Drimolen Main Quarry Research Articles

Technology or taphonomy? A study of the 2.04–1.95 Ma bone tools from Drimolen Main Quarry, South Africa

Analysis of 124 rounded fossils, potential bone tools, from the 2.04–1.95 Ma early hominin-bearing Drimolen Main Quarry palaeocave deposits in South Africa were subject to comparative analysis of fossil and bone collections with known taphonomic accumulator/s, actualistic experiments, and comparative analysis relative to published data in the taphonomic literature. From this sample, 51 specimens were identified as bone tools. The inclusion of these specimens raises the number of bone tools identified at Drimolen Main Quarry to 65. The bone tools have a rounded tip and an associated use-wear pattern that is restricted to, and radiates from, this rounded tip. Diaphyseal fragments were the most common raw material selected for tool use. We hypothesise that the raw material was collected from both carnivore kill and natural death sites. The striation patterns, identified though visual comparisons, present on the bone tools comprise parallel, subparallel and diagonal striations which suggests that the tools may have had a multi-use application. The place of bone technology within the South African Earlier Stone Age is also discussed.

New hominin dental remains from the ∼2.04–1.95 Ma Drimolen Main Quarry, South Africa

Background The Drimolen Palaeocave site is situated within the UNESCO Fossil Hominid Sites of South Africa World Heritage Area and has yielded numerous hominin fossils since its discovery in 1992. Most of these fossils are represented by isolated dental elements, which have been attributed to either of two distinct hominin genera, Paranthropus and Homo. Aim This paper provides morphological descriptions for a further 19 specimens that have been recovered from the ∼2.04–1.95 Ma Drimolen Main Quarry (DMQ) deposits since 2008. This paper also discusses the two primary hypotheses used to explain Paranthropus robustus variation: sexual dimorphism, and micro-evolution within a lineage. Subjects and methods These 19 fossils are represented by 47 dental elements and expand the sample of DMQ early Homo from 13 to 15, and the sample of Paranthropus robustus from 69 to 84. Results The evidence presented in this paper was found to be inconsistent with the sexual dimorphism hypothesis. Conclusion Some support was found for the micro-evolution hypothesis.

New hominin dental remains from the Drimolen Main Quarry, South Africa (1999–2008)

AbstractObjectivesTwenty‐four dental specimens from the Drimolen Main Quarry (DMQ) are described. This increases the number of DMQ Paranthropus robustus specimens from 48 to 63 and DMQ Homo specimens from 8 to 12. This allows reassessment of the proposed differences between the DMQ P. robustus assemblage and that of Swartkrans. Analysis conducted assesses intraspecific and inter‐locality variation.Materials and MethodsWe examined the P. robustus and early Homo assemblages from South Africa. Morphology was observed using a hand lens and a binocular microscope. Mesiodistal and buccolingual measurements were taken using plastic‐tipped calipers. Summary statistics were generated and patterns of variability in P. robustus were assessed through box plots and Mann–Whitney U tests.ResultsComparison between the expanded DMQ and Swartkrans P. robustus assemblages demonstrates overlap in size. Ten dental variables show statistically significant differences.DiscussionThe expanded P. robustus sample allowed us to re‐examine previous analyses of differences in tooth size between the samples. While analyses presented here show a high degree of overlap in the MD and BL dimensions of the two assemblages, significant differences were found in the mean values of these variables in the postcanine maxillary teeth—consistent with previous analyses. Two current hypotheses may explain this pattern: 1) dental size increase through the P. robustus lineage or 2) different sample composition between the two sites. Small sample sizes for all permanent dental classes in the DMQ assemblage represents a limitation on this analysis and interpretations thereof. Any addition to the DMQ or the Swartkrans samples may alter these results.

Complexities of assessing palaeocave stratigraphy: reconstructing site formation of the ∼2.61 Ma Drimolen Makondo fossil site.

Palaeocave sites in South Africa are world renowned repositories for palaeontological and archaeological material, dating from the terminal Pliocene to the Early Pleistocene. Due to their antiquity, complex karstification history and multifaceted infilling phases, palaeocave sites are notoriously difficult to contextualise. Further to this, 19th century lime-mining and diverse excavation and sampling techniques, have complicated stratigraphic interpretations of fossil-bearing deposits within the region. Locating and assessing newly discovered, minimally disturbed palaeocave sites allow for contextual information to be gathered with greater confidence and can aid in constructing a more robust understanding of the South African fossil record. Here, we use Drimolen Makondo; a minimally lime-mined ∼2.61 Ma palaeontological site, to apply a series of in-depth stratigraphic and micromorphological studies. Contextual data presented within this study, testifies to a relatively rapid infill with greater fluvial activity when compared to adjacent deposits at the younger ∼2.04–1.95 Ma Drimolen Main Quarry. The quantity of articulated macromammalian remains, high density of micromammalian remains and pollen identified, also highlights Drimolen Makondo as a key site for ongoing palaeoenvironmental studies at the Pliocene to Pleistocene transition in South Africa.

Drimolen cranium DNH 155 documents microevolution in an early hominin species.

Paranthropus robustus is a small-brained extinct hominin from South Africa characterized by derived, robust craniodental morphology. The most complete known skull of this species is DNH 7 from Drimolen Main Quarry, which differs from P. robustus specimens recovered elsewhere in ways attributed to sexual dimorphism. Here, we describe a new fossil specimen from Drimolen Main Quarry, dated from approximately 2.04-1.95 million years ago, that challenges this view. DNH 155 is a well-preserved adult male cranium that shares with DNH 7 a suite of primitive and derived features unlike those seen in adult P. robustus specimens from other chronologically younger deposits. This refutes existing hypotheses linking sexual dimorphism, ontogeny and social behaviour within this taxon, and clarifies hypotheses concerning hominin phylogeny. We document small-scale morphological changes in P. robustus associated with ecological change within a short time frame and restricted geography. This represents the most highly resolved evidence yet of microevolutionary change within an early hominin species.

Contemporaneity of Australopithecus, Paranthropus, and early Homo erectus in South Africa.

Understanding the extinction of Australopithecus and origins of Paranthropus and Homo in South Africa has been hampered by the perceived complex geological context of hominin fossils, poor chronological resolution, and a lack of well-preserved early Homo specimens. We describe, date, and contextualize the discovery of two hominin crania from Drimolen Main Quarry in South Africa. At ~2.04 million to 1.95 million years old, DNH 152 represents the earliest definitive occurrence of Paranthropus robustus, and DNH 134 represents the earliest occurrence of a cranium with clear affinities to Homo erectus These crania also show that Homo, Paranthropus, and Australopithecus were contemporaneous at ~2 million years ago. This high taxonomic diversity is also reflected in non-hominin species and provides evidence of endemic evolution and dispersal during a period of climatic variability.

The first bone tools from Kromdraai and stone tools from Drimolen, and the place of bone tools in the South African Earlier Stone Age

An apparently unique part of the Earlier Stone Age record of Africa are a series of bone tools dated to between ∼2 and ∼1 Ma from the sites of Olduvai in East Africa, and Swartkrans, Drimolen and Sterkfontein in South Africa. The South and East African bone tools are quite different, with the South African tools having a number of distinct characters formed through utilisation, whereas the East African tools are flaked tools that in some cases mirror stone tool production. The South African bone tools currently consists of 108 specimens from the three sites above. They have been interpreted as being used for digging into homogenous grained soil to access high quality food resources, or as a multi-purpose tools. It has generally been assumed that they were made by Paranthropus robustus, as this species is most often associated with bone tool bearing deposits, especially when high numbers occur. However, early Homo is also found at these sites. Here we report on two fossils from the Paranthopus robustus site of Kromdraai B, which has only yielded one stone tool to date, that have the same characteristic wear patterns as the bone tools identified at other sites. We also describe a small collection (N = 6) of the first stone tools recovered from the bone tool and Paranthropus and early Homo bearing site of Drimolen Main Quarry. These discoveries further increase the association between bone and stone tool technologies in the South African Earlier Stone Age. However, there remains no direct correlation between the occurrence of bone or stone tools and a particular species being found at the different sites. We then review the place of these bone tools within the South African archaeological record. They appear to be a consistent part of the South African record for around a million years or so between <∼2.3 and >∼0.8 Ma. While they change little over this time, they occur with both Oldowan and Acheulian assemblages.

Visualising scales of process: Multi-scalar geoarchaeological investigations of microstratigraphy and diagenesis at hominin bearing sites in South African karst

Multi-scalar geoarchaeological investigations were conducted on several samples of sediment (dolomite cave sediments, ferricrete ridge, speleothem, tufa and tufa cave sediments) from four early hominin fossil-bearing sites (Taung Type Site, Haasgat, Drimolen Main Quarry, Elandsfontein) in different South African karst environments. The study was designed to test the value of geoarchaeological techniques for identifying and characterising environments of deposition and diagenetic processes involved in site formation within different mediums and different karst environments. The traditional petrographic method is weighed against two relatively new methodological contributions to site formation and diagenesis: Computed Tomography (CT) and automated Quantitative Evaluation of Minerals using Energy Dispersive Spectroscopy (QEM-EDS), employing QEMSCAN® technology. An integrated micro-sampling approach is outlined for successful cross-correlation between techniques. The study demonstrates that different analyses vary in their ability to visualise different types of process – primary and secondary. Thin section petrography remains the ‘gold standard’ for analyses conducted at the micro-scale, while QEM-EDS and CT offer exciting potential to perform meso-scale analyses and are best utilised as complementary rather than alternative techniques to petrography.