|"Most paleolithic archeologists ... tend to believe that the assemblages of humanly flaked stones that we recover in quantities from sites such as Olorgesailie preserve a great deal of valuable information about the craft traditions, the cultural affinities, and the economic life of the hominids who made them. This belief is in part a matter of faith, and there is a danger that in our enthusiasm we may overextend the exegesis of stone artifacts. It sometimes appears that all of us treat stone artifacts as infinitely complex repositories of paleocultural information and assume that it is only the imperfections of our present analytical systems that prevent us from decoding them. But is this really so?" (Issac 1977:207)|
The Acheulean Handaxe
The Acheulean handaxe is over 100,000 years removed from the Paleoindians in the New World, which is about the same distance that exists between this webpage (paper) and my previous ones. Therefore, the reader might ask, how did a Paleoindian archaeologist find himself writing about the Lower Paleolithic? It began in February 2005 while on holiday with my wife in England. One day during the holiday, Nick Ashton and Alan Slade of the British Museum gave me a tour of a number of famous early archaeological sites in East Anglia. One of the sites was Warren Hill, which has produced many handaxes including the one in Figure 1. This tour lit the fuse of interest and research, which ultimately led to this paper.
|0.010-0.020||Late Upper Paleolithic||Homo sapiens||microlithic components of composite artifacts||flakes|
|0.020-0.040||Early Upper Paleolithic||Homo sapiens||blades with steep retouch||flakes|
|0.040-0.150||Middle Paleolithic||Homo neanderthalensis |
& early Homo sapiens
|flake tools from prepared cores||flakes|
|0.150-1.600||Late Lower Paleolithic||Homo erectus||Acheulean handaxe||handaxe?|
|1.500-2.500||Early Lower Paleolithic||Homo habilis||Chopper/pebble tool and flakes||pebble tool?|
"Bifaces (handaxes) were the first Paleolithic artifacts to be recognized as such and were illustrated as early as the end of the eighteenth century by John Frere" (Debénath & Dibble 1994:130). Their large size and symmetry are probably the reasons for this early recognition. These same qualities were also probably the reason the handaxe was/is perceived as an intentionally manufacture tool, a tool made to a mental template. As a result, G. de Mortillet named them "coups de poings" in 1883, which is the source of the English terminology of handaxe. In 1920, Vayson de Pradenne introduced the term "biface" into the literature. Today, Acheulean biface has become the most commonly used term because it has no implied function (Debénath & Dibble 1994:130). However, in this paper, I will be politically incorrect and continue to use the term "handaxe". When I use the terms biface or "early stage biface", it will mean the broader connotation that has no temporal or spatial meaning.
François Bordes (1961) and Derek Roe (1967) independently studied handaxes and developed different classification schemes for the variation in morphology that they observed. However, neither could explain the variation and both admitted that they didn't know what function(s) the handaxe served (Bordes 1968:64; Roe 1981:271). McPherron (2003:55-75) has explained the variation with a reduction model that has the handaxe beginning long and pointed and evolving to an ovate shape as it is resharpend over its use life. Yet, he also admits that the function, which required the resharpening, is unclear to him. Contrary to the reduction model, Nick Ashton and Mark White have demonstrated that roughouts (handaxe preforms) from excavations of the Boxgrove site in England "... have the same ranges of shapes as the bifaces (handaxes) and suggest that it is the shape of the original nodule that influences the form of the biface" (2003:115).
On the other side of the coin, there is a smaller group of researchers who hold that the handaxe was a by-product of flake creation. I belong to this group and have expressed some early thoughts on this subject in my webpage The Lithic Containers of the Archaeological Record. The earliest suggestion that handaxes might be flake cores, which I have found in the literature, is by Brian Hayden (1979:15) who wrote:
|I would argue that handaxes make more sense as pieces carried about by individuals, primarily for convenient use in woodworking ... and as a source of flakes. It furthermore seems plausible that their shape is a function of economical use of parent material... .|
Harold Dibble didn't directly suggest that the handaxe was a flake core. However, he did challenge J.A.J. Gowlett who "... argued that samples of early Middle Pleistocene Acheulean handaxes from Kilombe, Kenya, show 'a high degree of standardization, and must imply a well-defined mental image of the desired end-product'" (1989:421). Dibble then proceeded to demonstrate that the high correlation between length and width (Gowlett's argument) can be a result of randomness, technological constraints and methods of classification (1989:423-424).
Iain Davidson and William Noble are strong advocates of the handaxe being a flake core. They suggest that belief in the handaxe as the desired product is "... the 'finished artefact fallacy', which has bedevilled the traditional study of stone artefacts, and introduced a false understanding of what it is that artefacts tell us about hominid abilities" (1993:365).
In summary, the above debate is simply about how the handaxe came to be in the archaeological record. Was the handaxe the intended tool and the flakes removed during its creation, the by-product? Were the flakes only occasionally, expediently used as tools? Subsequently, was the handaxe curated and/or transported for future use as a tool? OR, was the handaxe the by-product of removing flakes, which were the intended tools? Was the handaxe occasionally, expediently used as a tool? Subsequently, was the handaxe occasionally transported for a future source of flakes?
|Note 1 -- I only refer to Homo erectus, but I mean Homo erectus and any other critters that may have been responsible for the Acheulean handaxe.|
The Acheulean handaxe's morphological variation is problematic. Depending on one's perspective, the morphology has immense variation or it is very uniform. The definitions in the literature vary somewhat depending on this perspective. According to Nick Ashton and John McNabb, "the modern 'mental template' of a biface (handaxe) is based on a symmetrical tool that has a distinct butt and tip and is bifacially worked over most of the two faces to both thin and shape it into a specific design" (1993:183). Glynn Isaac says the classic handaxe from Olorgesailie, Kenya has: "1) A variable amygdaloid or oval plan form, 2) Lenticular sections, 3) Trimming scars penetrating most of both faces, and 4) A sharp edge running all around or almost all around the perimeter." However, this classic definition applied to only 28% of the 600+ handaxes at Olorgesailie (1977:117-120).
Derek Roe's definition (1981:74) as it applies to handaxes from Britian and Northwest Europe is as follows:
|Handaxes are shaped tools, usually of medium to large size by standards of flint artefacts in general, characterized by the presence of a cutting edge which normally extends around most of the circumference. ... the vast majority of handaxes are fashioned by bifacial flaking, though this does no mean that the whole of each face is necessarily worked: cortex patches may be left, or, where the implement has been made from a large flake rather than from a nodule, areas of the flake's bulbar surface may survive. Handaxes as a class include a considerable variety of shapes (in the sense of plan-form). These shapes usually tend toward regularity and symmetry, but only rarely are they so symmetrical in all respects that a distinct 'tip' and 'butt' cannot be defined. Handaxe tips may be more or less pointed, or tongue-like, or rounded, but occasionally a squared transverse cutting edge may be found at the tip end. Butts may be anything from fully and delicately worked with complete cutting edges to wholly unworked or just roughly shaped here and there to provide a hand-hold. In profile handaxes vary from thick and irregular to flat and symmetrically lenticular, according to the nature of their flaking.|
To these general definitions, I would like to offer Table 2, which has some additional, specific characteristics for the handaxe.
Age, as a characteristic of the Acheulean handaxe, may trouble the reader. One normally expects the index fossil to be the temporal marker instead of being defined by a temporal period. However, the handaxe is just that. It continued to exist in the Middle Paleolithic as the Moustérien de Tradition Acheuléenne or MTA (Bordes 1968:102; Gamble 1986:165; Roe 1981:235) and after that as an early stage biface. The idea that the Acheulean handaxe continues on into more recent times under the different names is not that radical. The Oldowan pebble tool continued into the Acheulean times and beyond (Clark 1996:85-86). In the words of Grahame Clark, "it is not so much that one form of technology gave place to another as that technical possibilities are enlarged by the adoption of new processes" (1969:30).
Metrics presented in Table 2 were derived from several sources and represent 7550+ handaxes. By far the largest single source was Derek Roe's 1967 dissertation, from which I obtained summary information for 38 British sites/collections. This data was supplemented by one (1) additional collection in England (Fox 1969), 24 sites in Africa and five (5) sites in India. There will be more discussion about these metrics later in the paper.
Dense concentrations of handaxes are a characteristic of many Acheulean sites. Kathy Schick (2001:465) is one of the few authors who recognizes this characteristic and asks the question, "why do we find so many bifaces left at so many Acheulean sites?"
Local material, as I define it, is lithic material in the archaeological record that is from no more than 40 kilometers (25 miles) from its source. Some readers may feel this definition encompasses too much area and that is their prerogative.
|Note 2 -- see Variation in Paleoindian Lithic Assemblages Through Time and Contrasting the Lithic Technologies of Mesa and Folsom|
Nodules or large flakes have been recognized as the beginning forms of the handaxe (Gowlett 1995:198; Gowlett, Crompton & Yu 2001:612; Issac 1969:16; Issac 1977:116; Roe 2001:498). This is obviously the result of material type availability. England has cryptocrystalline material and the handaxes from there were made on nodules. The African sites have the more intractable rocks, such as quartzites and basalts, and the handaxes from there were made on large flakes.
I observed battered edges on nearly the entire perimeter of the handaxes from the Boxgrove sites in West Sussex, England. These handaxes are made of high quality flint and are in "fresh" or "mint" condition, as they had not been rolled or tumbled by processes subsequent to being discarded by their makers. This battering appeared to have been caused by repeatedly striking the edges with a hammerstone. This action creates a blunt edge with many tiny step fractures scars on the faces. This battering is also present on the platforms of the flakes from Boxgrove, which means the edges were battered before the flakes were removed. No evidence of grinding the edges or dragging a hammerstone along the edges was observed. Occasionally, a handaxe did exhibit an unbattered length of edge where a tranchet flake had been removed. This suggests that after the removal of the tranchet flake there was no further battering. The reader should know that I am assuming this edge preparation by battering is associated with all Acheulean handaxes regardless of time or continent.
Hinge flake scars are common on handaxes that exhibit considerable refinement or thinning. They are a product of percussion, especially hard hammer percussion, when the biface approaches a width-to-thickness ratio in the range of 2.0-2.5.
Differences in belief by groups can often be traced to their different paradigms and/or experiences. As previously stated, I believe the Acheulean handaxe was the by-product of removing desired flakes. Contrary to my belief, the majority of Lower Paleolithic researchers believe the handaxe was the desired tool and the flakes were the by-products. So how do disagreeing groups resolve their conflict? Both try to persuade the other, via logic, that their interpretation is correct. Therefore, the following is my attempt at that logical persuasion.
The Lower Paleolithic researchers who believe the Acheulean handaxe was the desired product do not find their justification in its function, since its function is not understood (Bordes 1968:64; Debenath and Dibble 1994:130; Gowlett, Crompton and Yu 2001:612; Isaac 1977:12,144; McPherron 2000:73; Roe 1981:271). Instead, they find their justification in its unchanging morphology. For a million plus years, its basic shape remained constant as it spread across three continents. It has a tip, a butt, and often symmetry in three dimensions. Its length is rarely longer than twice its width, and Gowlett has demonstrated at Kilombe, that a linear relationship between length and width explains 69% (R=0.83) of the variation (1995:202). Issac proved there was a strong correlation between the length/width ratio and length regardless of sites or continents (1977:139). Further, its width is rarely greater than three times it thickness. This unchanging morphology is, therefore, proof that the handaxe was constructed to conform to an unchanging, deeply engrained mental template.
The use of local material to create the vast majority of handaxes in the archaeological record is also recognized and noted by most researchers (Ashton 1992:137; Ashton and White 2003:115; Gamble 1986:331-332; Isaac 1977:87-117; McPherron 2003:60; Noll and Petraglia 2003:45-47; & Schick 2001:470-476). At the same time, this fact is usually presented as normal, expected, and unimportant. However, when an occasionally rare handaxe made of exotic material is found, then this is important. It is well documented and discussed. It fits their belief. It is proof of intention to make a handaxe to the mental template and then transport it (Gowlett 1995:194-196).
A fact that is more problematic to these researchers is that the vast majority of handaxes have been found in dense concentrations. Often, this fact is ignored and it is left to the reader to surmise it by dividing the number of handaxes by the area that produced them. Issac (1977) and Schick (2001) are a few of the researchers who note the high concentrations and attempt to explain them.
|Note 3 -- Fluvial contexts also contain the hardest rocks, which include the knappable ones. So, a different argument can be made that a fluvial context concentrates knappable rocks, en lieu of the knapped artifact. Therefore fluvial contexts are often lithic sources.|
Within the limits of the handaxe's morphology there appears, in the more recent Acheulean, a handaxe with more flake scars (Issac 1977). The flake scars on this handaxe are then naturally smaller and the handaxe is thinner and more symmetrical. The appearance of this handaxe has caused some researchers to argue for the introduction and use of a soft hammer (Bordes 1968:52; Clark and Kleindienst 2001:47-48; Gowlett 1995:202; Issac 1977:142; Schick and Clark 2003:17). This more scarred handaxe has also caused some researchers to suggest there was an evolution in the mental template, which is from crude to refined (Ashton and McNabb 1993:182; Bordes 1968:51-52; Clark 1969:39; Gowlett 1995; Roe 1968:62&71; Schick and Clark 2003:17; & Wynn 2002:391). The soft hammer and evolution arguments are attractive; however, neither have been rigorously demonstrated. I will personally argue against the soft hammer concept later in this paper. The evolution suggestion has trouble because the thicker, fewer scarred handaxes continued to coexist along side the thinner, more scarred variety. Plus, without a knowledge of the handaxe's function, the suggested evolution cannot be argued to be functional. It is only, at best, an aesthetic evolution.
My justification for believing the handaxe was a flake core, the by-product of flake extraction, is also based on its unchanging morphology. However, I see the unchanging morphology as the natural outcome of the limited physical capabilities of Homo erectus. The handaxe without its temporal association is just a crude, early stage biface. I personally have studied early stage bifaces from the Solutrean in France, Paleoindians in Alaska, and the Archaic in West Texas. Similar to the handaxe, these too were found at their quarry (material source) and were flake cores. In my earlier paper, The Lithic Containers of the Archaeological Record, I define a lithic container as "... a core of local material, which means it is found at the quarry, and it was reduced with hard-hammer percussion." I discussed three types in the paper: biface, Levallois core, and blade core. I point out that in the archaeological record their density is highest at the lithic source. Does the Acheulean handaxe sound like a lithic container? Yes it does! It is a crude, early stage biface found at the source of the lithic material and with a temporal definition between 1,600,000 and 150,000 years ago. In the following I will elaborate on the reasons for my beliefs.
A Trip to the British Museum and then on to a Bob's Backyard
|Indeed, it is possible to offer new pronouncements on stone tools (handaxes) assemblages, and doubtless on their implications for past human behavior, without ever seeing or handling the artifacts themselves, but simply using and manipulating numerical data recorded, stored and made available by someone else. How very old-fashioned of me to think that there might be something wrong with that, and also to be delighted that the contributions in this volume are mainly based on careful first-hand study and personal collection of data. (Roe 2003:274)|
|The literature nevertheless shows an extreme divergence in views expressed (about handaxes being tools) -- chiefly disagreement with archaeologists whose work is based in later periods, ... (Gowlett 1995:193)|
I am guilty of both of the above accusations. I have seen very few handaxes and my expertise is in more recent periods. I am also 61 years old and doubt I will ever view one-tenth of the handaxes that Roe or Gowlett have studied. That said, I did have a desire to see at least a few before I wrote this paper. So I made a trip to the British Museum in October 2005, and thanks to the hospitality of Nick Ashton and Alan Slade I was able to study approximately 100 handaxes and an unknown number of flakes over a three-day period.
The British Museum houses the Acheulean material from the Boxgrove, West Sussex site. Boxgrove is one of the few Acheulean sites in England with "... in situ working floors" (McNabb 2000:439). As a result, the artifacts look like they were made yesterday, instead of 250,000 years ago or more. These fresh handaxes and flakes were my primary focus because I wanted to see the evidence for the soft hammer percussion, and Boxgrove is one of the sites for which this argument is made. In fact, there have been a number of reported organic hammers found there. However, I was not able to view them during the visit as they were housed in another museum.
The evidence for soft hammer percussion, in addition to large thin flakes, that I was expecting to find were ground platforms, margin striking, and lipped flakes. I did not see any edge grinding. Instead, I saw edge battering. Battering being the result of hammering the edge with a blow directed straight into it. This battering created a dull, rounded-over surface with many tiny cracks and step flake scars. In most cases, the entire perimeter of the handaxe was battered with the exception of the prior location of the platform of the last flake removal. I even remarked to Nick that it was easy to locate the last flake removal, because the edge was not battered at that location. This led me to believe that battering was the method used to prepare the edge for the next flake removal. In different words, battering was used to create a stronger margin by removing the knife-edge created by the previous flake removals. When I checked the platforms on the purported soft hammer flakes, they were also battered. However, I saw no evidence for margin striking because the battering had essentially remove the margin and left a rounded over surface. Possible damaged platforms resulting from hard hammer percussion were hard to recognize because of the prior battering. I did see a number of lipped platforms, but again these platforms had been battered.
I also saw evidence for use-as-a-tool on the handaxes and flakes. On the perimeter of some of the handaxes, there were often short lengths, two to three centimeters, of edge where the battering had been obliterated by usage. This usage was expressed as notches, spokeshaves, and scraping edges. On the flakes certain lengths of the edge showed signs of usage and as similar to the handaxe, this use was not on every flake. Occasionally, I would see a flake with a modified edge that I interpreted as backing or dulling of the edge. I believe this was done to allow one to apply force at this location with a finger. In all cases the use evidence on both the handaxes and the flakes appeared to be expedient behavior.
In summary, the evidence I saw for soft hammer percussion was mixed. I saw large, thin flakes, both flat and curved, that occasionally had lipped platforms. Edge preparation was battering, not grinding. I could not identify margin striking because the margins were lacking. I could not discern crushed platforms because of the edge battering. I did see evidence of expedient use on both the handaxes and the flakes. However, this use evidence was on, maybe, 50% of the handaxes and 20% of the flakes.
When I returned home, I soon made my way to Bob Patten's backyard. Bob is an accomplished knapper that I have collaborated with over the past 10 years. (See Bob's webpage at www.stonedagger.com.) I had brought to the backyard a bucket of chert nodules from the Edwards formation near Iraan, Texas, and I wanted Bob to do some experimental knapping. Using the nodules that I had brought, I asked Bob to: 1) extract usable flakes - don't make handaxes, 2) only use hard hammer, and 3) only prepare the edges by battering. I have sat in Bob's backyard many times in the past with Bob doing the knapping and I doing the watching. However, this afternoon turned out to be very special. Some of the Bob's results were expected, and some were unexpected and very enlightening.
Long before I visited the British Museum, I believed that the flake extraction process would create bifaces that could be classified as handaxes. And, this did happen. The unexpected results came from the battering. When Bob battered the edges of the biface, it caused the thicker areas to standout or rise above the rest of the edge. It created isolated platforms at the thickest locations along the edge. Bob didn't have to identify these locations and develop them, the battering process did it for him. At times it even revealed locations Bob would not have considered. From these locations and with a nearly perpendicular blow that just kissed the edge, Bob was able to remove large thin flakes.
The second unanticipated result was the unusual number of lipped flakes this process created. Bob attributes these to his method of holding the hammer. He held the round stone hammer with the tips of his fingers, index and little fingers on the sides and the two middle fingers on the top. His thumb was not involved with the holding at the time of impact. One might call this a 4-jaw chuck grip without the thumb. Bob taught himself this grip many years ago in order to create larger flakes. He said it removes the damping effect of a firmer grip. For myself, I am not sure his holding technique was responsible for the lipped flakes. It could have been that the battering, which might have created weaknesses in the edge, permitted some flakes to initiate from locations away from the point of impact. However, the fact remains that Bob made lipped flakes with a hard hammer.
As Bob extracted flakes and the biface became thinner, it became more difficult for Bob to find locations that would yield acceptable flakes. The edges were becoming too acute. Finally, Bob would set the biface aside and begin again, with a fresh nodule. The biface that Bob had set aside was exhausted.
After Bob had exhausted two or three bifaces, I ask him to try to remove a tranchet flake as he was finishing with the next biface. With Bob's skill this was an easy request. He cut the tip of the biface off, making it an excellent cutting tool. I asked him to do it a second time as the next biface was becoming difficult to work. This time his tranchet flake scar angle cut deeper into the biface resulting in a less acute cutting edge at the tip. Bob immediately noticed that this new edge, with the less acute angle, was an ideal platform for removing an additional flake. This he did and this flake traveled along the edge of the biface toward the butt. This second flake also created a less acute edge, which provide a launching site to extract even more flakes from the face of the biface. The tranchet flake had rejuvenated the biface and permitted the extraction of additional flakes from what would have been exhausted core. In a sense, the tranchet flake was analogous to a blade core tablet.
To summarize the experiments in Bob's backyard, Bob unintentionally created bifaces, which had the morphology of a handaxe, by intentionally extracting flakes with hard hammer. He used only battering to prepare the edges and the battering automatically developed the striking platforms. He held the hammer stone with a 4-jaw chuck grip. Finally, we discovered that the removal of a tranchet flake could be an excellent way to extend the life of the biface core. It is the blade core tablet of bifacing.
Soft Hammer Percussion and the Handaxe
The archaeological understanding of flint knapping comes from three sources: 1) the modern flint knapper, 2) the archaeological record, and 3) the physics of flake mechanics. Modern knappers have had the most influence on this understanding and physics the least. So, here are what a few of the modern knappers have to say about soft hammer percussion and the flakes it produces.
|"A (soft-hammer flake) should be relatively thin and flat, with a tendency to expand in the width from the platform. ... (Soft-hammer flakes) are often somewhat curved. ... The trait most characteristic of soft-hammer percussion seems to be the frequent lipping of the interior of the platform. ... As a group, the traits above are considered characteristic of soft hammer percussion because they are common in an assemblage of flakes produced by soft hammer, but relatively rare in an assemblage of hard-hammer flakes. However, all these traits, singly or in combination, can be produced by hard-hammer percussion." (Whittaker 1994:185-187)|
"While accurate detachments and lips do not guarantee a soft hammer made flake, a preponderance of this form of initiation (bending) is at least an indication of tool preference." (Patten 1999:83)
"My experience is that the flake types possible with competent use of the hammerstone have considerable overlap with billet flaking scar types; that hammerstone flaking is capable of producing flakes, flake scars, and bifaces almost indistinguishable from those produced by billet; and that interpretation of the archaeological record may have been considerably skewed because of ignorance of these facts." (Callahan 1979:166)
Bruce Bradley has told me numerous times that he can produce any flake type with any type of hammer.
The modern knappers are telling us that hard hammer percussion is capable of producing the flake types and scars that we associate with soft-hammer percussion. As Whittaker and Patten point out, it is the abundance of one type or the other that is more indicative of hammer type than is a single flake or scar.
Flake mechanics tell us that the thickness of a flake is controlled by where the blow is applied. The further the distance from the edge of the core the thicker the flake will be. This is also called platform thickness. Thick flakes have flat ventral (bulbar) faces and tend not to be contolled by the dorsal face. Ventral surfaces on thin flakes parallel the dorsal surfaces. If the dorsal surface is flat the flake is flat. If it is curved, the flake is curved. So, all one has to do to get "relatively flat and thin flakes with small bulbs of percussion" is to remove flakes from flat surfaces and strike near the edge. Soft hammer makes striking near the edge an easier task because it does not crush the thin platform as readily. However, this problem is overcome by proper platform preparation.
Here is what the modern knappers say about soft hammer percussion and the cores it produces.
|"A soft hammer is particularly useful in thinning, flattening, and shaping bifaces ... " (Whittaker 1994:185). When bifacing, Whittaker switches from hard hammer to soft hammer at a width/thickness ratio of approximately 2.0 (1994:202).|
"Although stone hammers are serviceable through the whole range of percussion stages, organic materials are often considered superior, especially for later stages" (Patten 1999:29).
"... it seems that the w/t ratio capabilities of hard hammerstone percussion may rarely exceed 3.00. Soft hammerstone percussion, on the other hand, may be expected to exceed 10.00 when restricted to materials graded from 1.0 to 3.5" (Callahan 1979:169).
The modern knappers are telling us that thin bifaces, as measured by width/thickness ratio, are difficult to achieve with hard hammer percussion. Callahan suggests there is an upper limit of 3.0. I have previously suggested a value as high as 4.5 in my Flake Creation Webpage, which I now feel may be a stretch. That said, the handaxes from around the world have an average width/thickness ratio of 1.9 and 95% have a value of less than 3.0, which is definitely in the range of hard hammer.
Soft hammers or billets, as they are often called, are high investment, high maintenance tools when compared to hard hammers, which are rocks. First, a desirable antler, bone, ivory, or piece of wood must be acquired. The modern knapper usually purchases it at a knap-in. Next, it needs to be cut and ground to proper size and shape. The modern knapper uses a hacksaw and grinding wheel. When in use, it has to be constantly refurbished by grinding. Finally, to avoid manufacturing it every time it is needed, it must be transported. Compare this to picking up a rock at the location of the knapping event and discarding it when finished.
Finally, the human hand has been evolving with our ancestors. Australopithecus afarensis (Lucy) was not capable of the power grip and could not use a billet as one would use a hammer (Aiello and Dean 1991:388). Homo habilis' hand was more like modern humans and possibly could have employed the power grip to some extent (Aiello and Dean 1990:392). Unfortunately, I was unable to find any information concerning Homo erectus' hand. John Gurche told me that there have been no fossil hands found for Homo erectus (2005, November personal communcations). By the time of Neanderthal, the hand "... was strong and powerful and, although not identical to modern humans in its morphology, the Neanderthal hand was capable of the wide range of complex manipulative functions that characterize the human hand" (Aiello and Dean 1990:394). That said, I question whether Homo erectus would have been capable of wielding a large organic billet that was large enough to create the flake scars that are found on the handaxe.
In summary, the purported Acheulean soft hammer flakes and flake scars could have been created with soft hammer or hard hammer. The same can be said for the handaxe. However, since Homo erectus was not deriving the benefits of soft hammer percussion, which are thinner bifaces, and may not have actually had the strength and manipulative ability to control a soft hammer, I can find no logic for them to have used soft hammers on a routine basis.
|Question - "What is one plus one?"|
Accountant's answer -- "Two point, zero, zero. Always has been and always will be."
Statistician's answer - "Approximately two. Somewhere between 1.98 and 2.02."
Politician's answer after getting up and shutting the door - "What would you like it to be?"
The morphology of the handaxe is characterized in the literature with metrics. There are several different schemes, but they all have in common the three measurements of maximum length, maximum width and maximum thickness.
In 1969, William Fox, a student at the University of Toronto, took measurements and reported on 600 handaxes stored at the Royal Ontario Museum (ROM). These 600 handaxes are probably from Cannoncourt pit and the adjacent Cooper's pit at Furze Platt, Maidenhead England. They were collected by Llewellyn Treacher before 1920 based on the dates on some of the artifacts. They found their way to Z. A. Lash, who ultimately donated them to the museum (Fox 1969). These ROM handaxes are a separate collection from the 473 from Furze Platt stored at Oxford and reported on by Roe (1967). In 2005, William Fox, now with Parks Canada, permitted me access to his raw data and report of 1969. I digitized his data and with his permission have made them available at Furze Platt Handaxes Housed at ROM.
This ROM collection is the largest of two sets of data for which I have individual artifact measurements. I have assembled addition data from the literature, which are average values from 68 other sites and collections representing Africa, India and England. These values are presented in Table 3.
Figure 2 is a plot of the width/thickness (W/T) versus length/width (L/W) ratios for the 600 individual handaxes from Furze Platt at the ROM. In the literature various authors have proposed schemes using additional measurements, such as the location of the maximum width, that would subdivide these 600 handaxes into sub-groups. Significance was then believed to be associated with these sub-groups, but that significance was never defined. Additionally, for any given sizeable site/collection from Acheulean time or space, all of these sub-groups are always present as they are in Figure 2. In my opinion there are no subgroups in Figure 2. Instead, I see normal variation resulting from a single process. The purple diamond in the middle is the numerical average for the collection.
Figure 3 is identical to Figure 2 with the addition of the yellow triangles, which are the average values from the 68 handaxe sites/collections listed in Table 3. The purple diamond is, again, the average value for the 600 handaxes in the ROM collection. The purple triangle is the average value for the 473 handaxes, which are also from Furze Platt but from the Oxford collection. Notice the difference between these two average values. I suspect some of the readers are probably asking why they do not overlay each other? Others are satisfied with their separation knowing that sample means from a population are rarely, if ever, the same.
A second point to be made about Figure 3 is that the average values for the 68 sites, which represent enormous time and space, lie totally within the variation of the 600 individual handaxes from Furze Platt. Some readers make look at the variation between sites and argue for their diversity. Other readers, myself included, see this variation between sites as normal and minimal. It is a product of sampling from a larger, single process. This is the fundamental argument for this paper.
The L/W and W/T ratios in Figure 3 are not independent. There is a trend from upper-left to lower-right. The two parameters are related by an equation of the form width = C1*ln(L*T)+C2. This is the Dynamically Loaded Model, which I first developed in my Lithic Container paper.4 Figure 4 presents the 68 sites/collections in the form of the Dynamically Loaded Model.
|Note 4 -- In the Lithic Container webpage, the Dynamically Loaded Model was of the form, width = C1*sqrt(length*thickness)+C2, which is a subset of the natural log form. The natural log form is the more general equation.|
In Figure 4 we see the three Homo sapiens sites/collections align well with the Acheulean sites/collections. The reason for this agreement is that the condition of length, width, and thickness represented by the exhaustion line is not humanly controlled. It is controlled by physics. It is the condition of vibration during percussion when the second order wave starts to create hinge flakes. (See my Flake Creation Webpage.) When this begins to occur the core becomes problematic for flake extraction and it is discarded and replaced with a fresh one.
The fact that the Homo sapiens sites/collections align well with the Homo erectus ones in Figure 4 does not mean that the bifaces from each were reduced with the same techniques. They were not. The Homo sapiens ones were reduced with a process that is more physically and mentally evolved than the process used by Homo erectus. However, before I explain the different processes, I want to point out two of the differences they yield.
The most obvious difference has been noted many times in the past. In Roe's definition of a handaxe he says they are "... usually of medium to large size by standards of flint artefacts in general ..."   (1981:74). This is indeed true. See Figure 5, which was created to give the reader an appreciation of the size of the handaxe. The small one is the same one pictured at the beginning in Figure 1 and is from Warren Hill, England. The large one is in the top 5% by size. It is 240 mm long and is from Olorgesailie, Kenya.5 The hand, of course, is the author's, and is somewhere between average to large. Another way to appreciate the size of the handaxe is to return to Figure 4. All 68 handaxe sites/collections contain bifaces larger than the Alaska and West Texas bifaces. Only the Solutrean site has bifaces of comparable size.
|Note 5 -- From the Tony Pfeiffer collection.|
|Figure 6 -- Comparison Between the Average Values from 68 Handaxe Sites/Collections and Three Homo sapiens Sites/Collections|
Some researchers may try to suggest that this lack of variation in the handaxe in Figure 6 is the product of culture. It is not. Homo erectus was not constrained by a mental template, but instead they were unable to deviate from this thick and chunky by-product because of their lack of physical abilities. The handaxe is the result of only inertial support knapping. Homo sapiens used this support, but they also employed external support.
External and Inertial Supports
Flake creation is accomplished by applying a force to a stationary core. During pressure flaking the resistance of the core to movement is the holding hand, which is an external support. To better understand this, lay a core on a smooth table. Try to remove flakes from the core with the pressure tool, but do not hold the core. It can not be done. You just push the core around the tabletop. The core requires an external support to hold it stationary.
Percussion flaking introduces a second support, which I will call the inertial support. The inertial support can be understood by imagining a large core lying on a very soft pillow. Strike the core with a hammer. A flake is removed and the core does not move. Now place a small core on the same pillow and strike it with a hammer. This time the small core jumps away from the hammer and a flake is not produced. What supported the large core and not the small one? It was its large mass or inertia, which is the inertial support. In Newton's words, the core applied an opposite force to the percussion blow, which was equal to its mass times its acceleration.
To simplify the understanding that two supports contribute to percussion flaking, one can combine them into a single resultant force and location. Figure 7 is an idealized plan view of an early biface core. The external support is located at the bottom-right of the core and represents the holding hand or an anvil. The inertial support is located at the center of mass. As stated above, during percussion flaking both the external and inertial supports are operating. These two supports can be mathematically combined into a single resultant support located on the line between the two. If the core is large, the majority of the support is inertial and the resultant support is located near "A". On the other hand, if the core is small, then the external support is dominant and the resultant support is located in the neighborhood of "B". Additionally, the external support is applied by the knapper and its location can be placed anywhere around the perimeter of the core. As a result, if the core is small the knapper can force the resultant support to be at almost any location within the core.
The location of the resultant support is extremely important because the percussion blow should always be directed toward this location. If it is not, then some of the energy to create the flake is lost in rotating the core around the resultant support. In Figure 8, Blows A, B, and C are correctly directed as they are all pointed toward the resultant support. Blow D is not because its energy causes the core to rotate instead of creating a flake. The reader may argue that flakes were often removed from blows that are directed similar to D. This is correct, but in that case the knapper had positioned his external support at a location that caused the resultant support to be somewhere inline with Blow D.
Again, the resultant support is a combination of the inertial support located at the center of mass and the external support. For small mass cores, the resultant support can be positioned anywhere the knapper chooses and he does this by his application of the external support. This is not true for large mass cores because it is difficult for the knapper to apply an external support that is of equal magnitude to the inertial support. Therefore, in large mass cores the knapper is forced to direct the blows toward the inertial support, which is the center of mass. This is the reason that the flake scar directions on the handaxes are directed to the center of mass. Even on the long pointed handaxes, as in the one from Olorgesailie in Figure 5, the flake scars on the tip start far out on the point and travel toward the center of mass in the butt. It is also worthy to note that earlier scars may not be directed exactly toward the current center of mass. This is because the center of mass is always moving as flakes are removed from the core. As a result, early flake scars were directed toward earlier locations of the center of mass.
The resultant support not only controls the direction, it also controls the maximum possible length of the flake. Cracks that create thick, usable flakes cannot travel beyond the resultant support. This is the reason blade cores should be anviled at the tip (location of resultant support) when removing blades. It allows the crack to run to the end of the core. To further explore this concept, imagine a blade core that has the resultant support located at 1/3 of the length of the core. The crack that creates a thick flake will travel straight until it reaches this support and then it will try to wrap around it. The result is then 1) a reverse overshot, 2) an ugly step flake, or 3) an embedded crack that tried to wrap around the resultant support and died. If a thinner flake is attempted, it can be made to feather out at the location of the support, but it will not travel any further. Only, the very thin "skimmer" flakes, which follow the contour of the surface, can be made to travel beyond the resultant support. However, these flakes do not alter the core morphology and have little tool valve.
Referring back to Figure 8, and remembering that usable flakes can not be longer than the distance to the resultant support, which blow A, B, or C would the reader take first? I hope the reader chose A because this has the potential to produce the largest flake. The next location might be at C or it might be another one next to A. It would not be B. This strategy of removing the longest flakes first causes the knapper to remove flakes from the longest dimension, which shortens the longest dimension.6
|Note 6 -- Bob Patten explained this to me before I understood the physics behind the statement.|
A second bit of wisdom from Bob Patten concerns beginning with a new piece of material. He says the best places to remove the first flakes are at the corners or discontinuities in the continuous edge. The scars resulting from the removal of these first flakes, then create good locations for further flake removals. So, the knapper begins by removing flakes from the corners that are furthest from the center of mass with blows directed toward the center of mass. These would be blows similar to blows A and C in Figure 8. After a few flake removals from these locations, the biface now has the start of a tip and the archaeologist can identify it as a handaxe. Further flake removals around these locations just enhance its handaxe look.
Large Biface Cores
|"What rocks would work best (for throwing)? Large rocks, but also rocks whose shape had less air resistance. Most rocks tumble, but flat rocks ... will sometimes rotate in the style of a discus or frisbee, keeping the thin profile aligned to the direction of travel and thereby minimizing drag." (Calvin 2002:404)|
By now the reader knows I do not believe the handaxe was created to be a frisbee. However, I wanted to again remind the reader that they are large bifaces because I want to return to my earlier discussion of the experimental work in Patten's backyard. I now realize our replication efforts were not as exact as I would have wished. We were correct in using hard hammer, battering, and the strategy of flake extraction. However, we wrongly used the hand and knowledge of Homo sapiens. This is now very obvious to me, but at the time, I had no idea we were making this mistake. From the beginning, Bob selected nodules from the bucket that were already smaller than the average handaxe found in the archaeological record. He did this unconsciously. The smaller nodules allowed him some control over the resultant support that he would not have had with a larger nodule. This control allowed him to direct flakes in directions other than the center of mass. It also allowed him to make flakes run past the center of mass and thin the biface beyond the usual 2.0-2.5 width/thickness ratio associated with the handaxe.
Homo erectus did not select small cores from which to extract flakes (make handaxes). I propose he chose large cores because he did not have the manual dexterity to externally support them and, therefore, he had to rely on the inertial support. He just let them lie flat in his hand or on his leg. This inertial support knapping meant all blows had to be directed toward the center of mass. Flakes scars could not pass the center of mass so the handaxe remained relatively thick. Additionally, with numerous flake removals the handaxe became smaller and more ovate or discoid in shape because the blows were being directed from the furthest edge from the center of mass toward the center of mass.
Homo erectus Behavior
The behavior model that I envision for Homo erectus has him living at sweet-spots on the landscape that are defined by water and the abundance of food and lithic material. This explains the association of dense concentrations of handaxes with fluvial deposits. I do not see Homo erectus wandering the landscape in search of food and transporting lithic material. Obviously, there was movement of individuals at times from one sweet-spot to another, since they managed to populate three continents. However, the number of days in transit compared to days at the sweet-spots would have been miniscule.
I believe Homo erectus' primary lithic tools were flakes removed from large biface cores that we call handaxes. Flakes removed by hard hammer percussion and edge battering. Battering is obvious on the Boxgrove artifacts, and I suggest that the "rolled" appearance on many handaxes from other sites, which is attributed to fluvial action in the literature, is purposefully battering. I believe Homo erectus had limited manual dexterity and, therefore, held the hammerstone with the tips of his fingers, similar to the method employed by Bob Patten in his backyard. This limited capability with his hands also prevented him from working smaller cores that required the holding hand to apply external support. Finally, it prevented him from deploying a soft hammer of sufficient size and velocity to remove the large flakes associated with the handaxe.
I believe only a few flakes were extracted from a handaxe during a single reduction event. I suspect the core was then discarded more often than it may have been curated. I suggest this because the attempts at refitting the material from Boxgrove (Pope 2004) and Kalambo Falls (Schick 2001:473) have been met with meager to partial results. Never has a complete reduction assemblage from roughout to finished handaxe been demonstrated. Additionally, when I observed the Boxgrove handaxes I was always able to located the site of the last flake removal by the lack of battering. This indicated to me that this flake was extracted and the handaxe was discarded.
The tranchet flake has been called a "finishing flake" because the edge it leaves around the distal end of the handaxe is unbattered. Roe has suggested that this "... outer edge of the resulting scar provides the implement's cutting edge, which is straight and sharp ..." (1981:91). I have found nothing in the literature, such as use wear analysis, that indicates that this tranchet flake scar edge was purposely used. I suggest the tranchet flake was the desired product and the handaxe was discarded upon its removal. Or, the tranchet flake removal was an attempt to rejuvenate the core, similar to what Bob Patten did in his backyard, and the attempt was unsuccessful.
I believe the discarded handaxes were often picked up at a later time and more flakes were extracted from them. If a discarded handaxe had not been exhausted, then it would have been easier to extract flakes from it, than to start over with a new nodule or large flake. This further extraction of flakes doesn't have to be by the same individual, or even in the same generation. For that matter, I suspect some handaxes have seen flake extractions by Homo erectus and subsequently by Homo sapiens. If I am correct about the reuse, or extraction of more flakes, then the handaxe reduction time could be several days, years, or thousands of years. One could argue that the handaxe had a very long use life or many use lives. This idea of discard and later reuse came from my observations of the handaxes from Boxgrove. Some had differential patination on the flake scars. Mike Collins made similar observations for the blade cores from the Gault Clovis site and first introduced me to this concept of use-discard-reuse (2004, February personal communication). The handaxe from Warren Hill at the beginning of this paper has differential patination. See the distal end in the left image.
If this reuse scenario is correct, then I suspect the handaxe was occasionally picked up and expediently used in scraping or other tasks. However, I suspect the proposed limited dexterity of Homo erectus made these types of tasks difficult with these large cores. Smaller flakes would have been much easier for them to manipulate.
In summary, my belief is that the handaxe was a large biface core made by Homo erectus individuals who lacked the manual dexterity of modern humans. I arrived at this conclusion based on the morphology of the handaxe. And, since there is no fossil hand evidence to suggest otherwise, my theory is intact. I am forced to admit that I believe Homo erectus' hand was evolving during its 1.6 million years of existence. Therefore, I would expect there also was an evolution in the handaxe from large to small and thick to thin. Yet, this evolution is only going to be visible in vertically stratified sites or well-dated sites. And, then it will still be difficult to identify because the handaxe was the by-product of expedient flake extraction. It was not the desired product.
For the reader who jumped to this Conclusion to get an abridged version of this paper, you are going to be disappointed. This is not a summary, it is a conclusion.
My interest in the Acheulean handaxe began in February of 2005. The research for this paper began in July and the actual writing started September. I went public with the paper in February of 2006. I am writing this because I want the reader to know this research project has been extremely enjoyable. In fact, I can say it has been one of the most enjoyable things I have done in my lifetime. As a young man, I never would have embarked on a project like this without it being a requirement of my job or schooling. Plus, I know I would have disliked the entire task. I guess this is a sign of my aging.
I did not perform my research in the vacuum of the literature. Many real people have contributed to it. Some sent me to new literature sources. Some introduced me to concepts that I would not have otherwise discovered. Some provided data and others debated with me. Some just offered anecdotes from their experiences. And most interesting, half of them I have never met. The power of the Internet is enormous.
That said, the following is a list of people who have contributed to this research. It is not a list of people who endorse my ideas, because most probably disagree with them. It is a list of people who have their own ideas and beliefs, and who were willing to share them with me. For this I thank them. For the people I might have omitted here, I apologize.
|Aiello, Leslie and Christopher Dean|
|1990  ||An Introduction To Human Evolutionary Anatomy. San Diego: Academic Press, Inc.|
|1992  ||The High Lodge Flint Industries. In High Lodge: Excavations by G. de G. Sieveking, 1962-8, and J. Cook, 1988. edited by Nick Ashton et al. London: British Museum Press. Pp. 124-163.|
|Ashton, Nick and John McNabb|
|1993  ||Bifaces in Perspective. In Stories in Stone, edited by Nick Ashton & Andrew David. London: Lithics Studies Society Occasional Paper No.4. Pp. 182-191.|
|Ashton, Nick and Mark White|
|2003  ||Bifaces and Raw Materials: Flexible Flaking in the British Early Paleolithic. In Multiple Approaches to the Study of Bifacial Technologies. edited by Marie Soressi and Harold L. Dibble. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. Pp. 109-124.|
|2004  ||The Lithic Containers of the Archaeological Record.   http://www.ele.net/containers/lithic_containers.htm.|
|1961  ||Typologie du Paléolithique ancien et moyen. Bordeaux: Mémoires de l'Institut Préhistoriques de l'Université de Bordeaux 1.|
|1968  ||The Old Stone Age. New York: McGraw-Hill Book Company.|
|1979  ||The Basics of Biface Knapping in the Eastern Fluted Point Tradition: A Manual for Flintknappers and Lithic Analysts. 4th edition. Lynchburg: Reprinted in 2000 by Piltdown Productions.|
|Calvin, William H.|
|2002  ||Rediscovery and the Cognitive Aspects of Toolmaking: Lessons from the Handaxe. Behavioral and Brain Sciences 25(3):403-404.|
|Clark, J. Desmond|
|1996  ||Development of Organization, Language, and Social Relationship of the Makers of the Oldowan and Acheulian Industrial Complexes. In The First Humans and Their Cultural Manifestations. Forli: XIII International Congress of Prehistoric and Protohistoric Sciences Forli Italia-8/14 September 1996. Vol 4.|
|Clark, J. Desmond and M. R. Kleindienst|
|2001  ||The Stone Age Cultural Sequence: Terminology, Typology, and Raw Material. In Kalambo Falls Prehistoric Site Vol III The Earlier Cultures: Middle and Earlier Stone Age. edited by J. Desmond Clark. Cambridge: Cambridge University Press. Pp. 34-65.|
|1969  ||World Prehistory: A New Outline: Being the Second Edition of 'World Prehistory'. Cambridge: Cambridge at the University Press.|
|Davidson, Iain and William Noble|
|1993  ||Tools and Language in Human Evolution. In Tools, Language and Cognition. edited by Kathleen Gibson and Tim Ingold. New York: Cambridge University Press. Pp. 363-388.|
|Debenath, Andre and Harold L. Dibble|
|1994  ||Handbook of Paleolithic Typology, Volume One: Lower and Middle Paleolithic of Europe. Philadelphia: University of Pennsylvania.|
|Dibble, Harold L.|
|1989  ||The Implications of Stone Tool Types for the Presence of Language During the Lower and Middle Palaeolithic. In The Human Revolution. Behavioural and Biological Perspectives in the Origins of Modern Humans. edited by P. Mellars and C. Stringer. Edinburgh: Edinburgh University Press. Pp. 415-432.|
|1969  ||An Analysis of the R. O. M. Collection, Lower Paleolithic Implements: Furze Platt, Maidenhead, Berkshite, England. Unpublished paper and notes in the possession of the Tony Baker, the author.|
|1986  ||The Palaeolithic Settlement of Europe. Cambridge: Cambridge University Press.|
|1995  ||Mental Abilities of Early Homo: Elements of Constrain and Choice in Rule Systems. In Modelling the Early Human Mind. edited by P. Mellars & K. Gibson. Cambridge: The McDonald Institute for Archaeologial Research. Pp. 191-215.|
|Gowlett, J.A.J., R.H. Crompton and Li Yu|
|2001  ||Allometric Comparisons Between Acheulean and Sangoan Large Cutting Tools at Kalambo Falls. In Kalambo Falls Prehistoric Site Vol III The Earlier Cultures: Middle and Earlier Stone Age. edited by J. Desmond Clark. Cambridge: Cambridge University Press. Pp. 612-619.|
|1979  ||Palaeolithic Reflections: Lithic Technology and Ethnographic Excavation among Australian Aborigines. New Jersey: Humanities Press Inc, New Jersey.|
|Isaac, Glynn L1.|
|1969  ||Studies of Early Culture in East Africa. World Archaeology 1:1-28.|
|1977  ||Olorgesailie: Archeological Studies of a Middle Pleistocene Lake Basin in Kenya. Chicago: The University of Chicago Press.|
|Johanson, Donald and Blake Edgar|
|1996  ||From Lucy To Language. New York: Simon & Schuster Editions.|
|Keller, Charles M.|
|1973  ||Montagu Cave in Prehistory: A Descriptive Analysis. Berkeley: University of California Anthropological Records Vol.28.|
|2000  ||Review articles: Boxgrove. Antiquity 74:439-441.|
|McPherron, Shannon P.|
|2003  ||Technological and Typological Variability in the Bifaces from Tabun Cave, Israel. In Multiple Approaches to the Study of Bifacial Technologies. edited by Marie Soressi and Harold L. Dibble. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. Pp. 55-76.|
|2005  ||Personal Communications between October and December.|
|Noll, Michael P. and Michael D. Petraglia|
|2003  ||Acheulean Bifaces and Early Human Behavioral Patterns in East Africa and South India. In Multiple Approaches to the Study of Bifacial Technologies. edited by Marie Soressi and Harold L. Dibble. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. Pp. 31-54.|
|1999  ||Old Tools-New Eyes: A primal primer of Flintknapping. Denver: Stone Dagger Publications.|
|2004  ||Behavioural Implications of Biface Discard: Assemblage variability and land-use at the Middle Pleistocene Site of Boxgrove. In Lithics in action: Papers from the Conference Lithic Studies in the Year 2000. edited by Elizabeth A. Walker et al. Oxford: Lithic Studies Society/Oxbow Books. Pp. 39-46.|
|Roe, Derek A.|
|1967  ||A Study of Handaxe Groups of The British Lower and Middle Palaeolothic Periods, using Methods of Metrical and Statistical Analysis, with a Gazetteer of British Lower and Middle Palaeolithic sites. Ph.D. Dissertation, University of Cambridge.|
|1968  ||British Lower and Middle Palaeolithic Handaxe Groups. Proceedings of the Prehistoric Society 34:1-82.|
|1981  ||The Lower and Middle Palaeolithic Periods in Britian. London: Routledge & Kegan Paul Ltd.|
|2001  ||The Kalambo Falls Large Cutting Tools: A Comparative Metrical and Statistical Analysis. In Kalambo Falls Prehistoric Site Vol III The Earlier Cultures: Middle and Earlier Stone Age. edited by J. Desmond Clark. Cambridge: Cambridge University Press. Pp. 492-599.|
|2003  ||An Overview, with Some Thoughts on the Study of Bifaces. In Multiple Approaches to the Study of Bifacial Technologies. edited by Marie Soressi and Harold L. Dibble. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. Pp. 273-285.|
|Schick, Kathy D.|
|2001  ||An Examination of Kalambo Falls Acheulean Site B5 from a Geoarchaeological Perspective. In Kalambo Falls Prehistoric Site Vol III The Earlier Cultures: Middle and Earlier Stone Age. edited by J. Desmond Clark. Cambridge: Cambridge University Press. Pp. 463-480.|
|Schick, Kathy D. and J. Desmond Clark|
|2003  ||Biface Technology Development and Variability in the Acheulean Industrial Complex in the Middle Awash Region of the Afar Rift, Ethiopia. In Multiple Approaches to the Study of Bifacial Technologies. edited by Marie Soressi and Harold L. Dibble. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. Pp. 1-30.|
|Whittaker, John C.|
|1994  ||Flintknapping: Making & Understanding Stone Tools. Austin: University of Texas Press.|
|1988  ||Petrography of the Lower Palaeolithic Tool Assemblage of the Caune de l'Arago (France). World Archaeology 19:376-387.|
|2002  ||Archaeology and Cognitive Evolution. Behavioral and Brain Science 25(3):389-402.|