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Tag: Biological & Physical Anthropology

  • Drimolen postcranial fossils support mixed hominin attribution

    What the study found

    The study found that the Drimolen Main Quarry postcranial fossils are mostly attributable to Paranthropus robustus, although a few specimens may be linked to Homo aff. erectus. The authors also report that the hominins were small-bodied and committed to terrestrial bipedality, or walking on two legs on land.

    Why the authors say this matters

    The authors conclude that these remains add information about the paleobiology of the Drimolen hominins. They also suggest that the findings may reflect taxonomic variation or evolutionary mosaicism, meaning different body parts may have evolved at different rates or in different combinations.

    What the researchers tested

    The researchers cataloged isolated postcranial specimens recovered between 1994 and 2015 from Drimolen Main Quarry in Gauteng Province, South Africa. They provided formal descriptions and carried out comparative and functional analyses of the fossil bones.

    What worked and what didn't

    Twenty-eight fossil specimens were cataloged, and two earlier specimens previously considered possibly hominin were removed from that category. DNH 32 and DNH 43 could be assigned to Paranthropus robustus with some confidence, while DNH 150a and b may be associated with the juvenile Homo aff. erectus cranium DNH 134. Most other specimens probably belong to Paranthropus robustus, but the mixed assemblage made taxonomic attribution difficult.

    What to keep in mind

    The abstract does not describe all specimens as securely identified, and it notes that attribution is challenging because Drimolen contains a mixed hominin assemblage. It also indicates that the interpretation of the first metatarsal is uncertain, since its curved joint may suggest increased hallucal divergence in that individual.

    • Twenty-eight Drimolen postcranial fossils were cataloged, and two possible hominin specimens were reclassified out of that status.
    • Most of the postcranial remains were probably from Paranthropus robustus.
    • Some material, including infant neural arches, may be associated with Homo aff. erectus.
    • Functional analyses indicated small-bodied hominins adapted to terrestrial bipedality.
    • A first metatarsal showed a curved joint that may suggest increased hallucal divergence in one individual.

  • Third molar PDL visibility helped distinguish age 21 status

    What the study found

    Periodontal ligament (PDL) visibility staging in third molars was associated with age and showed good ability to separate individuals who were at least 21 years old from those who were younger. The authors describe this as a reliable, reproducible complementary tool for forensic age estimation around that threshold.

    Why the authors say this matters

    The study suggests this may be useful for forensic age estimation in living individuals near legally relevant age thresholds, where exact age prediction is difficult after dental maturation is complete. The authors conclude it may support probabilistic decision-making in legally relevant age assessment and contribute to a multimodal forensic age estimation framework.

    What the researchers tested

    The researchers retrospectively analyzed 1,049 digital orthopantomograms, which are panoramic dental X-rays, from Turkish individuals aged 15 to 25 years. They assessed PDL visibility in maxillary and mandibular third molars using the Olze et al. staging system and examined links with age, sex, and tooth position. They also used receiver operating characteristic analysis to test performance for identifying people aged 21 years or older.

    What worked and what didn't

    More advanced PDL visibility stages were significantly associated with increasing age. Mandibular third molars provided the most informative staging patterns, and the model showed an area under the curve of 0.79 for the 21-year threshold, which the authors describe as good discriminative accuracy with balanced sensitivity and specificity. Substantial intra- and inter-observer agreement was reported, supporting methodological reliability.

    What to keep in mind

    The study was limited to a Turkish population and to people aged 15 to 25 years, so the findings are framed within that scope. The abstract does not provide detailed limitations beyond this, and the authors emphasize that the method supports threshold-based classification rather than exact age prediction.

    • PDL visibility in third molars increased with age.
    • Mandibular third molars were the most informative teeth in the analysis.
    • The method showed an AUC of 0.79 for distinguishing individuals aged 21 years or older.
    • Observer agreement was substantial for both repeated and between-observer assessments.
    • The authors describe the method as a complementary tool, not an exact age predictor.