREE
The Great Interglacial
For about a hundred millennia after the hunters quit Boxgrove, glacial Britain remained uninhabited. Northern Europe was similarly desolate, but further south at caves like Arago in southern France, and further east around the warm springs of Vértesszöllös in Hungary, humans survived. Then people returned, flourishing across southern Britain in a warm interglacial period. They were butchering their prey at Swanscombe in Kent, making wooden spears at Clacton-on-Sea in Essex, and building fires in woodland in what is now Suffolk. This long warm stage is known as the Hoxnian in Britain, but given the wealth of evidence of human occupation it perhaps still deserves its old name of the Great Interglacial.
In the Introduction, we saw how the stages of the Palaeolithic (Lower, Middle and Upper) were established. From the late nineteenth century onwards, archaeologists in Britain readily applied this system to sites that were already known when the terms were invented. Frere’s handaxes were Lower Palaeolithic, much of the material that MacEnery and later Pengelly excavated from Kent’s Cavern was Middle Palaeolithic, while Buckland’s discovery at Paviland Cave was Upper Palaeolithic. As we have also seen, British geologists searched for the local equivalents of Penck and Bruckner’s four glacial stages and three intervening interglacial stages. Gradually a classification was developed that partially, at least, matched the Alpine sequence. In Britain three separate glaciations could be recognized in the Pleistocene by the characteristic deposits they had left behind, and three alternating warm stages could be recognized from their characteristic plants and animals. The oldest were identified in East Anglia where warm-climate animals were fossilized under cliffs of glacial debris on the Norfolk and Suffolk coasts. The early warm stage was called the Cromerian, after the town of Cromer, and the succeeding cold stage the Anglian, after the regional name derived from the local Anglo-Saxon tribe, the Angli. The succeeding interglacial stage – the Hoxnian – was taken from John Frere’s site of Hoxne where the pollen of warm climate plants was preserved in lake deposits, and the next cold stage was the Wolstonian, named after a Midlands locality containing cold stage deposits. The final two stages were the Ipswichian, named from a site in Ipswich where warm-climate pollen was preserved, and the Devensian, named after an ancient British tribe who lived in the vicinity of the type locality of cold deposits at Four Ashes in Staffordshire. It was thought that the evidence of the oldest Alpine glaciation – the Gunz – was either missing or not yet recognized in Britain, but the Anglian was probably the equivalent of the Mindel, the Wolstonian of the Riss, and the Devensian of the Würm. The Great Interglacial was the Mindel-Riss warm stage in the Alps, and the supposedly equivalent Hoxnian interglacial in Britain was when the handaxe makers seemed to reach their acme in skill and profusion. It was also the time period that at last delivered, in Kent, the long-sought remains of a really ancient Briton, at Swanscombe.
I explained in the last chapter how the Thames was pushed south by the Anglian ice advance, leaving behind abandoned valleys and gravel deposits. The river now formed a new series of deposits creating a staircase of terraces rising up on either side of its new route, and much of London and its eastern and western suburbs are built on these platforms. As we go up the staircase, we move back in time, and the highest of the steps is about 100 foot (30 metres) above present mean sea level. This highest step corresponds to the period immediately following the 450,000-year diversion, and it first contains glacial outwash from the Anglian ice cap, and then the deposits of the following interglacial, which we know in Britain as the Hoxnian. At that time the lower reaches of the ancient River Thames were several miles wide and it ran south of its present course at Dartford in Kent, laying down thick deposits that ranged from mud to sand to coarse stony gravels. These sediments were economically important in the nineteenth century and were quarried on an increasingly vast scale near the village of Swanscombe. The Swanscombe Cement Works was the first to perfect the production of Portland cement, and became its largest supplier, exporting the material right across the Empire. The quarrymen regularly came across bones of exotic animals such as elephant, rhinoceros and giant ox, and stone tools like those found by John Frere a century earlier at Hoxne – beautiful handaxes made from shiny brown flint. Harry Lewis, a Camberwell shoemaker, collected some of the first Swanscombe pieces and Victorian antiquarians started collecting material on a large scale from the 1870s; some estimates put the total number of handaxes found in the Swanscombe area at over 100,000. But in 1935 a find was made in one of the quarries, Barnfield Pit, that would elevate Swanscombe to fame as not only one of the richest of British Palaeolithic sites but also (as Piltdown lost credibility) the true home of the oldest English man (or English woman).
A dentist called Alvin Marston first collected stone tools and fossils at Swanscombe in 1933, and on the afternoon of Saturday 29 June 1935 he was alone in Barnfield Pit, apart from a few engineers overhauling the crushing plant. ‘I noticed what appeared to be a piece of bone showing in the face about 6 foot above the floor… The object was cleared with the finger and then seen to be a human occipital bone.’ Marston had to decide whether to collect it or leave it where it was, but as he did not have a camera with him he realized he would need an eyewitness of the bone’s position in the ancient sediments. He was fortunate to find Frank Austen, the pit engineer, still working on the crushing plant and, having sketched and measured the position of the bone, he took it ‘to the nearest chemist, Mr S. Ackers, of Milton Street, Swanscombe, to be packed in cotton-wool’. Marston visited the site every weekend for the next nine months to continue searching the gravels, often sleeping there in a wooden hut with his teenage son John. ‘The left parietal bone came to light on Sunday, 15 March, 1936. My boy and I were working. We had encountered a pocket of bones, including a rhinoceros tooth, earlier in the day, but in the late afternoon I began to uncover the parietal bone. There could be no doubt about it.’ This time Marston left his son to guard the find and hurried off to ask Mr Ackers to photograph it in situ. Despite further careful searching over the next three years no more human fossils were found, and by the time World War II had broken out gravel extraction had stopped and the quarry face had slumped and was grown over with vegetation. Apparently, further gravel was removed without supervision in 1944 to help construct Mulberry harbours for the D-Day landings.
In the 1950s, another father and son team (B. and J. Wymer) were involved in locating and excavating the only surviving seam of the gravels that had contained the first two skull bones, as John Wymer explained:
Work commenced on Friday, 29 July, 1955, with the assistance of Mr A. Gibson and my parents. It was while clearing this trial section, that, on the next day a human right parietal bone was found… [it] lay dome upwards in the sandy gravel… with a slight graze caused by the spade… The bone was covered by an improvised shelter of tins and Mr A. T. Marston was contacted.
Unfortunately the bone had the consistency of wet soap, and when they tried lifting it using plaster, it broke into nine pieces, which were individually wrapped in wet tissue and newspaper and dispatched to join the other bones at the British Museum (Natural History). The Wymers continued excavating for the rest of the skull for another five years, but their search was in vain, and it may well be that it was originally there, but had been removed by quarrying before 1935, or in the wartime extraction of 1944. In which case it was powdered in concrete and may now lie on the floor of the English Channel, the eventual resting place of the Mulberry harbours.
Nevertheless, the three bones of the Swanscombe skull, scattered in the gravel 25 metres apart and found over a twenty-year period, met perfectly along the jagged sutures by which they originally knitted together in the head of their owner. Despite the fact that the bones are quite thick, to judge from the slight muscle markings this was probably a youn
g woman, with a modern-sized brain close to 1300 ml in volume. The inside surfaces of the skull are so well preserved that they show the impressions of the blood vessels around the brain and even the foldings of the brain surface, making the specimen one of the most informative fossils in this respect, and suggesting that the structure of the brain, as far as can be judged from its outside appearance, was fundamentally like ours. Because the inner surfaces of the skull bones are better preserved than the weathered outer surfaces, this also suggests that the skull must have held together for some time in the river deposits before it came apart. But the fact that what was found represented only the back of the braincase meant there was a frustrating lack of the frontal bone, frustrating because the critical structure of the brow ridges, massive in Java Man and Neanderthal Man, and small or nonexistent in modern humans (and Piltdown), remained unknown.
Thus the evolutionary position of the earliest English woman was in dispute. Some scientists, such as Sir Arthur Keith and Marcellin Boule, argued that Swanscombe would have had a domed forehead and a small brow ridge, like that of modern people. To them, Swanscombe was evidence that a ‘presapiens’ line, leading directly to modern humans, and parallel to the more primitive branch of the Neanderthals, existed in Britain during the Great Interglacial. In 1938, to back up his theory, Keith even published an exhaustive comparison of the Piltdown skull fragments with the Swanscombe parietal bone found two years earlier. Others, such as the German scientists Franz Weidenreich and Hans Weinert, argued that the shape of Swanscombe resembled the back of a fossil skull found at Steinheim in Germany in 1933. This skull was also thought to date from the Great Interglacial and, although somewhat smaller, had a frontal bone with enormous brow ridges. If they were right, it was possible that Steinheim and Swanscombe represented ancient ancestors of both the Neanderthals and modern humans.
Homo Britannicus Page 8