Search

A hominin mandible, KNM-ER 63000, and associated vertebrate remains were recovered in 2011 from Area 40 in East Turkana, Kenya. Tephrostratigraphic and magnetostratigraphic analyses indicate that these fossils date to ∼4.3 Ma. KNM-ER 63000 consists of articulating but worn and weathered mandibular corpora, with a broken right M 2 crown and alveoli preserved at other tooth positions. Despite extensive damage, KNM-ER 63000 preserves diagnostic anatomy permitting attribution to Australopithecus anamensis. It can be distinguished from Australopithecus afarensis by its strongly inclined symphyseal axis with a basally convex, 'cut-away' external surface, a lateral corpus that sweeps inferomedially beneath the canine-premolar row, and alignment of the canine alveolus with the postcanine axis. KNM-ER 63000 is distinguished from Ardipithecus ramidus by its thick mandibular corpus and large M 2 crown. The functional trait structure and enamel's stable carbon isotopic composition of the Area 40 large-mammal community suggests an environment comparable to Kanapoi and other ∼4.5–4 Ma eastern African sites that would have offered Au. anamensis access to both C 3 and C 4 food resources. With an age of ∼4.3 Ma, KNM-ER 63000 is the oldest known specimen of Au. anamensis , predating the Kanapoi and Asa Issie samples by at least ∼100 kyr. This specimen extends the known temporal range of Au. anamensis and places it in temporal overlap with fossils of Ar. ramidus from Gona, Ethiopia. The morphology of KNM-ER 63000 indicates that the reconfigured masticatory system differentiating basal hominins from the earliest australopiths existed in the narrow temporal window, if any, separating the two. The very close temporal juxtaposition of these significant morphological and adaptive differences implies that Ar. ramidus was a relative rather than a direct phyletic ancestor of earliest Australopithecus. [ABSTRACT FROM AUTHOR]

The Tacna region in southern Peru hosts archaeological remnants of Pre-Columbian period human occupations, including the Miculla Petroglyphs. Existing methods for dating these petroglyphs present substantial uncertainties and are subject to claims lacking objective validation. This study employs advanced hyperspectral analysis, specifically utilizing the SPECIM IQ camera, to reevaluate existing chronological proposals for these petroglyphs. The employed analytical technique is non-destructive and captures spectral data across an extensive range of wavelengths. This allows for a quantitative assessment of patination levels attributable to solar exposure, in comparison to adjacent intact areas. Data from various petroglyphs were analyzed using SPECIM IQ Studio software and Matlab. The analysis differentiated between "engraved" and "varnished" regions on selected boulders. Reflectance ratios between these areas were compared to provide insights into the potential relative ages of different sets of engravings. The results question pre-existing chronologies based on cultural classification schemes for the petroglyphs. While the study underscores the utility of hyperspectral analysis in refining petroglyph dating, it also indicates that this method cannot replace a multi-method approach without further resolution refinement. • Hyperspectral analysis suggests time-dependent varnish patterns for Miculla Petroglyphs. • Patination levels assessed via SPECIM IQ camera across extensive wavelengths. • Reflectance ratios hint at varying ages for different petroglyph sets. • Study presents a methodology requiring statistical analysis for robust dating. • Future work advocates multi-method approach combining HSI with other dating methods. [ABSTRACT FROM AUTHOR]

The claims that children's hand and footprints on formerly soft travertine at Qiusang, Tibet, are about 200 ka old and are the earliest rock art on the planet are reviewed. The uranium-thorium results are inconsistent with a previous age estimate of another set of such prints nearby, which is itself at odds with finger-drawn Tibetan letters at that site. The claims also ignore the high susceptibility of open-site calcite travertine to surface retreat by weathering and the likely removal of uranium by rainwater. Similarly, deposition of detrital thorium can occur in such porous and weathered carbonates. Both processes are known to increase age estimates of reprecipitated carbonate deposits significantly. There is no evidence that hominins of the Middle Pleistocene occupied the central Tibetan Plateau during the penultimate glacial period. Several issues are considered, and recommendations are made for resolving the controversy. • The difficulties with applying uranium-thorium analysis to the dating of travertine are illuminated. • The most recent sensational claims based on this dating approach concern an open travertine site in Tibet. • It has been proposed that some hand and footprints are in the order of 200,000 years old. • The discovery of Tibetan writing characters suggests that the travertine markings can only be less than 1300 years old. • The significant discrepancy in this and previous studies is explained by leaching of uranium. [ABSTRACT FROM AUTHOR]