A critique of the chronometric evidence for hominid fossils: I. Africa and the Near East 500-50 ka

The chronometric dating evidence for all hominid fossils from Africa and the Near East that have previously been dated to 500-50 ka is critically assessed using the concept of chronometric hygiene, and these dates are revised using Bayesian statistical analyses where possible. Sixteen relevant hominid sites lacking chronometric evidence are briefly discussed. Chronometric evidence from 37 sites is assessed in detail. The dates for many hominid fossils are poorly constrained, with a number dated by comparisons of faunal assemblages-a method that does not have good chronological resolution for much of the last million years. For sites with stratigraphic sequences of dates, it is generally possible to refine the dating, but in some cases, the revised chronology is less precise than previous chronologies. Fossils over 200 ka in age tend to be poorly dated, but for the last 200 kyr, dating is better due to the availability of electron-spin-resonance and thermoluminescence dating. Consideration of the chronologies favored by the proponents of the out-of-Africa and multiregional hypotheses of human evolution shows their selectivity. The chronological assessment of the fossils here is compatible with either hypothesis. If evolutionary schemes that do not rely on the morphology of the hominid fossils to decide the sequence of fossils are to be built, then further dating is required, alongside full publication of existing dates.     

The biological and chronological maturation of early hominids

Recent studies on the rate and pattern of dental development indicate that the growth and maturation of early hominids were more similar to the extant apes than to modern humans. This contrasts with the previously held opinion derived from combined dental development, pattern and attrition studies claiming that early hominids were more hominine in their development (Mann, 1975). This paper explores the origin of this difference of opinion and reviews immature hominid dentitions with the benefit of improved radiographs and new data on the pattern and rate of pongid dental development. Paranthropus and Australopithecus specimens are shown to possess an ape-like development pattern but incisor development is specialized in the former and superficially human-like in pattern. The present and recent studies on dental development rate and pattern justify the position that early hominids were more ape-like in their growth and development. Therefore, ages at death calculated from pongid dental development schedules are provided for most immature early hominids. More detailed studies of early hominid developmental biology are now possible. It is suggested that divergent heterochronic processes characterize changes in brain/body proportions during hominid evolution. Relative rates of bone remodeling processes can now be identified on early hominid skeletons. The paleodemographic analysis of early hominids is little changed by the developmental model one chooses.     

On the fallacy of using orthogenetic models of rectilinear change in arvicolid teeth for estimating the age of the first human settlements in Western Europe

Lozano-Fernández et al. (Lozano-Fernández I, Blain HA, López-García JM, Agustí J. 2014. Biochronology of the first hominid remains in Europe using the vole Mimomys savini: Fuente Nueva 3 and Barranco León D, Guadix-Baza Basin, south-eastern Spain. Hist Biol: Int J Paleobiol. doi:10.1080/08912963.2014.920015) recently published age estimates for two Late Villafranchian sites of Orce (Guadix-Baza basin, SE Spain), BL-D and FN-3, which provide some of the earliest evidence of human presence in Western Europe. The estimates were obtained from mean Lm1 values of the water vole Mimomys savini preserved in the sites and a couple of rectilinear equations derived in the Atapuerca TD section for site age on tooth length. However, this chronometric tool has problems that discourage its use in biostratigraphy, including: (1) the assumption of an orthogenetic trend of Lm1 increase during the evolution of the M. savini/Arvicola lineage; (2) the use of a chronology for the TD section not supported by original ESR data; (3) the discrepancies between the mean Lm1 values published for the TD levels and (4) the chronological ranges predicted when the standard deviations are used, which are exceedingly large as to be of value for biostratigraphic purposes. As a result, the pseudo numerical ages estimated for the Orce sites only add noise to the timing of the first human dispersal in Europe, which is based on a combination of results from well-established techniques such as palaeomagnetism, biostratigraphy and ESR.     

Pliocene hominid partial mandible from Tabarin, Baringo, Kenya

Sediments in the Tugen Hills, west of Lake Baringo, Kenya, form one of the best fossiliferous successions known in Africa spanning the period from 14 my to less than 4 my. Hominoid fossils have previously been recovered from a number of localities in the region. We describe here a new hominid mandible (KNM-TH 13150) from the site of Tabarin, in the Chemeron Formation. Isotopic determinations on a tuff below the fossiliferous horizon gives dates of 4.96 my and 5.25 my. The associated fauna is consistent with these results and independently suggests a minimum age for the specimen of 4.15 my. Although fragmentary, the preserved morphology of the Tabarin mandible is consistent with the diagnosis of the Pliocene hominid Australopithecus afarensis. It can be distinguished from all other currently recognized hominoid taxa.     

Femur length,body mass,and stature estimates of <Emphasis Type="Italic">Orrorin tugenensis</Emphasis>, a 6 Ma hominid from Kenya

To understand the palaeobiology of extinct hominids it is useful to estimate their body mass and stature. Although many species of early hominid are poorly preserved, it is occasionally possible to calculate these characteristics by comparison with different extant groups, by use of regression analysis. Calculated body masses and stature determined using these models can then be compared. This approach has been applied to 6 Ma hominid femoral remains from the Tugen Hills, Kenya, attributed to Orrorin tugenensis. It is suggested that the best-preserved young adult individual probably weighed approximately 35–50 kg. Another fragmentary femur results in larger estimates of body mass, indicative of individual variation. The length of the femur of the young adult individual was estimated, by using anthropoid-based regression, to be a minimum of 298 mm. Because whole-femur proportions for Orrorin are unknown, this prediction is conservative and should be revised when additional specimens become available. When this predicted value was used for regression analysis of bonobos and humans it was estimated to be 1.1–1.2 m tall. This value should, however, be viewed as a lower limit.     

The current state of korean paleoanthropology

The hominid fossil and Paleolithic archaeology records from the Korean Peninsula are extensive, but relatively little is known about the Korean human evolutionary record outside this region. The Korean paleoanthropological record is reviewed here in light of major research issues, including the hominid fossil record, relative and chronometric dating, lithic analysis, hominid subsistence, and the presence of bone tools, art and symbolism. Some of the major conclusions drawn from this review include: (1) hominid fossils have been found in nine separate sites on the Korean Peninsula; (2) possible Homo erectus fossils are present in North Korea; (3) Ryonggok Cave, in North Korea, has exposed the remains of at least five archaic Homo sapiens individuals; (4) a possible burial of an anatomically modern Homo sapiens child, discovered in Hungsu Cave in South Korea, has been tentatively dated to roughly 40,000 years ago; (5) handaxes and cleavers have been found at a number of sites near Chongokni and they appear to date to at least 100,000 years ago; and (6) taphonomic studies are necessary for addressing issues related to determining the nature of hominid-carnivore interaction over similar resources (e.g. carcasses and shelter); and the presence/absence of Early Paleolithic bone tools, art, and symbolism in Korea.     

Patterns of evolution in Middle Pleistocene hominids

This paper reviews the chronology and morphological variability of Middle Pleistocene H. erectus. specimens. Functional complexes are delineated within the skull and dentition, and their total morphological patterns quantified using univariate and multivariate statistical analysis. Statistical distances are calculated between H. erectus and other hominid samples for each complex, compared to illustrate patterns of mosaic evolution within the skull and dentition of middle Quaternary hominids, and estimated evolution rates are derived. An attempt is made to relate the observed morphological patterns to ecological shifts by early hominid communities, and to assess their significance for hominid taxonomy.     

Hominid mandibular remains from Sangiran: 1952-1986 collection

Eight hominid mandibular and associated dental remains discovered between 1952-1986 from the Early Pleistocene deposits of Sangiran, Central Java, are described. Although the specimens are surface finds, their original stratigraphic positions can be reasonably inferred on the basis of coincidental sources of information. These specimens significantly increase the dento-gnathic sample available for intensive morphological investigation of the earliest Javanese hominids [Kaifu et al., 2005].     

Paleomagnetic dates of hominid remains from Yuanmou,China, and other Asian sites

Two hominid upper central incisors found in the Yuanmou Basin in southwest China in 1965 have affinities with Homo erectus fossils from Zhoukoudian, but exhibit primitive features. The Yuanmou hominid remains are alleged to be coeval with or older than African specimens dated at about 1.8 m.y.a. Recent age refinements of geomagnetic short reversal events and excursions permit assigning the Yuanmou hominid-bearing bed to the early Brunhes chron (about 0.7 m.y.a.). Magnetochronological assessments confirm that the Lantian calotte which has been dated to about 1.2 m.y.a., is the oldest reliable evidence for the emergence of Homo in eastern Asia as well as China, and that hominid fossils from Sangiran and Mojokerto, Java, do not exceed 1.1 Ma in age. These results refute the view that the genus Homo migrated into eastern Asia in the late Pliocene or the earliest Pleistocene.     

New estimates of early hominid body size

Body weights for 12 early hominid specimens are estimated based on an analysis of four variables shown to have high correlation with body size in living Old World primates. Average size estimates of around 36 kg are suggested for gracile early hominids and around 59 kg for robust early hominids. Size variation is considerably more pronounced in the robust group than in the gracile group, suggesting substantially greater sexual dimorphism in the former.     

大荔人所在层位贝壳的电子自旋共振年龄

大荔人属早期智人中较古老的类型 ,在人类起源研究中具有重要意义。采用电子自旋共振 (ESR)测年技术直接测定了采自大荔人所在层位的 3个贝壳样品的年龄 ,同时 ,进行了铀系测年分析 ,根据贝壳ESR的年龄结果 ,大荔人可能老于距今 250ka。     

Habiline variation: A new approach using STET

The problem of whether the hominid fossil sample of habiline specimens is comprised of more than one species has received much attention in paleoanthropology. The core of this debate has critical implications about when and how variation can be explained by taxonomy. In this paper, we examine the problem of whether the observed variation in habiline samples reflects species differences. We test the null hypothesis of no difference by examining the degree of variability in habiline sample in comparison with other single-species early hominid fossil samples from Sterkfontein and Swartkrans (Sterkfontein is earlier than the habiline sample, Swartkrans may be within the habiline time span). We developed a new method for this examination, which we call STandard Error Test of the null hypothesis of no difference (STET). Our sampling statistic is based on the standard error of the slope of regressions between pairs of specimens, relating all of the homologous measurements that each pair shares. We show that the null hypothesis for the habiline sample cannot be rejected. The similarities of specimen pairs within the habiline sample are not more than those observed between the specimens in the australopithecine samples we analyzed.     

Role of carnivores in the accumulation of the Sterkfontein Member 4 hominid assemblage: a taphonomic reassessment of the complete hominid fossil sample (1936-1999)

New taphonomic data on the Sterkfontein Member 4 (South Africa) fossil hominid assemblage are presented. The previous estimate of hominid individuals represented in the deposit (45) is increased to 87. New minimum numbers of hominid skeletal elements are provided, and incidences of bone surface damage inflicted by prehistoric biological agents are summarized. The hominid sample from Member 4 is composed predominately of gnathic remains and has a paucity of postcrania. This dearth of postcrania limits, to some extent, inferences about the formation of the Sterkfontein assemblage. However, carnivore tooth marks on some fossil specimens and an overall broad similarity in patterns of skeletal part representation between Sterkfontein and primate bone assemblages created by extant carnivores suggest that carnivores did have some involvement in the accumulation of the fossil hominid assemblage. Thus, this study provides support for the “carnivore‐collecting hypothesis” of Brain (Brain [ 1981 ] The Hunters or the Hunted? Chicago: University of Chicago Press), which implicates large carnivores as prominent collecting agents of hominid body parts in Sterkfontein Member 4. Evidence of bone surface damage is, however, too scant to make confident inferences about specific carnivore taxon/taxa involved in hominid bone collection at the site. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.     

The Petralona dentition—Hominid or cave bear?

Four teeth were recovered from the Petralona cave site in Greece. These specimens were considered to be hominid remains and have become part of the dental data base for the Pleistocene hominids of Europe. SEM analysis of the anamel structure of these remains reveals an enamel prism pattern which is not hominid. A walled hexagonal prism was obtained which is representative of the carnivores.Subsequent analysis of a fragment of enamel from the Petralona hominid cranium revealed a keyhole enamel prism, typical of modern man, while analysis of a number of cave bear teeth revealed an identical walled hexagonal prism, as was found in the four isolated teeth.The conclusion is that the four isolated teeth are those of the Pleistocene cave bear which frequently populated the cave.     

New discoveries and interpretations of hominid fossils and artifacts from Vindija Cave, Croatia

Beginning with excavations during the 1970s, Vindija Cave (Croatia) has yielded significant Middle and Upper Paleolithic fossil and archaeological finds. We report on seven recently identified hominid fossils, a newly associated partial hominid cranial vault from level G(3), nine possible bone retouchers, and a revised interpretation of the Mousterian artifact assemblage from the site. This new information reinforces our knowledge of the complex biocultural phenomena revealed in unit G and earlier deposits at Vindija. Six of the new hominid fossils derive from stratigraphic units G and I, while one lacks exact provenience. All specimens preserving diagnostic anatomy are from Neandertals. One of the postcranial remains, a radius fragment which exhibits Neandertal-like anatomy, comes from level G(1)and is congruent with the previously established association of Neandertals with an early Upper Paleolithic industry at the site. The partial cranial vault represents the most complete Neandertal from Vindija. The possible retouchers derive from unit G. Our analysis of these artifacts suggests that both percussion and pressure techniques may have been used by Neandertals in the final stage of tool production (retouching). This paper also presents a revision of the artifact analysis for late Mousterian level G(3). We separated raw materials into two main groups due to the differing ways that the materials fracture and the differing morphology of the debitage. The use of raw material in level G(3)is different from earlier Middle Paleolithic levels at Vindija. This indicates that the G(3)late Neandertals were making choices regarding source material somewhat more like the Upper Paleolithic people at the site. When interpreted within a larger regional framework, the Vindija archaeological and hominid fossil remains demonstrate a complex, mosaic pattern of biocultural change in the Late Pleistocene of south-central Europe.     

Cladometric analysis of Pliocene hominids

Quantification of individual crown features allows maximization of information retrieval from isolated hominid molars. The Lukeino specimen demonstrates phenetic affinity to Pan; the Lothagam fossil appears closer to a hypothetical ancestral hominid morphotype than the Laetolil specimens. Consideration of 41 metric features in a cladistic framework establishes Australopithecus afarensis as the sister taxon of Homo and of later australopithecines.     

An archaic character in the Broken Hill innominate E. 719

The additional hominid material from Broken Hill, Kabwe, Zambia, is only dubiously associated with the hominid cranium from the site and is often considered to be anatomically modern in morphology. This study identifies an archaic feature, previously recognised in Pliocene and earlier Pleistocene innominates, in the Broken Hill innominate E. 719. An acetabulo-cristal buttress of cortical bone 10 mm thick is present, and this can be clearly distinguished from the morphology present in a comparative sample of large recent Homo sapiens innominates. This observation increases the likelihood that some of the additional specimens from Broken Hill are indeed of comparable antiquity to the hominid cranium and extends the range of hominids in which the feature has been recognised.     

Variation in the Habiline Crania – Must it be Taxonomic?

The problem of whether the hominid fossil sample of habiline specimens is comprised of more than one species has received much attention in paleoanthropology. The core of this debate has significant implications about when and how variation must be explained by taxonomy. In this paper, we examine the problem of whether the observed variation in habiline sample must be interpreted to reflect species differences. We test the null hypothesis of no difference by examining the degree of variability in habiline sample in comparison with other single-species early hominid fossil samples from Sterkfontein and Swartkrans (Sterkfontein is earlier than the habiline sample; Swartkrans may be within the habiline time span). We use the standard error test for this analysis, a sampling statistic based on the standard error of the slope of regressions between pairs of specimens that relates all of the homologous measurements each pair shares. We show that the null hypothesis for the habiline sample cannot be rejected. The similarities of specimen pairs within the habiline sample are not more than those observed between the specimens in the two australopithecine samples we analyzed.