Functional insights into the innovative Early Howiesons Poort technology at Diepkloof Rock Shelter (Western Cape,South Africa)

The Howiesons Poort (‘HP’) is characterized by a set of technological innovations that mark a rupture in the Southern African Middle Stone Age. However perspectives regarding its origin and emergence remain speculative. The recent identification of an Early HP phase at Diepkloof Rock Shelter provides the opportunity to characterize the initial stage of this technology and to discuss various mechanisms behind its innovative characteristics.     

Hunting with Howiesons Poort segments: pilot experimental study and the functional interpretation of archaeological tools

For many decades the use of backed pieces from the Howiesons Poort, between about 70 ka and 55 ka ago, in South Africa has been a point of discussion. Recently direct evidence has been provided to associate these tools with Middle Stone Age hunting strategies. Yet, whether they were used to tip hunting weapons or as barbs remained an open question. In this paper we introduce a set of pilot experiments designed to test the effectiveness of Howiesons Poort segments, the type fossils of the industry, hafted in four different configurations as tips for hunting weapons. It is shown that the morphological type can be used successfully in this way. We present the results of a macrofracture analysis conducted on the experimental tools and compare these to results obtained from three Howiesons Poort backed tool samples. By correlating experimental outcomes, macrofracture data and the interpretation of micro-residue distribution patterns, we provide some insight into the functional variables that might be associated with Howiesons Poort segments.     

Middle Stone Age bone tools from the Howiesons Poort layers,Sibudu Cave,South Africa

Recently discovered bone implements from Middle Stone Age (MSA) deposits at Sibudu Cave, South Africa, confirm the existence of a bone tool industry for the Howiesons Poort (HP) technocomplex. Previously, an isolated bone point from Klasies River provided inconclusive evidence. This paper describes three bone tools: two points and the end of a polished spatula-shaped piece, from unequivocal HP layers at Sibudu Cave (with ages greater than ∼61 ka). Comparative microscopic and morphometric analysis of the Sibudu specimens together with bone tools from southern African Middle and Later Stone Age (LSA) deposits, an Iron Age occupation, nineteenth century Bushman hunter-gatherer toolkits, and bone tools used experimentally in a variety of tasks, reveals that the Sibudu polished piece has use-wear reminiscent of that on bones experimentally used to work animal hides. A slender point is consistent with a pin or needle-like implement, while a larger point, reminiscent of the single specimen from Peers Cave, parallels large un-poisoned bone arrow points from LSA, Iron Age and historical Bushman sites. Additional support for the Sibudu point having served as an arrow tip comes from backed lithics in the HP compatible with this use, and the recovery of older, larger bone and lithic points from Blombos Cave, interpreted as spear heads. If the bone point from the HP layers at Sibudu Cave is substantiated by future discoveries, this will push back the origin of bow and bone arrow technology by at least 20,000 years, and corroborate arguments in favour of the hypothesis that crucial technological innovations took place during the MSA in Africa.     

A Segment is not a Monolith: evidence from the Howiesons Poort of Sibudu,South Africa

Segments from the Howiesons Poort of Sibudu, South Africa, can be separated into at least three populations based on quartz, hornfels and dolerite rocks used for their production. Length, breadth, thickness and tip cross-sectional areas are significantly different between segments made on the three rock types. Segments are not monoliths, and they were not intended as a single tool type, they were flexible enough to be mounted to shafts in a variety of ways. Several hafting strategies are evident, including the use of different adhesive recipes. Most segments were probably parts of hunting weapons, based on use trace analysis, but weapon types varied. Quartz segments have standardized shapes (short and deep), perhaps because they were hafted as transverse arrowheads. While hornfels and dolerite segments may on occasion also have been parts of projectiles, the large dolerite segments could sometimes have served as parts of spearheads, with two segments hafted back-to-back. Howiesons Poort segment technology is sophisticated; its makers appreciated distinct properties of rocks, their flaking, wear and impact possibilities. Further, they recognized the best sizes and shapes for use with each kind of weapon, they understood the qualities and applications of various adhesive recipes, and they knew how to make a variety of hafts from materials that included bone and wood.     

Quartz-tipped arrows older than 60 ka: further use-trace evidence from Sibudu,KwaZulu-Natal,South Africa

This paper discusses the results of a detailed functional study of 16 microlithic backed tools made on quartz, and newly excavated at Sibudu Cave, KwaZulu-Natal, South Africa. The layers associated with the artefacts have OSL ages of 61.7 ± 1.5 ka, 63.8 ± 2.5 ka and 64.7 ± 1.9 ka and represent the Howiesons Poort Industry at the site. I show that more than 50% of the pieces could hardly have been used in any way other than to tip arrows in a transverse position. This outcome supports previous inferences that some of these small stone tools, and perhaps a bone point from the same context, signify the use of bow and arrow technology during the Middle Stone Age. In addition to transversely hafted arrow tips, there is also evidence that some of the tools could have been hafted diagonally. Such tools could have been used equally successfully as arrow tips or barbs, or as barbs for hand-delivered spears. The variation in hafting configuration for these geometric shapes signifies hunting technologies that were flexible and most likely adapted according to need, preference, season and/or prey type.     

Blade technology and tool forms in the Middle Stone Age of South Africa: the Howiesons Poort and post-Howiesons Poort at Rose Cottage Cave

It has been suggested that between 80 and 35 ka the Middle Stone Age record of South Africa reveals episodes of inventiveness and innovation, punctuated by apparent returns to more conventional technologies. One such episode is the Howiesons Poort (HP). The appearance of a range of small geometric forms, apparently used as insets in multi-component tools, has been considered as evidence of improved hunting weapons, with possible social and symbolic connotations. On the basis of evidence such as backed tool production, small blade technology, the occurrence of typical end-scrapers and burins similar to those encountered in the European Upper Paleolithic, long-distance transport of fine-grained raw materials, and non-lithic novelties, the HP is associated with increased levels of technological efficiency and with behavioral innovations that could have allowed the expansion of African populations to other regions. Yet our knowledge of HP technology and tool production is limited to the analysis of Klasies River Main site by Singer and Wymer and Sarah Wurz, and a few preliminary reports from other sites. This is why we present here a detailed technological and typological analysis of several HP and post-HP assemblages from the well-excavated, well-dated and well-stratified site of Rose Cottage. Our analysis shows: (a) that the HP blade production was a real technical innovation, but was not based on indirect percussion, as often suggested; (b) that blade production was based on the use of marginal percussion which does not occur in the blade production of the Eurasian Middle Paleolithic; (c) that the tool kit was dominated by backed pieces, but not all can be considered as hunting weapons; (d) that neither end-scrapers nor burins are typical of this industry and are no more an antecedent to the European Upper Paleolithic than the end-scrapers and burins of the Middle Paleolithic; (e) that patterns of raw material procurement do not conform to models based on evidence from Klasies; (f) that diachronic changes within the Rose Cottage sequence indicate slow, gradual abandonment of the technological style of the HP; (g) that the post-HP assemblages are of MSA character and are typologically and technologically quite similar to the European Middle Paleolithic; (h) that the lack of persistence of the HP innovations is in need of an explanation. The HP is not a monolithic entity. Implications for the symbolic interpretations of the HP phenomenon are discussed.     

Middle Stone Age pièces esquillées from Sibudu Cave,South Africa: an initial micro-residue study

In this paper I present the results of a micro-residue study conducted on ten pièces esquillées (scaled pieces) from Sibudu Cave, South Africa. These artefacts are associated with the Howiesons Poort Industry (∼61.7 and ∼64.7 ka years ago at Sibudu), representing part of the later phase of the Middle Stone Age. Until now, it was unclear on what these pieces were used, and whether they were functional. Previous experimental use-wear work tentatively pointed towards bone processing. However, replication work on stone tool production technology suggests that pièces esquillées are merely the by/end-product of bipolar knapping. I used residue analysis on the Sibudu artefacts because this alternative method has the potential to identify if they were used, and if so, illuminate the specific materials the pieces were used on. Although the sample is small, all the pièces esquillées reveal a clear animal processing signal. There are some bone deposits on the utilised edges that may substantiate bone processing, or perhaps a bone hammer was used with them, but additional study, including Later Stone Age artefacts, is needed to assess the feasibility of these observations. It remains possible that the artefacts are core reduced pieces that were subsequently used as tools or simply knapped with a bone hammer.     

First molecular identification of a hafting adhesive in the Late Howiesons Poort at Diepkloof Rock Shelter (Western Cape,South Africa)

The hafting of tools using adhesive is one of the innovative features that characterizes the southern African Middle Stone Age. This technology has mainstream implications but remains insufficiently documented, largely due to unequal organic preservation and non-adapted analytical procedures. A notable exception is provided by the recent results from the site of Sibudu (Lombard, 2006; Wadley et al., 2009).     

Nature and significance of the Howiesons Poort to post-Howiesons Poort transition at Klein Kliphuis rockshelter,South Africa

This paper considers the transition from Howiesons Poort to post-Howiesons Poort technologies at the rock shelter site of Klein Kliphuis, South Africa. The transition at this site is shown to be gradual, with incremental changes in material selection and in the size and shapes of flakes and cores. Implements which appear to blend characteristics of those distinctive of the earlier and later industries appear briefly at the mid-point of the transition. The results suggest that there is unlikely to have been an occupational hiatus between the Howiesons Poort and post-Howiesons Poort. Explanations for the Howiesons Poort phrased in terms of population expansion and contraction are also difficult to support. Technological changes at this time may relate to environmental variation, though the limited nature of terrestrial archives documenting changes in resource productivity necessitate that any such suggestion be made with caution.     

The context,form and significance of the MSA engraved ostrich eggshell collection from Diepkloof Rock Shelter,Western Cape,South Africa

Broken ostrich eggshells are commonly found in Middle Stone Age sites of southern Africa, presumably collected for food consumption, and later used as artefacts. At Diepkloof Rock Shelter, Middle Stone Age inhabitants used ostrich eggshells as a medium to convey abstract depictions. Since 1998, excavations at Diepkloof have recovered 408 engraved pieces of ostrich eggshells. The study of these shows that Diepkloof inhabitants applied a restricted set of geometric engraving patterns, with the dominance of 2 main motifs, one using a hatched band and the other sub-parallel to converging lines. These motifs coexisted, but shifted in frequency toward the latter through time. Together with evidence that ostrich eggshells were used as containers, these patterns support the hypothesis that engravings were made with respect to clear but flexible social conventions and were part of a complex system of visual and symbolic communication. Since our last report (Texier et al., 2010), a few engraved pieces have been found in lower stratigraphic units, expanding substantially the time-range of the engraving practice on ostrich eggshells at Diepkloof. The earliest engravings appear at the end of the Early Howiesons Poort phase, but become numerous only during the Intermediate and Late phases of the Howiesons Poort. The collection from Diepkloof is presently unique and likely underlines the existence of regional traditions within the Howiesons Poort. Interestingly, and significantly in our view, the engraving disappears at the same time as the Howiesons Poort technology. We argue that this disappearance may reflect a modification in the way late Middle Stone Age inhabitants interacted with one another.     

New ages for the post-Howiesons Poort,late and final Middle Stone Age at Sibudu,South Africa

Optically stimulated luminescence (OSL) measurements are reported for single grains of quartz from deposits within Sibudu rock shelter. Such measurements enable rejection of unrepresentative grains and application of the finite mixture and central age models to obtain the most reliable age estimates. Three types of single-grain equivalent dose (D_e) distributions were observed: one sample represented a single dose population, three samples indicated mixing between Iron Age (IA) and Middle Stone Age (MSA) deposits, and 10 samples (in addition to the three mixed samples) showed scattered distributions. The latter type resulted from differences in the beta dose received by individual grains. For these samples, the beta doses were modelled and adjusted accordingly. Ages for the 14 samples collected from MSA deposits post-dating the Howiesons Poort (HP) resulted in three age clusters, which are stratigraphically consistent with the three informally named cultural phases at Sibudu: namely, the post-HP, late MSA and final MSA. Weighted mean ages of 58.5 ± 1.4 ka, 47.7 ± 1.4 ka and 38.6 ± 1.9 ka were calculated for these phases, respectively. The three phases were separated by two occupational hiatuses with durations of 10.8 ± 1.3 ka and 9.1 ± 3.6 ka. We hypothesise that the punctuated presence of humans at Sibudu was determined by large-scale fluctuations in climate during oxygen isotope stage (OIS) 3, which resulted in alternating wet and dry periods. Phases of occupation correspond to wet periods when fresh water was available in the Tongati River, whereas intervals of site abandonment correspond to dry periods when people were forced to migrate in search of a reliable source of fresh water. Where people migrated to, remains unresolved.     

An experimental micromorphological investigation of bedding construction in the Middle Stone Age of Sibudu,South Africa

We conducted experiments to compare the micromorphological signatures of modern burnt sedge and grass bedding to laminated layers of carbonized material and phytoliths in Middle Stone Age deposits at the shelter, Sibudu. The experiments were designed to clarify the formation processes associated with the laminated layers and to investigate whether these previously identified layers of bedding were deliberately burned or not. The results indicate that the laminated layers were most likely produced by human activity related to the construction, maintenance and burning of bedding. Furthermore, our experiments demonstrate that large volumes of vegetal material could have produced the relatively thin, archaeological deposits of burnt bedding.     

Possible shell beads from the Middle Stone Age layers of Sibudu Cave,South Africa

Recent excavations at Sibudu Cave, KwaZulu-Natal, South Africa, uncovered an Iron Age horizon below which is a complex 3 m thick Middle Stone Age sequence with post-Howiesons Poort, Howiesons Poort, Still Bay and pre-Still Bay layers. Available OSL ages indicate that the Howiesons Poort occupation is older than 60 ky and the Still Bay older than 70 ky. Here we present the archaeological context and the taphonomic analysis of six Afrolittorina africana, three of which bear perforations, from the Still Bay and Howiesons Poort layers of this site. The single specimen from the latter cultural horizon comes from the lowermost layer attributed to this technocomplex. This and the depositional context of this layer suggest that this shell derives, as do the other five, from the Still Bay occupation layers. Taphonomic analysis of the archaeological specimens based on present day Afrolittorina africana biocoenoses, microscopic examination, morphometry, experimental perforation of modern shells, and a review of the natural agents that may accumulate marine shells at inland sites, indicate probable human involvement in the collection, transport, modification, and abandonment of Afrolittorina africana in Sibudu. If confirmed by future discoveries these shells would corroborate the use of personal ornaments, already attested at Blombos Cave, Western Cape Province, by Still Bay populations. The apparent absence of ornaments at Howiesons Poort sites raises the question of the mechanisms that have led to cultural modernity since it seems to contradict the scenario according to which cultural innovations recorded at Middle Stone Age sites reflect a process of continuous accretion and elaboration interpreted as the behavioural corollary of the emergence of anatomically modern humans.     

OSL and TL dating of the Middle Stone Age sequence at Diepkloof Rock Shelter (South Africa): a clarification

Diepkloof Rock Shelter offers an exceptional opportunity to study the onset and evolution of both Still Bay (SB) and Howiesons Poort (HP) techno-complexes. However, previous age estimates based on luminescence dating of burnt quartzites (Tribolo et al., 2009) and of sediments (Jacobs et al., 2008) were not in agreement. Here, we present new luminescence ages for 17 rock samples (equivalent dose estimated with a SAR-ITL protocol instead of classical MAAD-TL) as well as for 5 sediment samples (equivalent dose estimated with SAR-single grain OSL protocol) and an update of the 22 previous age estimates for burnt lithics (modified calibration and beta dose estimates). While a good agreement between the rock and sediment ages is obtained, these estimates are still significantly older than those reported by Jacobs et al. (2008). After our own analyses of the sediment from Diepkloof, it is suspected that these authors did not correctly chose the parameters for the equivalent dose determination, leading to an underestimate of the equivalent doses, and thus of the ages.     

The evolution of human culture during the later Pleistocene: Using fauna to test models on the emergence and nature of “modern” human behavior

It has often been argued that the success and spread of modern humans ∼50,000 years ago was due to a series of key behavioral shifts that conferred particular adaptive advantages. And yet, particularly during the African Middle Stone Age (MSA), some of these “modern” behaviors see only patchy expression across time and space. Recent models have proposed a link between the emergence of modern behaviors and environmental degradation and/or demographic stress. Under these models, modern behaviors represent a form of social/economic intensification in response to stress; if this were the case, signs of subsistence intensification should be more common during periods in which these behaviors are manifested than when they are not. In order to test these models, I analyzed faunal remains from Sibudu Cave (South Africa), focusing on the Howieson’s Poort (HP), a phase in which modern behaviors are evidenced, and the post-HP MSA, when classical signatures of such behavior have disappeared. Significant variability in hunting behavior was identified. While much of this variability appears to correspond with changes in the local environment, evidence for resource stress was more common during the HP. The implications of these results to our understanding of the evolution of human culture are discussed.     

Behavioral ecological models of lithic technological change during the later Middle Stone Age of South Africa

This paper examines changes in the organization of lithic technological systems during the later Middle Stone Age (MSA) of South Africa. Using principal components analysis (PCA), the study looks at the lithic data from two important South African MSA sites: Blombos Cave and Klasies River Mouth. The paper uses PCA to describe the transition to (1) the biface-dominated Still Bay industry at Blombos Cave and (2) the microlithic Howiesons Poort industry at Klasies River Mouth. Based on these analyses, the paper offers a synthetic scenario of the emergence of the Still Bay industry from earlier MSA industries, closely followed by the dramatic transition to the Howiesons Poort. Using a few principles of tool design and behavioral ecological models derived from the study of modern foragers, the paper suggests that the Still Bay came about as the result of deteriorating environmental conditions at the beginning of Oxygen Isotope Stage 4, which caused resources to become scarce and more widely distributed. The study proposes that the bifacial point strategy of the Still Bay was a response to wider mobility patterns and increased movement away from lithic raw material sources. The paper then suggests that Howiesons Poort emerged as information sharing strategies improved, and resources in the environment could be more efficiently targeted with more task-specific tools. The paper closes by reviewing the implications of these findings for modern human origins in South Africa.     

South African palaeoenvironments during marine oxygen isotope stage 4: a context for the Howiesons Poort and Still Bay industries

Spanning the period from ∼74–58 ka, and being broadly coeval with marine oxygen isotope stage 4 (MIS 4), the Still Bay and Howiesons Poort industries represent important phases in the development of the material culture of early modern humans. How and why these industries occurred when they did, however, remain matters for speculation. A key element of this debate has been the question of what role environmental change during the early stages of the last glacial period may have had on influencing human activity. Unfortunately, well-dated palaeoenvironmental evidence from this period is limited, and the debate has, out of necessity, been driven by the application of conceptual models of environmental change, many of which associate colder and warmer global climates with increased aridity and humidity respectively. In this paper, the regional marine and terrestrial evidence is synthesised to create an evidence-based palaeoenvironmental context. Based on the information available to date, it appears that rather than being characterised by dry conditions, MIS 4 was a period of relatively cool, moist climates, the ubiquity of which transcends the modern regional climate boundaries. It is suggested that orbital parameters at this time created greater interaction between tropical and temperate circulation systems, bringing more moisture to the subcontinent. These findings highlight the distinct nature of southern African climate systems, and caution against the application extra-regional conceptual models or inferring linear relationships with polar records.     

Technological successions in the Middle Stone Age sequence of Diepkloof Rock Shelter,Western Cape,South Africa

The southern African MSA comprises a series of phases of unique technological innovations that fuel current models on the evolutionary processes of Anatomically Modern Humans. However, the nature and variability of these technological phases remain poorly documented. This study reports on the previously unpublished sequence of Diepkloof Rock Shelter (South Africa) and investigates the main technological changes therein, particularly emphasizing the emergence, succession and disappearance of the Still Bay (SB) and the Howiesons Poort (HP). We argue for technological change that occurred at different rates and under the influence of variable driving factors. Our model implies that the SB and the HP are not related to the influx of new populations but have regionally specific origins. Unlike the other techno-complexes, the HP at Diepkloof is subdivided into different phases (Early, Intermediate and Late) but only the upper phases resemble the so-called “classic” HP. Finally, the technological sequence of Diepkloof questions the homogeneous picture which has been so far assumed for the southern African MSA and places emphasis on the importance of exploring long regional sequences.     

Bedding, hearths, and site maintenance in the Middle Stone Age of Sibudu Cave, KwaZulu-Natal, South Africa

Micromorphological analysis of sediments from the Middle Stone Age site of Sibudu Cave, KwaZulu-Natal, South Africa, provides a high-resolution sequence and evidence of site formation processes of predominantly anthropogenic deposits. This methodology allows for a detailed interpretation of individual anthropogenic activities, including the construction of hearths and bedding and the maintenance of occupational surfaces through the sweep out of hearths and the repeated burning of bedding. This analysis also provides a context for evaluating other studies at the site relating to magnetic susceptibility, paleobotany, paleozoology, anthracology, and studies of ochre.     

Early evidence of complexity in lithic economy: core-axe production,hafting and use at Late Middle Pleistocene site 8-B-11, Sai Island (Sudan)

Wear analysis indicates that Sangoan core-axes from site 8-B-11 at Sai Island, Sudan, were used while hafted. The middle Sangoan occupation level at 8-B-11 served as a locale where specialized activities were performed, including core-axe manufacture and hafting. Newly manufactured quartz core-axes served as replacements for exhausted items that were mostly fabricated out of raw materials other than quartz, which were carried back to the site in their hafts for re-tooling. The hafted core-axes appear as highly mobile, curated tools, being transported across a large territory. The evidence indicates that the Sangoan is the archaeological reflection of a complex behavioural system involving economic specialization, which appeared in this part of Africa for the first time around 200 ka ago.