A hand axe is a prehistoric stone tool with two faces that is the longest-used tool in human history. It is usually composed of flint or chert. It is characteristic of the lower Acheulean and middle Palaeolithic (Mousterian) periods. Its technical name (biface) comes from the fact that the archetypical model is a generally bifacial Lithic flake with an almond-shaped (amygdaloidal) morphology. Hand axes tend to be symmetrical along their longitudinal axis and formed by pressure or percussion. The most common hand axes have a pointed end and rounded base, which gives them their characteristic shape, and both faces have been knapped to remove the natural cortex, at least partially. Hand axes are a type of the somewhat wider biface group of two-faced tools or weapons.
Hand axes were the first prehistoric tools to be recognized as such: the first published representation of a hand axe was drawn by John Frere and appeared in a British publication in 1800. Up until that time their origins were thought to be natural or supernatural (they were called «Thunderstones» because popular tradition held that they had fallen from the sky during storms or were formed inside the earth by a lightning strike and then appeared at the surface; in fact they are still used in some rural areas as an amulet to protect against storms).
Hand axe tools were possibly used in five ways:
- 1. Butchering hunted or scavenged animals
- 2. Digging for tubers, animals, water
- 3. Chopping wood and removing tree bark
- 4. Throwing at prey
- 5. As a source for flake tools
- 1 Terminology
- 2 Raw materials
- 3 Use
- 4 Variation in form
- 5 History and distribution
- 6 Analysis
- 7 Types of hand axe
- 8 The importance of the hand axe
- 9 Image gallery
- 10 References
- 11 Bibliography
- 12 External links
Some researchers have defined four classes of hand axe:
- Class I consists of large, thick hand axes reduced from cores or thick flakes; these are referred to as blanks.
- Class II consists of thinned blanks. While form remains rough and uncertain, an effort has been made to reduce the thickness of the flake or core.
- Class III hand axe may be either preforms or crude formalized tools, such as adzes.
- Class IV includes the finer formalized tool types such as projectile points and fine bifaces.
While Class IV hand axes are referred to as "formalized tools", bifaces from any stage of a lithic reduction sequence may be used as tools. (Also, other biface typologies make five divisions rather than four).
The word «biface», was used for the first time in 1920 by the French antiquarian André Vayson de Pradenne. this term co-exists with the more popular «hand axe» («coup de poing»), which was coined by Louis Laurent Gabriel de Mortillet much earlier, The continued use of the word biface by François Bordes and Lionel Balout and their scientific authority has maintained the use of the word biface in France and Spain where it has replaced the term hand axe. Use of the expression hand axe has continued in English as the equivalent of the French biface (bifaz in Spanish), while biface is used more generally for any piece that has been carved on both sides by the removal of shallow or deep flakes. The expression faustkeil is used in German that can be literally translated as hand axe, although in a stricter sense it means «fist wedge». It is the same in Dutch where the expression used is 'vuistbijl' which literally means «fist axe» and the same occurs in other languages.
However, the general impression of these tools has been too rigid as the first definitions of hand axes were based on ideal pieces (or classic) that were of such perfect shape that they caught the attention of non-experts. Over time, a deepening knowledge of their typology has resulted in a broadening of the term’s meaning, so there is now a distinction between a biface hand axe and a bifacial lithic item. In fact, according to today's definitions a hand axe is not always a bifacial item and there are many bifacial items that are not hand axes at all. Hand axes and bifacial items are not exclusive to the Lower Palaeolithic period in the Old World, they appear throughout the world and in many different prehistorical epochs, without necessarily implying an ancient origin. In fact, lithic typology has long ceased to be a reliable chronological reference and it has been abandoned as a dating system. Examples of this include the «quasi-bifaces» that sometimes appear in strata from the Gravettian, Solutrean and Magdalenian periods in France and Spain, the crude bifacial pieces of the Lupemban culture (9000 B. C.) or the pyriform tools found near Sagua La Grande in Cuba. It appears that the findings at Sagua La Grande have been misinterpreted perhaps from a misunderstanding of the concept or due to contamination of the Spanish language by English. As explained above, the word biface refers to something different in English than biface in French or bifaz in Spanish, which could lead to many misunderstandings. Bifacially carved cutting tools, very similar to hand axes, were used to clear scrub vegetation throughout the Neolithic and Chalcolithic periods. These tools are similar to more modern adzes and were a cheaper alternative to polished axes. The modern day villages along the Sepik river in New Guinea continue to use tools that are virtually identical to hand axes to clear parts of the forest. In the opinion of Professor Luis Benito del Rey of the University of Salamanca: «The term "biface" should be reserved for items from before the Würm II-III interstadial», although he also admits that certain later objects could exceptionally be called bifaces (Benito del Rey, op. cit., 1982, page 305 and note 1).
Hand axe should also not be identified with axe, which has unfortunately been somewhat over-used in lithic typology to describe a wide variety of stone tools, particularly at a time when the true use of the items being described was not understood. In the particular case of palaeolithic hand axes the term axe is an inadequate description. Lionel Balout has stated «the term should be rejected as a erroneous interpretation of these objects that are not "axes"». Subsequent studies have supported this idea, above all those examining the signs of use, as will be seen below.
As most hand axes have a sharp border all around, there is no firm agreement about their use. The pioneers of the study of Palaeolithic tools first suggested that bifaces were used as axes or at least for use in hard physical activities. The idea soon arose that the hand axe was a multi-functional tool and not only this, in addition it was realised that the different forms and shapes of the many known examples make them in effect what is colloquially known as the Acheulean "Swiss Army knife". Each type of tool could have been used for a number of different tasks.
H.G. Wells proposed in 1899 that hand axes were used as missile weapons to hunt prey – an interpretation supported by Professor William H. Calvin of University of Washington, in Seattle who has suggested that some of the rounder examples of Acheulean hand axes were used as hunting projectiles or as «killer frisbees» meant to be thrown at a herd of animals at a water hole so as to stun one of them. This assertion was inspired by findings from the Olorgesailie archaeological site in modern Kenya. There are few indications of hand axe hafting, and some artifacts are far too large for that. However a thrown hand axe would not usually have penetrated deeply enough to cause very serious injuries. Additionally many hand axes are very small. There is very little evidence of impact damage in most handaxes.
In addition, as hand axes can be recycled, resharpened and even remade throughout their lives they could have been used for many different tasks during their working life. For this reason it is misleading to think of them simply as axes, they could have been used for digging, cutting, scraping, chopping, piercing, hammering etc. In addition, and given their mass, they may also be used as a lithic core to obtain flakes that could be used as knives or transformed for specialized uses through retouching.
Tony Baker suggested that the hand axe was not a tool, but a core from which flakes had been removed and used as tools (flake core theory). However, hand axes are often found with retouching such as sharpening or shaping, casting doubt on this idea.
Other theories suggest the shape is part tradition and partly a by-product of the way it is manufactured. Since many early hand axes appear to be made from simple rounded pebbles (from river or beach deposits), it is necessary to detach a 'starting flake', often much larger than the rest of the flakes (due to the oblique angle of a rounded pebble requiring greater force to detach it), thus creating an asymmetry in the hand axe. When the asymmetry is corrected by removing extra material from the other faces, a trend toward a more pointed (oval) form factor is achieved. (Knapping a completely circular hand axe requires considerable correction of the shape.) Studies in the 1990s at Boxgrove, in which a butcher attempted to cut up a carcass with a hand axe, revealed that the hand axe was perfect for getting at bone marrow.
Marek Kohn and Steven Mithen have independently arrived at the explanation that symmetric hand axes have been favored by sexual selection as fitness indicators. Kohn in his book As we know it wrote that the hand axe is "a highly visible indicator of fitness, and so becomes a criterion of mate choice." Evolutionary psychologist Geoffrey Miller follows on their example and has said that hand axes have characteristics which make them suitable for being subject to sexual selection forces, such as that they were made for over a million years throughout Africa, Europe and Asia, they were made in large numbers, and most were impractical for utilitarian use. He says that a single design persisting across such a span of time and space cannot be explained by cultural imitation and draws a parallel between bowerbirds' bowers (built to attract potential mates and used only during courtship) and Pleistocene hominids' hand axes. He calls hand axe building a "genetically inherited propensity to construct a certain type of object." He discards the idea that they were used as missile weapons as there were more efficient weapons at the time, such as javelins, and although he accepts that some hand axes may have been used for practical reasons, he agrees with Kohn and Mithen who have shown that many hand axes show a considerable degree of skill, design and symmetry beyond the demands for utility, some were too big (such as the hand axe found in Furze Platt, England which is over a foot long) or too small (less than two inches, therefore of little practical use), they feature symmetry far beyond practical use and show evidence for excessive attention to form and finish. Miller thinks that the most important clue is that most hand axes show no signs of use or evidence of edge wear under electron microscopes. Furthermore, hand axes can be good handicaps in Amotz Zahavi's handicap principle theory: the learning costs are high, there are risks of injury, they require physical strength, hand-eye coordination, planning, patience, pain tolerance, and resistance to infection from cuts and bruises when making or using such a hand axe.
Evidence from wear analysis
- Microwear analysis: The use-wear analysis of Palaeolithic hand axes has been carried out on findings from emblematic sites across nearly all of Western Europe. Keeley and Semenov were the pioneers of this specialized investigation. Lawrence H. Keeley has stated: «The morphology of typical hand axes suggests a greater range of potential activities than those of flakes».
However, there are a number of problems that need to be overcome in carrying out this type of analysis: the first resides in the difficulty in observing the larger pieces using a microscope, this has meant that despite the millions of known pieces, very few have been thoroughly studied. The second big question arises from the clear evidence that the same tasks were performed more effectively using utensils made from flakes, including:
This raises the question: why make hand axes, whose production is more complicated and costly, if the flakes can do the same work with the same efficiency? The answer could be that, in general, hand axes were not conceived for a particular function (excluding certain specialized types) [...], they were not made for one main task but covered a much more general purpose.—Keeley, op. cit., page: 136.
Keeley, basing his observations on various archaeological sites in England, has proposed that in base settlements were it was possible to predict future actions and where there was a greater control on routine activities, the preferred tools were racloirs, backed knives, scrapers, punches, etc. (that is, tools made from specialized flakes). However, hand axes were more suitable on expeditions and in seasonal camps, where it was more likely that unforeseen tasks would need to be carried out. Their main advantage in these situations was their all-round nature, lack of specialization and adaptability to all eventualities. A hand axe has a long blade with different curves and angles, some will be sharper and others more resistant, it will also have points, notches etc. All of this combined in one piece and, given the right circumstances, it is possible to make use of loose flakes. In the same book, Keeley states that a number of the hand axes studied were used as knives to cut meat (such as hand axes from Hoxne and Caddington. He has also identified that the point of another hand axe has been used as a drill that was turned clockwise. This hand axe came from the famous archaeological site at Clacton-on-Sea (all of these site are located in the east of England). The American Nicholas Toth reached similar conclusions for pieces from the Spanish archaeological site in Ambrona (Soria); Analysis carried out by the Spaniard Manuel Domínguez-Rodrigo and co-workers on the primitive Acheulean site in Peninj (Tanzania) on a series of tools dated as 1.5 m years old shows clear microwear produced by plant phytoliths, suggesting that the hand axes were used to work wood.
- Macroscopic traces of use: Microscopes are not the only tools that provide clues to a hand axe's use, some were used with such force that marks were left that are clearly visible. Other visible marks can be left as the scars left by retouching, on occasions it is possible to distinguish them from marks left by the initial manufacture. One of the most common cases is when a point breaks, this has been seen by various researchers on sites in Europe, Africa and Asia. One example comes from the El Basalito site in Salamanca, where excavation uncovered fragments of a hand axe with marks at the tip that appeared to be the result of the action of a wedge, which would have subjected the object to high levels of torsion that resulted in the tip being broken. A break or extreme wear will not only affect a tool’s point, it could affect any part of a hand axe. However, this type of wear was reworked by means of a secondary working as discussed above. In some cases this reconstruction is easily identifiable and was carried out using techniques such as the so-called «coup de tranchet» (trinchet blow in French), or simply with scale or scalariform retouches that alter an edge’s symmetry and line.
Variation in form
The most characteristic and common shape that a hand axe has is a pointed area at one end, cutting edges along its side and a rounded base (this includes hand axes with a lanceolate and amygdaloidal morphology as well as others from the same family). However, a hand axe is an instrument with a variety of shapes, including circular, triangular, and elliptical. They can be between 8 and 15 cm in length, although they can also be bigger or smaller.
They were typically made from a rounded stone, a block or lithic flake, using a hammerstone to remove flakes from both sides of the item. This hammerstone can be hard (made of stone) or more delicate results can be obtained using a soft version made of wood or horn). However, there are a number of differences relating to a hand axe's technological aspect. For example, uniface tools have only been worked on one side and partial bifaces retain a high proportion of the natural cortex of the tool stone, often making it easy to confuse them with chopping tools. Further, simple bifaces may have been created from a suitable tool stone but they rarely show evidence of retouching.
In summary, despite the recognition of hand axes by many typological schools and under different archaeological paradigms, and despite being easily recognisable (at least the most typical examples), it is practically impossible to easily define them as a distinct set or sub-set. Stated more formally, the idealised model combines a series of well defined properties, but none of these properties are necessary or sufficient to characterize any item as a hand axe. Only some of these attributes are necessary for a useful identification, although an object may lack others.
«The study of hand axes is made complicated because its shape is the result of a complicated chain of technical actions that are only occasionally revealed in their later stages. If this complexity of intentions during the manufacture of a hand axe is added to its variety of forms [...] we realise that the hand axe is one of the most problematical and complex objects in Prehistory»—Benito del Rey, op. cit. 1982, pages 314 and 315.
History and distribution
Some early examples of hand axes, date back to 1.6mya in the later Oldowan (Mode I), called the "developed Oldowan" by Mary Leakey, but these hand axes became more abundant in mode II Acheulean industries that appear in what is now Southern Ethiopia around 1.4 million years ago, although some of the best examples come from 1.2 million year old deposits in Olduvai Gorge. They are also known in Mousterian industries.
By 1.8 mya early man was present in Europe, as shown by the discovery of skulls and Oldowan tools from that time in Dmanisi, Georgia. Remains of their activities have also been excavated in Spain at sites in the Guadix-Baza basin and near Atapuerca. Most early European sites yield "mode 1" or Oldowan assemblages. The earliest Acheulean sites in Europe only appear around 0.5 mya. In addition, the Acheulean tradition does not seem to spread to Eastern Asia. It is notable that in Europe, and particularly in France and England, the oldest hand axes only appear after the Beestonian Glaciation-Mindel Glaciation, approximately 750,000 years ago, during the so-called Cromerian complex, although they became more widely produced during the Abbevillian tradition (Abbevillian is an obsolete name for a tradition now seen as part of the Oldowan, it is also applied to distinguish certain crudely worked bifaces).
The apogee of hand axe manufacture took place in a wide area of the Old World, especially during the Riss glaciation, in a cultural complex that can almost be described as being cosmopolitan and which is known as the Acheulean. The use of hand axes survived during the Middle Palaeolithic in a much smaller area, being especially important during the Mousterian, up to the middle of the Last glacial period.
(In Europe) «Small bifaces are found from the late Acheulean until the Aurignacian—Pierre-Jean Texier (page 18)
Hand axes dating from the lower Palaeolithic have been found on the Asian continent, on the Indian subcontinent and in the Middle East (to the south of Parallel 40° N), but they were absent from the area to the east of the 90° E meridian. In fact the American archaeologist Hallam L. Movius designated a border (the so-called Movius Line) between the cultures that used hand axes to the west and those that maintained a tradition based on chopping tools and small retouched lithic flakes, such as were made by Peking man and the Ordos culture in China, or their equivalents in Indochina such as the Hoabinhian. The Padjitanian culture from Java was traditionally thought to be the only oriental culture to manufacture hand axes. However, new archaeological evidence from Baise, China shows that there were also hand axes in eastern Asia.
In North America, hand axes make up one of the dominant tool industries, starting from the terminal Pleistocene and continuing throughout the Holocene. For example, the Folsom point and Clovis point traditions (collectively known as the fluted points) are associated with Paleo Indians, some of the first people to colonize the new world (see Models of migration to the New World). Further, hand axe technology is almost unknown in Australian prehistory.
Contemporary experiments in knapping have demonstrated the relative ease with which a hand axe can be made, which could go some way in explaining their success. In addition, as tools they are not very demanding in terms of maintenance nor in the choice of raw materials, any rock will suffice so long as it supports a conchoidal fracture. It is easy to improvise during their manufacture or correct mistakes without requiring detailed planning and above all there is no requirement for a long, demanding apprenticeship to learn the necessary techniques. All these factors combined have meant that these objects remained in use throughout pre-history. In addition, their adaptability makes them effective in an enormous variety of tasks, from the most heavy duty such as digging in soil, felling trees or breaking bones to the most delicate such as cutting ligaments, slicing meat or perforating a variety of materials.
Lastly, a hand axe represents a prototype that can be refined giving rise to more developed, specialised and sophisticated tools such as the tips of various projectiles, knives, adzes, hatchets etc.
Given the typological difficulties in determining the limits of what constitutes a hand axe, it is important when analysing them to take account of their archaeological context (geographical location, stratigraphy, the presence of other elements associated with the same level, chronology etc.). Due to their extreme age it is also necessary to study their physical state to establish any natural alterations that may have occurred: patina, shine, wear and tear, mechanical, thermal and / or physical-chemical changes such as cracking, in order to distinguish these factors from the scars left during the tool’s manufacture.
The raw material is an important factor to be taken into account, not just because of the result that can be obtained by working it, but also in order to understand the economy of prehistoric humans and their movements. In the Olduvai Gorge (Tanzania), the places where the raw materials are most readily available are some ten kilometres from the nearest settlements. However, flint or silicate is readily available on the fluvial terraces of Western Europe. This therefore means that there will be different strategies required for the procurement and use of available resources in different areas. The supply of materials was the most important factor in the manufacturing process as Palaeolithic artisans were able to adapt their methods to whatever materials were available, obtaining adequate results from even the most difficult raw materials. This has been demonstrated by many experts (Bordes, Tixier, Balout: in Benito del Rey, 1982, op. cit. pages 306-307; Hayden, Carol et al, Jeske, etc.: in Torrence, 1989 Despite this it is important to study the rock’s grain, texture, the presence of joints, veins, impurities or shatter cones etc.
In order to study the use of individual items it is necessary to look for traces of wear such as pseudo-retouches, breakage or wear, including areas that are polished. If the item is in a good condition is possible to submit it to use-wear analysis, which is discussed in more detail below. Apart from these generalities, which are common to all carved archaeological pieces, hand axes need a technical analysis of their manufacture and a morphological analysis.
The technical analysis of a hand axe tries to discover each of the phases in its chaîne opératoire (operational sequence). The chain is highly flexible as a toolmaker may focus narrowly on just one of the sequence’s links or equally on each link. The links examined in this type of study start with the extraction methods of the raw material, then include the actual manufacture of the item, its use, maintenance throughout its working life and finally its disposal.
A toolmaker may put a lot of effort into finding the highest quality raw material or the most suitable tool stone. In this way more effort is invested in obtaining a good foundation, but time is saved on shaping the stone, that is the effort is focussed on the start of the operational chain. Equally the artisan may concentrate the most effort in the manufacture so that the quality or suitability of the raw material is less important. This will minimize the initial effort but will result in a greater effort at the end of the operational chain.
Tool stone and cortex
Hand axes are most commonly made from rounded pebbles or nodules, but many are also made from a large flake. Hand axes made from flakes first appeared at the start of the Acheulean period and became more common with time. Manufacturing a hand axe from a flake is actually easier than from a pebble, it is also quicker as flakes are more likely to be closer to the desired shape. This allows easier manipulation and fewer knaps are required to finish the tool, it is also easier to obtain straight edges. When analysing a hand axe made from a flake it should be remembered that its shape was predetermined (by use of the Levallois technique or Kombewa technique or similar). Notwithstanding this it is necessary to note tools characteristics: type of flake, heel, knap direction.
Cortex: this refers to the natural external cortex or rind of the tool stone (pebble, rock, nodule, flake or slab of stone) that due to erosion and the physical-chemical alterations of weathering is different from the stone’s interior. In the case of chert, quartz or quartzite, this alteration is basically mechanical and apart from the colour and the wear it has the same characteristics as the interior in terms of (hardness, toughness etc.). However, flint is surrounded by a limestone cortex that is soft and unsuitable for the manufacture of stone tools. As hand axes are made from a tool stone’s core it is normal to indicate the thickness and position of the cortex in order to better understand the techniques that are required in their manufacture. Although it may be thought that the more cortex is present the older the item is, the variation in cortex between utensils should not be taken as an indication of the age of the item.
Many partially worked hand axes simply do not require further work in order to be effective tools, they can be considered to be simple hand axes. On the other hand, when a tool stone is less suitable it will require more thorough working. There are hand axes where the cortex is unrecognizable due to the complete working that it has undergone, which has eliminated any vestige of the original cortex.
It is possible to distinguish the following types of hand axe:
- Unifaces: is only flaked on one of its faces and the cortex completely covers the other side. This fact does not imply that these tools cannot be classified along with biface hand axes and it is also no indication of their age, the presence of uniface hand axes is not an indicator of chronology.
- Partial bifaces: The cortex is present on the base and central part of the tool. The overall area that is not knapped may extend to up to 2/3 of a tool’s length.
- Bifaces with basal cortex coverage: Only the base of the artefact is covered with cortex, which does not cover more than a third of the tool’s length. In some cases the cortex is present on both the base and on one side, thereby affecting one of the edges, these articles are called «natural backed». Gabriel de Mortillet was already emphasising the importance of the presence or absence of the cortex around the edge of a utensil in the 19th century: «Even on some of the best worked pieces it is common to see, sometimes on the base but more often on the side, a small area that has not been worked, that is uncut. It could be thought that this is a mistake or an error. But often the most possible reason for this is that it was intentional. There are a large number of hand axes with an uncut base, unworked or partially cleaned ... an area has intentionally been left on these pieces as a grip, it is called the heel. This heel acts as a handle as it is easy to grip» (this idea has not been completely discarded, but as it has not been scientifically proven it is not commonly used).
- Hand axes with residual cortex on an edge: These hand axes have the whole of their edges knapped except for a small area where the cortex remains (leaving a small area without a sharp edge). This area can be at the base, side or oblique. In all cases it must be small, leaving cutting edges on both sides.
- Hand axes with a cutting edge around the whole circumference: The whole circumference of these utensils is knapped to a cutting edge, although there may still be residual areas of cortex on either face, without them affecting the cutting edge’s effectiveness.
Older hand axes were produced by direct percussion with a stone hammer and can be distinguished by their thickness and a sinuous border. Later Mousterian hand axes were produced with a soft billet of antler or wood and are much thinner, more symmetrical and have a straight border. An experienced flintknapper needs less than 15 minutes to produce a good quality hand axe. A simple hand axe can be made from a beach pebble in less than 3 minutes.
Lithic reduction is the process by which a hand axe is manufactured. This phase is commonly thought of as being the most important in the fabrication of a hand axe, although it is not always the case, as has been discussed for hand axes made from flakes or a suitable tool stone. In studying the elaboration of a hand axe it is necessary to identify the type of implement that has been used to form the biface. If there have been a number of implements used it is essential to discover the order they were used in and the result obtained by each one. Naturally it is not always possible to discover the type of implement used, but the most common implements are:
- Hand axes formed only using a hard hammer, without subsequent reworking of the edges. A hammerstone was the most common percussive tool used during the Acheulean. The resulting artefact is usually easily recognizable as they are large and have irregular edges, as the removed flakes leave behind pronounced percussion bulbs and compression rings. The use of a hammerstone results in a small number of flakes that are wide and deep leaving long edges on the tool as their highly concave form yields curving edges. The cross-section is irregular, often sub-rhombic, while the intersection between the piece’s two faces forms an acute angle of between 60° and 90° degrees. The shape of this type of hand axe is similar to that of the core as the irregularities formed during knapping are not corrected, in fact, the notches obtained were exploited in the production sequence. It is common that this type of manufacture yields «partial bifaces» (that is with an incomplete working that has left many areas still covered with the original cortex), «unifaces» (tools that have only been worked on one face), «bifaces in the Abbevillian style» and «nucleiform bifaces». This type of manufacturing style is generally an indication of the age when a tool was made but it cannot be taken as an indicator of chronology unless a tool is accompanied by other archaeological data that provide a context and allows the age of the tool to be estimated.
- Hand axes formed with a hard hammer and with edges also modified using a hard hammer have a more balanced appearance as the modification consists of a second (or third) series of blows to make the piece more uniform and provide a better finish. The modification is often called retouching and is sometimes carried out using invasive retouching or using softer, marginal, shallow blows that are only applied to the most marked irregularities leaving scale-like marks. The modification of edges with a hard hammer was carried out from the beginning of the Acheulean and persisted into the Musterian. It is therefore not very useful as an indicator of chronology (in order for it to be considered as a marker it has to be accompanied by other complementary and independent archaeological data. The hand axes arising from this methodology have a more classical profile with either a more symmetrical «almond» or «oval» shape and with a lower proportion of the cortex of the original core. It is not always the case that the retouching had the objective of reducing an edge’s irregularities or deformities, in fact, it has been shown that in some cases the retouching was carried out to sharpen an edge that had been blunted by use or a point that had deteriorated.
- Hand axes roughed-out using a hard hammer and finished with a soft hammer: it is possible to distinguish blows that resulted in deep conchoidal fractures (resulting from the first phase of manufacture, the roughing-out) and features resulting from sharpening with a soft hammer (made from bone, horn or hard wood) leaving shallower, more distended, broader scars sometimes with small, multiple shock waves. It is often difficult to distinguish between flakes caused by the different hammers as a small hard hammer that is appropriately used can leave similar marks to a soft hammer. The hand axes obtained in this way are usually balanced, symmetrical and sometimes they are even relatively smooth. Working with a soft hammer first appeared in the Acheulean period, which means that tools with these markings can be used as a post quem estimation, but with no greater precision. The main advantage of using a soft hammer rather than a hard one is that a flintknapper is able to remove broader, thinner flakes with barely developed heels, which allows a cutting edge to be maintained or even improved for the minimal amount of raw material wastage. The downside is that a high quality raw material is required to make their use effective. There are no studies that allow comparison as to whether the use of a soft hammer increases the yield per unit weight of raw material, or regarding the difference in energy use between the two hammer types. The use of a soft hammer requires greater use of force by the flintknapper and a steeper learning curve although it offers more flakes for less raw material.
- Hand axes manufactured and retouched only using a soft hammer are much less common. In fact it is highly likely that there was some initial working with a hard hammer but subsequent flaking with a soft hammer erased all vestiges of that work. A soft hammer is not suitable for all types of percussion platform and it cannot be used on certain types of raw material, both need to be suitable for this technique. It is therefore necessary to start either working with a hard hammer or with a flake as a core as its edge will be fragile (flat, smooth pebbles are also useful). This means that although it was possible to manufacture a hand axe using a soft hammer it is reasonable to suppose that there was an initial phase to prepare a blank followed by one or more phases of retouching to finish the piece. Having said this, the degree of separation between the phases is not certain, as the work could have been carried out in one operation. Working with a soft hammer allows a knapper greater control of the knapping and also there is less waste of the raw material allowing the production of longer, sharper, more uniform edges that will increase the working life of a tool. Hand axes that have been made solely with a soft hammer are usually more symmetrical and smooth, with rectilinear edges and with shallow indentations that are broad and smooth so that it is difficult to distinguish where one flake starts and another ends. They generally have a regular biconvex cross-section and the intersection of the two faces forms an edge with an acute angle, usually of around 30°. They were worked with a great deal of skill and therefore they are usually aesthetically attractive. They are usually associated with periods of highly developed tool making such as the end of the Acheulean (e.g.: the Micoquien) or the Mousterian. However, caution must be exercised as manufacturing with a soft hammer should not be used as the sole method for dating any strata.
It should be remembered that the manufacture of hand axes was not an objective in itself, they were designed as tools and as such they wore out, deteriorated or broke during their use. Therefore, when they arrive in the hands of a Palaeolithic archaeologist or typologist they are pieces that have suffered dramatic changes throughout their useful lives. It is common to find edges that have been sharpened, points that have been reconstructed and profiles that have been deformed by reworking in order to take advantage of the piece until it was abandoned. A tool may even have been recycled later, this has led François Bordes to note that hand axes «are sometimes found in the Upper Palaeolithic. Their presence, which is quite normal in the Perigordian I, is often due, in other levels, to the collection of Mousterian or Acheulean tools.».
The detailed study of the manufacture of a subpopulation of hand axes belonging to a given lithic industry will allow a precise description to be made regarding the manufacturing process and permit statistical comparison with other groups of hand axe. This type of study is termed exploratory data analysis.
Hand axes have traditionally been oriented with their narrowest part upwards (presupposing that this would have been the most active part, which is not unreasonable given the large number of hand axes that exist with unworked bases). The axis of symmetry that divides a biface in two is called the morphological axis and the main face is usually the most regular and better worked. These are simple typological conventions that allow specialists to better understand each other. In the same way there are other terms used to describe a hand axe's morphology (or that of any other worked lithic object) that refer to purely technical concepts. It is therefore necessary to use the term base and not heel as in lithic typology the latter relates to a specific part of a flake that does not relate in any way to the base of a hand axe. It is also a mistake to use the expression distal zone to refer to the terminal zone or apex of a hand axe.
The Terminal Zone of a hand axe is, generally, the narrowest part opposite the base. Its most common shape is pointed, more or less acute or oval, some hand axes have terminal ends that are rounded or polygonal (i.e. not pointed) and lastly some hand axes have terminal ends that are transversal to the piece’s morphological axis these are cleaver or spatulate hand axes.
The Proximal End or base of a hand axe is opposite the terminal end (and is usually broader and thicker), it can be described as follows: reserved, partially or totally worked, but not cut; or cut, with a rounded (polygonal), flat or pointed end.
The Edges: In morphological terms a hand axes edge’s can be convex, rectilinear or concave, in addition they can be more or less even. There are also examples of edges that are denticulate - scalloped – or notched. It should also be noted that some hand axes have unsharpened edges. The profile of a hand axe’s worked edges can be regular without pronounced (rectilinear deviations, that is, the edge is gently curved in the form of an S) or an edge may be more sinuous and wave-formed with, on occasions, pronounced curves or deviations in the edge's profile. When describing the morphology of a hand axe it is also important to note whether the whole perimeter of the tool has been formed into a working edge of only selected areas.
The Cross section is taken across a hand axe’s central area or near to the apex. This provides an understanding of how each piece was worked, it is even possible to discern retouching or rebuilding in deteriorated parts of the edges. The following types of cross section are commonly seen: triangular (sub-triangular and backed triangular), rhombic (rhomboidal and backed rhomboidal), trapezium (trapezoid and backed trapezoidal), pentagon (pentagonal and backed pentagonal), polygonal, biconvex or lenticular (sub lenticular) etc.
The Profile: By definition, when a hand axe is seen straight on it should have a roughly balanced outline, with a morphological axis that also serves as an axis of bilateral symmetry and a plane that serves as an axis of bifacial symmetry. This does not mean that all hand axes are perfectly symmetrical. Firstly, symmetry has been achieved after millennia of technological perfecting, so it is not surprising that the oldest pieces are slightly asymmetrical. Secondly, symmetry is a typological criterion, but it does not necessarily help in the creation of more effective tools. Hand axes were used in a variety of heavy physical tasks. They deteriorated, wore out and broke and were often repaired with retouching of their edges, recovery of their points or complete reworking. Museums and private collections usually show the pieces that are aesthetically pleasing or which conform to a stereotypical model. This may be didactic, but in an archaeological excavation, the majority of the pieces that are seen by the archaeologists are remains, pieces that have been discarded after a long and complex life as tools. They will have been adapted to deal with particular circumstances or requirements that we cannot begin to imagine and the original tools have doubtless been altered. For this reason an unnatural and classical concept of symmetry is not always visible in real archaeological pieces.
Notwithstanding all this, for practical reasons the profiles' of hand axes can be classified into the following categories:
Dimensions and ratios
A hand axe’s measurements should have the morphological axis as a reference and use this for orientation. In addition to the three basic dimensions (length, width, depth), specialists have proposed a wide range of other physical quantities, with the most commonly used being those proposed by François Bordes (1961) and Lionel Balout (1967):
- Maximum length (L)
- Maximum width (m)
- Maximum depth (e)
- Distance from the base to the zone with the maximum width (a)
- Width 3/4 of the way along the piece (o)
The last two, that is a and o, represent locations that can be used to delineate the contours of the hand axe’s cross section and to measure the angles of the edges (provided this is not an area covered in the stone’s original cortex). These angular measurements for the edges are made using a goniometer.
It is also possible to take other measurements such as the length of an edge, the piece’s weight, the length of the chord described by the edges (if the piece has a transverse terminal bezel) etc. All these measurements allow a number of morphological and technical ratios to be established (for example, the relationship between the weight and the length of the cutting edges, or the relationship between the hammer used to form the piece and the angle obtained etc.).
However, the most commonly used coefficients are those established by Bordes for the morphological-mathematical classification of what he called «classic bifaces» (Balout proposed other indices but they are very similar so it is not necessary to repeat measurements):
- Base-rounding index: allows classic bifaces to be separated into three families (triangular, almond-shaped and oval): it is established using the L/a ratio that provides the following separation thresholds:
|Triangular bifaces (the most regular)
or sub triangular (for the irregular ones)
- Elongation index: which separates common bifaces from the short (and, occasionally, from the elongated). For example, within the family of Oval bifaces the index is able to distinguish between discoidal bifaces and other types; in the Almond-shaped bifaces it can be used to recognize lanceolate or micoquien bifaces. The index is calculated using L/m and the thresholds are:
- Cross sectional or planar index: which divides the thick bifaces from the flat ones and is only used on certain types. In the Almond-shaped bifaces (along with the elongation index) it distinguishes between the amygdaloidal bifaces (thick) and the cordiform bifaces (flat). The index is calculated using m/e and the thresholds are:
There are other indexes, beyond those that Bordes insists must be applied to what he called classic bifaces. These other indexes apply to the other types of bifaces (partial bifaces, bifaces with an unworked base, or cleaver, spatulate, Abbevillean, nucleiform bifaces etc.).
Types of hand axe
Hand axes are so varied that they do not actually have a single common characteristic… [...] Despite the numerous attempts to classify hand axes, some of which date to the beginning of the [20th] century… their study does not comply completely satisfactorily to any typological list—Gabriel Camps
Taking this into account, the following is to be considered a guide, based on traditional concepts, strongly influenced by the so-called «Bordes method» (a basically morphological classification system used by some schools, which is possibly now out-dated) that may be useful for general use. This classification is sufficiently trustworthy when dealing with classic hand axes, which are, precisely, those that can be defined and catalogued using a system that measures dimensions and mathematical rations, while disregarding nearly all subjective criteria. However, this supposed objectivity is merely a convention adopted by its author, based on his scientific experience and, in the majority of cases, it agrees with previously established categories (although slightly redefining them). It is also possible to find a similar attempt at categorization in Lionel Balout’s work.
They are the most common biface in this group, they are defined by their almond shape, symmetrical tendency and metric indices common to this category. Apart from their shape, which gives them their name (amygdala in Latin means almond), they are bifaces of regular length (1.3 < L/m < 1.6), somewhat thick (m/e < 2.35) and with an average base roundness index for this category (2.75 < L/a < 3.75). The base may be unworked or worked. Equally they may have a sharp-pointed or oval apical zone, however, in some cases it may be slightly rounded (and narrow)).
Amygdaloidal bifaces are nearly identical to cordiform bifaces, except that the latter are thick and the former are flat. Amygdaloidal bifaces usually have a course finishing and high-degree of cortex coverage, which is not necessarily an indication of development or chronology.
A cordiform biface is literally identical to the amygdaloidal when seen from the front as it shares the same mathematical parameters (elongation index: 1.3 < L/m < 1.6; and base roundness index: 2.75 < L/a < 3.75), but when seen from the side it is seen to be a flat biface (m/e > 2.35). Occasionally, although this does not form part of its definition, they are objects worked with greater skill, better finished, with less cortex and they are more balanced, they may also have more acute, rectilinear edges making them more efficient.
Their name, which also comes from the Latin (cor means heart), was suggested by Boucher de Perthes in 1857, but did not become generally used until it became used by Henri Breuil, Víctor Commont and Georges Goury in the 1920s.
Bordes defined them mathematically and described them as flat bifaces with rounded, short bases and a pointed or oval terminal zone. He defined eight variants, including an elongated form (L/m > 1.6) and another that is more irregular that has been called Subcordiform. The cordiform bifaces were common in both the Acheulean and the Mousterian.
Elliptical bifaces are also known as Limandes (from the French word meaning flounder). They have three axes of symmetry, bilateral, bifacial and horizontal. The latter means that if the base is short they are virtually identical at the terminal end, sometimes making it difficult to decide how to orient the piece.
In practice they are equal to the ovoid tools in all their dimensional ratios, except that the elliptical bifaces are usually more elongated (L/m > 1.6) and their maximum width (m) is nearer to their mid length.
Bordes explained that elliptical bifaces are found throughout the Acheulean and into the Mousterian, with the only difference being that the finishing became more careful and balanced over time. Bordes usually differentiated between flat elliptical bifaces (m/e > 2.35, «true Limandes») from thick elliptical bifaces (m/e < 2.35, «Protolimandes»).
Despite the attempts of many experts to develop a biface typology based on objective data, especially François Bordes and Lionel Balout who used a hand axe’s dimensions as criteria, numerous examples still escape classification apart from using systems that require either the subjective or personal judgement of the researcher or which require a lot of professional experience in order to distinguish the relevant factors. For this reason Bordes created the group called «non-classic bifaces» to which mathematic indexes cannot be applied.
- Nucleiform bifaces: It is difficult to identify this type of biface as it is difficult to determine if a piece is a true biface or simply a core with modified edges that was occasionally used as a tool. A piece could also be a blank or a chance occurrence. Despite their rough appearance nucleiform bifaces were present in both the Acheulean and the Mousterian.
- Cleaver-bifaces: These are bifaces whose apex is neither pointed nor rounded, they possess a relatively wide terminal edge that is transversal to the morphological axis. This edge is usually more or less sub-rectilinear, but also slightly concave or convex. Despite dealing with hand axes that are incompatible with mathematical indexes they are sometimes included within the classic types as they have a balanced well-finished form. Cleaver-bifaces were defined by Jean Chavaillón in 1958 under the term «Biface with terminal bevel» (biface à biseau terminal), while Bordes simply called them «cleavers» (hachereaux); the current term was proposed in French by Guichard in 1966 (biface-hachereau). The term biface-cleaver was proposed in Spanish in 1982 (bifaz-hendidor), with «biface» used as a noun referring to the typological group a piece belongs to due to its bifacial modelling and «cleaver» used as an adjective because of its morphology. That is to say, technically they are bifaces but morphologically they are similar to cleavers, although their personality is completely distinct:
Some authors count them as cleavers (F. Bordes, 1961, p 63), which J. Chavaillon does not agree with; the carving technique used to create a biface is not in any way similar to the manufacturing process for cleavers—Alimen, 1978, op. cit. page 121.
In reality the multi-use capability of a biface, including this type, conflicts with the technological simplicity of a cleaver, even though their morphology and function may be similar.
- Abbevillean style bifaces: This hand axe takes its name from the French municipality of Abbeville, where they were first found in a marl quarry in the valley of the River Somme. They were initially associated with the Abbevillean culture, for which they are an index fossil (although paradoxically these hand axes are particularly scarce at the Abbeville site). The Abbevillean was considered to be the European antecedent of the Acheulean until recently, although it has now become integrated as an initial archaic phase of the latter, even if it does not always appear in the stratigraphic register. In the same way, it has been shown that archaic hand axes such as those from Abbeville can be found throughout the Lower Palaeolithic, without this suggesting any kind of chronological or cultural reference, which is why the term Abbevillean style biface has been used. These hand axes were worked only using a hard hammer, without any retouching of the edges, leaving them extremely sinuous. They are clearly asymmetrical, varied and irregular, with their shape generally determined by that of the stone that acted as a core (this makes it impossible to find two of the same shape). Their base is covered by cortex along with large areas of the sides and they are very thick.
- Partial bifaces: These are hand axes, which have been worked in limited areas, without the knapping affecting more than a small part of the core. However, a tool with the morphology of a hand axe has been obtained with only a few blows, although this nearly always depends on the correct choice of core. They are pieces that are often barely recognizable as chopping tools, but their general aspect and finishing means they a considered as bifaces. On occasions the reason they have been considered as bifaces has been due to the extreme age of the industry to which they belong, on other occasions, they are unfinished pieces, although others show a clear economy of effort:
A knapping so incomplete, but so careful, added to the morphology of the core, allows us to talk of a finished hand axe, that was not worked more because it was not necessary, thereby saving energy.—Benito del Rey y Benito Álvarez, page 175.
Tools sometimes categorized as bifaces
Hand axes constitute an important group within the panoply of artefacts from the Lower Palaeolithic, and more particularly the Acheulean. They are particularly important in the open air archaeological sites (L. H. Keelley has suggested that they are less common in cave sites). Due to their size and technological design hand axes have often been considered to be fundamentally different from tools made from flakes (such as racloirs, scrapers and punches etc.) which has led to a distinction being made between the so-called group of flake utensils and group of core utensils. Hand axes, chopping tools and trihedral picks can be considered as core utensils, which were commonly manufactured out of stones, blocks or rock nodules. However this grouping is problematic as all these tools were often also fabricated from flakes, although obviously from large flakes. Another common suggestion is to refer to flake tools as «micro industry», as opposed to the more general size referred to as «macro industry», which includes the tools mentioned above plus the cleavers. However, this scheme also runs into problems as some scrapers are as big as hand axes, or put the other way, there are some hand axes that are as small as scrapers (and the same is true of the other types of tool mentioned). Apart from the above, associating hand axes with chopping tool and cleavers is a problem from any point of view.
- Firstly, it is true that the most elaborated chopping tools and partial hand axes are interlinked as it is often difficult to distinguish between them. But the concept of chopping tools is not only based on their lack of formal standardization (which is typical of hand axes), it also includes the possibility that the pieces are not tools, but in fact shallow cores, which is unthinkable for the bifaces (except the nucleiforms).
- In the case of choppers the inclusion is more doubtful for reasons discussed above, this is despite the fact that in his popular 1961 typology Bordes put them in the same grouping. Nobody denies that hand axes and cleavers would occasionally have served for similar tasks, but their technological design is diametrically opposed (as numerous experts have shown).
- For some time trihedral picks were considered a specialized type of hand axe. However, since they have been closely studied and classified it has become clear that they should be considered as a separate category.
Another group of tools commonly associated with hand axes is the biface leafpoint tools from the Lower Palaeolithic and above all from the Middle Palaeolithic in the Old World. The difference between the two types is based on the latter’s fine, light finishing that is carried out using a soft hammer and in a more specialized morphology that suggests a specific function, possibly as the point of a projectile or a knife. Representatives of these tools include well known examples from the classic specialized literature:
The term leaf piece should be prefixed to leaf point, as many of them are not pointed. They have been found sporadically in a number of Mousterian sites in France, but they are most common in central European Mousterian sites and African sites from the end of the Aterian—Bordes, 1961, op. cit., page 41
- The biface leafpoint tools of central Europe are called blattspitzen. They are without doubt projectile points belonging to the Middle Palaeolithic with a leaf-shaped form. They are often dual pointed and very flat, to such an extent that they are similar to Solutrean laurel leaf blades and it is only possible to distinguish the two from their archaeological context. Blattspitzen survived in some Upper Palaeolithic cultures and, as Denise de Sonneville-Bordes has pointed out, the pieces from the eastern European Szeletien culture (both blattspitzen and Micoquian bifaces) could be the link that connects the tradition of Lower and Middle Palaeolithic bifacial objects with those from the Upper Palaeolithic and beyond.
- Hand axes found in Africa come from both the Aterian culture of North Africa and the Stillbay culture from the east of the continent. Both these cases relate to Mousterian cultures, although they are relatively late and have their own style, at the end of the so-called African Middle Stone Age. In both cases a variety of objects are found, triangular, oval and other leafpoint, there are also invasive hand axes and unifaces.
The importance of the hand axe
Many people originally denied that modern day humans evolved from inferior beings. The initial finding of human fossils such as the Neanderthals or of Homo erectus (clumsily interpreted) appear to support the hypothesis that we are descended from ignorant savages that survived solely thanks to their brute force. The hand axe played a very important role in breaking this prejudice. The publications of John Frere, in Britain, and more importantly of Boucher de Perthes, in France, throughout the 19th Century described pieces that were balanced, full of symmetry and crafted with a surprising formal purity. Juan Vilanova i Piera published similar works in Spain during the 19th Century and this work was continued by José Pérez de Barradas and Casiano del Prado at the start of the 20th Century. It was therefore realised that such tools could only have been made by intelligent, even numinous minds with a certain aesthetic:
Art passed through a long formative period before becoming beautiful; but this does not mean that it ever stopped being a sincere and grandiose art, sometime more sincere and grandiose than beautiful; in mankind there is a creative nature that is manifested as soon as its existence is assured. When he was not worried or fearful, this demigod acting in tranquillity, found the material in his surroundings to breathe life into his spirit.
As André Leroi-Gourhan explained, it is important to ask what was understood of art in such distant times, above all taking into account the different psychologies of non-modern humans and ourselves. The archaeological records that he handled led Leroi-Gourhan to be surprised by the rapid progress towards symmetry and balance. He felt that he could recognize beauty in the strictest sense of the word in early prehistoric tools made during the Acheulean:
It seems difficult to admit that these beings did not experience a certain aesthetic satisfaction, they were excellent craftsmen that knew how to choose their material, repair defects, orient cracks with total precision, drawing out a form from a crude flint core that corresponded exactly to their desire. Their work was not automatic or guided by a series of actions in strict order, they were able to mobilize in each moment reflection and, of course, the pleasure of creating a beautiful object.—Leroi-Gourhan, 1977, op. cit. page 35.
However, we should not lose our perspective: many authors only refer to exceptional pieces, the majority of hand axes certainly tended to symmetry, but they do not necessarily awaken a sense of the aesthetic. In the majority of cases of we are talking about a selected series of the most striking pieces, mainly collections that were made during the 19th century or the beginning of the 20th, when a profound lack of knowledge regarding prehistoric technology prevented a clear recognition of human actions in the crudest objects. Other collections were made by aficionados, whose interests were not scientific, so that they only collected the best, those objects they considered to be the most outstanding, abandoning the humbler elements that were sometimes the key to interpreting an archaeological site. However, there are exceptions, there are sites methodically studied by experts where there are abundant hand axes that are magnificently carved, causing the archaeologists to express admiration for those that produced these works:
Such is the perfection of the carving on some hand axes that they give the impression that the artist took great pleasure in them per se, at least apparently, as the working does not make the pieces any more efficient. At any rate, we are unable to pronounce from this remove whether it was art or the utility of the hand axe that was being sought by making them so well. Although, in our heart of hearts we are sure that they were searching for beauty, aesthetics, as they could have achieved the same efficiency with cruder pieces.
The discovery in 1998 of an oval hand axe of excellent workmanship in the Sima de los Huesos in the Atapuerca Mountains mixed in with the fossil remains of Homo heidelbergensis reignited this controversy. Given that this is the only lithic remains from this section of the site (that was possibly a cemetery), combined with the piece’s qualities has meant that it received special treatment, it was even baptized Excalibur and it became a star item. However, the symbolic meaning of this example in particular, and hand axes in general, has multiplied in recent years, feeding both scientific and more general debate and literature.
The opinion of Martín Almagro Basch, a former professor at the Complutense University of Madrid, serves as a counterargument:
Art is always the same, it is only possible to call someone an artist if they know how to create, within objective limits, the equivalent of the numinous complex experienced individually and expressed in a suitable manner in relation to the society in which the artist lives. In this was it is possible to distinguish an essentially artistic piece from a useful tool, although this may also be beautiful. When a prehistoric man was able to achieve the marvels that are the Acheulean axes, he did not make a work of art; nor did he make a work of art when he used his skill and experience to make a house or adapt rock shelters or caves for living or sanctuary.—Martín Almagro
What seems clear in this controversy is that, basically, a hand axe can be interpreted as a sign of intelligence. However, the paradox is that, within the wide range of Acheulean objects, hand axes are one of the simplest tools to make, they do not require as much planning as other types of object, generally made from flakes that are less striking, but without a doubt, more sophisticated.
It has been noted above that typical hand axes appeared more than a million years ago. Although it is now known that they are the heritage of a number of human species, with Homo ergaster the earliest, up until 1954 there was no solid evidence regarding who fabricated hand axes: in that year, in Ternifine, Algeria, Camille Arambourg discovered remains that he called "Atlanthropus", along with some hand axes. All the species associated with hand axes (from Homo ergaster to neanderthalensis) show an advanced intelligence that in some cases is accompanied by modern features such as a relatively sophisticated technology, systems to protect against inclement weather (construction of huts, control of fire, clothes), certain signs of spiritual awareness (early indications of art such as adorning the body, carving of bones, ritual treatment of bodies, the development of articulated language) etc. Hand axes should be considered as nothing more than another of the many signs of the intellectual development of primitive humans.
- Frere, John (1800). "Account of Flint Weapons Discovered at Hoxne in Suffolk". Archeologia, vol. 13. London. Pages 204-205.
- "Biface". Princeton LDA. Retrieved 16 June 2013.
- Vayson de Pradenne, André (1920). "La plus ancienne industrie de Saint-Acheul". L'Anthropologie, tomo XXX. Publications Elsevier, Paris. ISSN: 0003-5521.. Pages 441-496.
- Gabriel de Mortillet (1883). Le Préhistorique. Antiquité de l'homme. Bibliothéque des Sciences Contemporaines. Paris. Page 148.
- Andefsky, William Jr. (2005). "Biface analysis". Lithics. A Macroscopic Approaches to Analysis. Cambridge University Press. pp. 177–199. ISBN 978-0-521-61500-6.
- "Bifaces en el paleolitico de Sagua". arqueologia de sabeneque. Retrieved 16 June 2013.
- Benito del Rey, Luis (1982). "Aportación a un estudio tecnomorfológico del bifaz, útil del Paleolítico Inferior y Medio" III. Ediciones de la Universidad de Salamanca, Colegio Universitario de Zamora. pages 305-323.
|chapter=ignored (help). pages 305-323.
- Balout, Lionel (1967). Walter W. Bishop and J. Desmond Clark, ed. "Procédés d'analyse et questions de terminologie dans l'étude des ensembles industriels du Paléolithique inférieur en Afrique du nord". Background to Evolution in Africa (The University of Chicago Press). Pages 701-735. (the quote is from page 707).
- An alternative definition can be found on Biface on Diccionario de uso para descripción de objetos líticos by Doctor Giovanna Winchkler in Spanish.
- Kohn, Marek (1999). As We Know it: Coming to Terms with an Evolved Mind. Granta Books. p. 59. ISBN 978-1-86207-025-7.
- Calvin, William H. (2001). Cómo piensan los cerebros. Publisher Debate, Madrid. ISBN 84-8306-378-6..
- Tony Baker (January 27, 2006). The Acheulean Handaxe. ele.net
- Mithen, Steven (2005). The Singing Neanderthals. London: Weidenfeld & Nicolson. pp. 188–191.
- Kohn, Marek (1999), p. 137
- Miller, Geoffrey (2001). The Mating Mind: How sexual choice shaped the evolution of human nature. London: Vintage. pp. 288–291. ISBN 978-0-09-928824-4.
- Keeley, Lawrence H. (1993). "Microwear Analysis of Lithics". The Lower Palaeolithic site at Hoxne, England. The University of Chicago Press, London. ISBN 0-226-76111-8.. Pages 129-149.
- Keeley, Lawrence H. (1980). "The Uses of Hand axes". Experimental Determination of Stone Tool Uses. The University of Chicago Press, London. ISBN 0-226-42889-3.. Pages 160-165.
- González Echegaray, Joaquín y Freeman, Leslie Gordon (1998). Le Paléolithique inférieur et moyen en Espagne. Jérôme Millon. Collection L'homme des origines, Série «Préhistoire d'Europe», nº 6. ISBN 2-84137-064-X. Page 134.
- Domínguez-Rodrigo, M.; Serrallonga, J.; Juan-Tresserras, J.; Alcala, L. y Luque, L. (2001). "Woodworking activities by early humans: a plant residue analysis on Acheulian stone tools from Peninj (Tanzania)". Journal of Human Evolution. 40 (No. 4). Publisher: Academic Press.. Pages 289 –299
- Benito del Rey Luis y Benito Álvarez, José-Manuel (1998). "El análisis funcional de artefactos líticos prehistóricos: la Trazalogía". Métodos y materias instrumentales en Prehistoria y Arqueología (la Edad de la Piedra Tallada más antigua). Volume II: Tecnología y tipología. Gráficas Cervántes, Salamanca. ISBN 84-95195-05-4.
- Semaw, S.; Rogers, M. J.; Quade, J.; Renne, P. R.; Butler, R. F.; Domínguez-Rodrigo, M.; Stout, D.; Hart, W. S.; Pickering, T. et al. (2003). "2.6-Million-year-old stone tools and associated bones from OGS-6 and OGS-7, Gona, Afar, Ethiopia". Journal of Human Evolution 45 (2): 169–177. doi:10.1016/S0047-2484(03)00093-9. PMID 14529651.
- Leakey, M. D. 1972. Olduvai Gorge. Vol 3. Cambridge: Cambridge University Press
- Asfaw, B; Beyene, Y; Suwa, G; Walter, RC; White, TD; Woldegabriel, G; Yemane, T (1992). "The earliest Acheulean from Konso-Gardula". Nature 360 (6406): 732–5. doi:10.1038/360732a0. PMID 1465142.
- Lewin, R., Foley, R. A. 2004. Principles of Human Evolution (2nd Ed.) Blackwell Science, UK. ISBN 0-632-04704-6
- Oms, O.; Pares, J. M.; Martinez-Navarro, B.; Agusti, J.; Toro, I.; Martinez-Fernandez, G.; Turq, A. (2000). "Early human occupation of Western Europe: Paleomagnetic dates for two palaeolithic sites in Spain". Proceedings of the National Academy of Sciences 97 (19): 10666–10670. doi:10.1073/pnas.180319797.
- Pares, J. M.; Perez-Gonzalez, A.; Rosas, A.; Benito, A.; Carbonell, E.; Huguet, R.; Huguet, R (2006). "Matuyama-age lithic tools from the Sima del Elefante site, Atapuerca (northern Spain)". Journal of Human Evolution 50 (2): 163–169. doi:10.1016/j.jhevol.2005.08.011. PMID 16249015.
- Ambrose, S. H. (2001). "Palaeolithic technology and human evolution". Science 291 (5509): 1748–1753. doi:10.1126/science.1059487. PMID 11249821.
- Bourdier, F. (1976). "Les industries paléolithiques anté-wurmienses dans le Nord-Ouest". La Préhistoire française, Tome I (les civilisations paléolithiques et mésolithiques de la France). Sous la direction de Henri de Lumley. CNRS, Paris. Pages 956-963.
- Brézillon, Michel (1985). Dictionnaire de la Préhistoire. Librairie Larousse, Paris. ISBN 2-03-075437-4. Pages 18-19.
- Jacques Tixier, coordinador (1984). Préhistoire et Techologie lithique. Éditions du Centre National de la Recherche Scientifique, Paris. ISBN 2-222-02718-7.
- Michael F. L'Annunziata, ed. (2012). Handbook of Radioactivity Analysis. Academic Press. ISBN 978-0-12-384873-4. Figure 4.27 Page 284.
- Semenov, S. A. (1957). Tecnología prehistórica. Akal editor, Madrid. ISBN 84-7339-575-1. Page 82.
- Hayden, Brian (1989). "From chopper to celt: the evolution of resharpening techniques". Time, energy and stone tools (Edited by Ronin Torrence). Cambridge University Press. ISBN 0-521-25350-0.. Pages 11-12.
- Torrence, Robin (ed.) (1989). Time, energy and stone tools. Cambridge University Press, London. ISBN 0-521-25350-0.
- The orientation of a hand axe relates to its morphological axis. This may be difficult to determine as subsequent flaking may have erased evidence of its position. In this case its orientation can be inferred from the marks on the lower face of the tool stone. The position of the heel can describe using a compass rose: a heel located at the base of the hand axe will be referred to as being in the southerly position. If a heel is to one side, its position will be referred to as being in the easterly or westerly position. If the heel was in the position now occupied by the hand axe's point, which will mean that its original location will have been destroyed, this is called the northerly position. It is also possible to assign intermediate positions (south-east, north-west etc.).
- Victor Chabai, Jürgen Richter and Thorsten Uthmeier, ed. (2008). Palaeolithic Sites of Crimea, Vol 3 Part 2, Kabazi V: Interstratification of Micoquian and Levallois – Mousterian Camp Sites. University of Cologne. ISBN 978-966-650-231-8. Page 203.
- Gabriel de Mortillet (1883). Le Préhistorique. Antiquité de l'homme. Bibliothéque des Sciences Contemporaines. Paris. Page 139. (heel is no longer used to refer to hand axes with an unworked base, instead the actual part of the flake is named).
- Alimen, Marie-Henriette (avec la collaboration de José Zuate y Zuber) (1978). "Les bifaces: considerations morphologiques et technologiques". L'évolution de l'Acheuléen au Sahara nord-occidental. Centre National de la Recherche Scientifique, Meudon, France. Pages 120-121.
- Cotterell, B. and Kamminga, J. (1987) The Formation of Flakes. American Antiquity 52:675–708
- For Jacques Tixier the reworking sometimes has the objective of sharpening the edge so he uses the term reprise (recovery); however, Lionel Balout uses the term secondary retouch or reworking equally; while François Bordes prefers the word regularization: in Alimen, 1978, op. cit., page 121.
- Tixier, Jacques (1960). "Les industries lithiques d'Aïn Fritissa (Maroc Oriental)". Bulletin d'Archéologie marocaine, tomo 3. Pages 107-244. Page 119.
- Bordes, François (1961). "Considérations générales sur les bifaces". Typologie du Paléolithique ancien et moyen. Impriméries Delmas, Bordeaux. Pages 49-55.. The quote is from page 53 and the figure with dimensions is from page 51.
- they are the Elongation index, the Sectional index and the Convergence index (op. cit. 1967)
- Camps, Gabriel (1981). "Les Bifaces". Manuel de recherche préhistorique. Doin Éditeurs, Paris. ISBN 2-7040-0318-1.. Page 59.
- Bordes, François (1961). "Bifaces des types classiques". Typologie du Paléolithique ancien et moyen. Impriméries Delmas, Bordeaux. Pages 57-66.. The Bordes typology singularly fails for cleavers and biface-cleavers, demonstrating an aspect of both types of tool, especially the cleavers, previously faced with more coherence by a classification scheme posed by Bordes’ colleague Jacques Tixier: Tixier, Jacques (1956). "Le hachereau dans l'Acheuléen nord-africain. Notes typologiques". Congrès Préhistorique de la France. XVe Session. Poitiers-Angoulême..
- «Distinguishing between different types of hand axes is not always easy. There is often no room for doubts, however, there are a number of cases where the difficulty is real.» (Bordes, op. cit., 1961, page 49).
- Breuil, H. y Koslowski, L. (1934). "Études de stratigraphie paléolithique dans le nord de la France, la Belgique et l'Angleterre". L'Anthropologie. Tome 42. ISSN 0003-5521.
- Ficron is a word used by farmers in the Somme region. The ficron is the point of a blade located at the end of a pole that allows peasants to push their boats along canals in flooded fields (Bordes, 1961, op. cit., page 58, nota 1).
- Examples of sites where they have been found include such European sites as Valle del Manzanares in Madrid, Spain, Swanscombe in England and La Micoque in France as well as Oum-Qatafa and Tabún in Asia and Sidi-Zin in Africa, among others. Brézillon, Michel (1969). Dictionnaire de la Préhistoire. Éditeur Larousse, Paris. ISBN 2-03-075437-4. Page 156.
- Benito Álvarez, José Manuel (2002). Aportaciones al conocimiento del Achelense en la Meseta Norte. Universidad de Salamanca (Tesis Doctoral, inédita). Page 558.
- Bordes, François (1961). "Bifaces non classiques, disques, boules polyédriques et bolas". Typologie du Paléolithique ancien et moyen. Impriméries Delmas, Bordeaux. Pages 67-69.
- Benito del Rey, Luis (1982). "Comentarios sobre hendidores en España, útiles de Paleolítico Inferior y Medio". Galaecia (Departamento de Prehistoria y Arqueología de la Facultad de Geografía e Historia, Universidad de Santiago de Compostela). Tomo 7/8. Page 17.
- Benito del Rey Luis y Benito Álvarez, José-Manuel (1998). "El análisis tipológico: los bifaces". Métodos y materias instrumentales en Prehistoria y Arqueología (la Edad de la Piedra Tallada más antigua). Volume II: Tecnología y tipología. Gráficas Cervántes, Salamanca. ISBN 84-95195-05-4.
- Leroy-Prost, Christiane; Dauvois, Michel y Leroy, Jean-Pierre (1981). "Projet pour un F.T.A. du groupe des trièdres de l'Acheuléen nord-africain". Préhistoire Africaine. (Réunis par Colette Roubet, Henri-Jean Hugot et Georges Souville). Editions ADPF, Paris.
- Bordes, François (1961). "Pièces foliacées bifaces". Typologie du Paléolithique ancien et moyen. Impriméries Delmas, Bordeaux. Page 41.
- Sonnevile-Bordes, Denise (1961). L'áge de la pierre. Éditeur P.U.F., collection Qu sais-je?, Paris. Page 106.
- Leroi-Gourhan, André (1980). "El Paleolítico Medio". La Prehistoria. Publisher Labour, Barcelona. ISBN 84-335-9309-9.
- Leroi-Gourhan, André (1977). "Esbozo del Arte". El Arte y el Hombre, Tomo 1. Fournier, S. A., Vitoria. ISBN 84-320-2001-X.
- Benito del Rey, Luis y Benito Álvarez, José Manuel (1992). "La Salamanca Paleolítica". Congreso de Historia de Salamanca 1989, Tomo 1. Gráficas Ortega, S. A., Salamanca. ISBN 84-604-3130-4.. Page 160.
- Rivera, Alicia (8 January 2003). "Un hacha hallada en Atapuerca indica que ya había ritos funerarios hace 400.000 años". El País. Retrieved 5 December 2012.
- Almagro Basch, Martín (1958). "La Prehistoria". Historia General del Arte 1. Barcelona: Montaner y Simón, S. A. p. 16.
- Some archaeologists such as Chavaillon (op. cit., 1994) have evidence of hand axes that are 1.2 million years old in Melka Kunturé (Ethiopia), but the oldest, from Konso-Gardula, could be 1.9 million years old: Corbella, Josep; Carbonell, Eudald; Moyà, Salvador y Sala, Robert (2000). Sapiens. El largo camino de los homínidos hacia la inteligencia. Barcelona: Ediciones Península S.A. ISBN 84-8307-288-2. Page 68.
- Arambourg, Camille (1957). "Récentes découvertes de paléontologie humaine réalisées en Afrique du Nord française (L'Atlanthropus de Ternifine - L'Hominien de Casablanca)". Third Panafrican Congress on Prehistory, Livingstone 1955 (Clark, J.D. et Cole, S., Eds.). Pages 186-194.
- Boyd, Robert (2008). How Humans Evolved. New York: W. W. Norton & Company. ISBN 978-0-393-93271-3.
- A. S. Barnes/H. H. Kidder, Differentes techniques de débitage à La Ferrassie. Bull. Soc. Préhist. Franç. 33, 1936, 272–288.
- C. A Bergmann/M. B. Roberts, Flaking technology at the Acheulean site of Boxgrove, West Sussex, England. Rev. Arch. Picardie, Numero Special, 1–2, 1988, 105–113.
- F. Bordes, Le couche Moustérienne du gisement du Moustier (Dordogne): typologie et techniques de taille. Soc. Préhist. Française 45, 1948, 113–125.
- F. Bordes, Observations typologiques et techniques sur le Perigordien supérieur du Corbiac (Dordogne). Soc. Préhist. Française 67, 1970, 105–113.
- F. Bordes, Le débitage levallois et ses variantes. Bull. Soc. Préhist. Française 77/2, 1980, 45–49.
- P. Callow, The Olduvai bifaces: technology and raw materials. In: M. D. Leakey/D. A. Roe, Olduvai Gorge Vol. 5. (Cambridge 1994) 235–253.
- H. L. Dibble, Reduction sequences in the manufacture of Mousterian implements in France. In: O. Soffer (Hrsg.), The Pleistocene of the Old world, regional perspectives (New York 1987).
- P. R. Fish, Beyond tools: middle palaeolithic debitage: analysis and cultural inference. J. Anthr. Res. 1979, 374–386.
- F. Knowles, Stone-Worker’s Progress (Oxford 1953).
- Marek Kohn/Steven Mithen Axes, products of sexual selection?, Antiquity 73, 1999, 518–26.
- K. Kuman, The Oldowan Industry from Sterkfontein: raw materials and core forms. In: R. Soper/G. Pwiti (Hrsg.), Aspects of African Archaeology. Papers from the 10th Congress of the Pan-African Association for Prehistory and Related Studies. Univ. of Zimbabwe Publications (Harare 1996) 139–146.
- J. M. Merino, Tipología lítica. Editorial Munibe 1994. Suplemento, (San Sebastián 1994). ISSN 1698-3807.
- H. Müller-Beck, Zur Morphologie altpaläolithischer Steingeräte. Ethnogr.-Archäol.-Zeitschr. 24, 1983, 401–433.
- M. Newcomer, Some quantitative experiments in hand axe manufacture. World Arch. 3, 1971, 85–94.
- Th. Weber, Die Steinartefakte des Homo erectus von Bilzingsleben. In: D. Mania/Th. Weber (Hrsg.), Bilzingsleben III. Veröff. Landesmus. Vorgesch. Halle 39, 1986, 65–220.
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