Calcar femorale variation in extant and fossil hominids: Implications for identifying bipedal locomotion in fossil hominins

The calcar femorale is an internal bony structure of the proximal femur considered to be functionally related to bipedal locomotion. Among extant primates, the presence of a calcar femorale has been so far documented in extant humans and Pan and, among extinct hominins, in the Late Miocene Orrorin, in a Pliocene Australopithecus, and in a Middle Pleistocene Homo specimen. Using high-resolution microcomputed tomography, we investigated the occurrence and morphology (i.e., shape, location, and size) of the calcar femorale in an adult sample of extant humans, Pan troglodytes, Gorilla gorilla, Pongo sp., and Papio ursinus. We also investigated for the first time the occurrence and morphology of a calcar femorale in the adult proximal femoral remains of a Late Miocene great ape (Rudapithecus) and five Plio-Pleistocene hominins from Southern and Eastern Africa (Australopithecus and Paranthropus). We took four measurements: periosteal-to-tip maximum length, maximum length excluding cortical thickness, maximum vertical height, and the distance between the most anterior and posterior limits of the root. To allow for intergeneric comparisons, estimated body size was used to standardize all measurements. Nine of 10 extant humans have a well-developed calcar femorale. Among the African apes, 6 of 10 Pan and 6 of 10 Gorilla also show a distinct calcar femorale. In Pongo (n = 9), it is only present in one captive individual. None of the five investigated Papio specimens show any trace of this structure. Only calcar femorale height, which is systematically taller and extends into the lower part of the lesser trochanter, discriminates humans from extant great apes, except for one Gorilla. The calcar femorale was absent in one Paranthropus robustus and variably developed in all other investigated fossils. These results indicate that this structure cannot be considered as a diagnostic feature of habitual bipedal locomotion and emphasize the need for further investigations of its functional role

Orang-like manual adaptations in the fossil hominoid Hispanopithecus laietanus: first steps towards great ape suspensory behaviours

Morphological and biometrical analyses of the partial hand IPS18800 of the fossil great ape Hispanopithecus laietanus (=Dryopithecus laietanus), from the Late Miocene (about 9.5 Ma) of Can Llobateres (Catalonia, Spain), reveal many similarities with extant orang-utans (Pongo). These similarities are interpreted as adaptations to below-branch suspensory behaviours, including arm-swinging and clambering/postural feeding on slender arboreal supports, due to an orang-like double-locking mechanism. This is confirmed by the long and highly curved phalanges of Hispanopithecus. The short and stout metacarpals with dorsally constricted heads, together with the dorsally extended articular facets on proximal phalanges, indicate the persistence of significant degrees of palmigrady. A powerful grasping capability is indicated by the great development of basal phalangeal tubercles, the marked insertions for the flexors on phalangeal shafts and the large pits for the collateral ligaments. The morphology of the Hispanopithecus long bones of the hand indicates a unique positional repertoire, combining orthogrady with suspensory behaviours and palmigrade quadrupedalism. The retention of powerful grasping and palmigrady suggests that the last common ancestor of hominids might have been more primitive than what can be inferred on the basis of extant taxa, suggesting that pronograde behaviours are compatible with an orthograde bodyplan suitable for climbing and suspension

Author Correction: A new ape from Türkiye and the radiation of late Miocene hominines (Communications Biology, (2023), 6, 1, (842), 10.1038/s42003-023-05210-5)

Correction to: Communications Biology, published online 23 August 2023. In the original version of the Article, two authors and their affiliations were omitted. In the original version of the Article, author first names were not provided for all authors. The corrected author list and affiliations are provided below. This has now been corrected in the HTML and PDF versions of the article. Ayla Sevim-Erol1, David R. Begun2, Alper Yavuz3, Erhan Tarhan4, Çilem Sönmez Sözer1, Serdar Mayda5, Lars W. van den Hoek Ostende6, Robert M. G. Martin2 ;amp; M. Cihat Alçiçek7 1 Ankara University, Faculty of Languages History and Geography, Department of Anthropology, Ankara, Türkiye 2 Department of Anthropology, University of Toronto, Toronto, ON, Canada 3 Mehmet Akif Ersoy University of Science and Letters, Department of Anthropology, Burdur, Türkiye 4 Hitit University Faculty of Science and Letters, Department of Anthropology, Çorum, Türkiye 5 Ege University Fakulty of Science, Department of Biology, İzmir, Türkiye 6 Naturalis Biodiversity Center, Leiden, The Netherlands 7 Pamukkale University, Department of Geology, 20070 Denizli, Türkiye The Author Contributions section should read “A.S.E. is the PR of the project, secured funding for excavations and lab analysis and directed excavations. A.S.E. and D.R.B. are responsible for data curation, acquired funding and supervised research. D.R.B. conceptualized the analysis, conducted the investigation, developed the methodology, prepared the original draft and all subsequent versions. C.S.S., S.M., L.W.vdH. and C.A. contributed their analysis of geological and paleontological results. R.M.G.M. was responsible for the segmentation and analysis of the scans of the mandible. A.Y and E.T. participated in the excavations.” This has now been corrected in the HTML and PDF versions of the article. © 2023, Springer Nature Limited

Skull reconstruction of the late Miocene ape Rudapithecus hungaricus from Rudab\ue1nya, Hungary

We report on a computer-based reconstruction of a well-preserved ape skull from late Miocene deposits in Rudab\ue1nya, Hungary. Based on micro-computed tomographic scans of the original Rudapithecus hungaricus partial cranium RUD 200 and the associated mandible RUD 212 we realign displaced bone fragments, and reconstruct the shape of the upper and lower jaws guided by occlusal fingerprint analysis of dental wear patterns. We apply geometric morphometric methods based on several hundred landmarks and sliding semilandmarks to estimate missing data, and create multiple reconstructions of the specimen. We then compare the reconstructed overall cranial shape, as well as the volume and shape of the endocast, with extant primates. Multiple reconstructions of RUD 200 yield an average endocranial volume of 234 cc (S.D.: 9 cc; range: 221\u2013247 cc). RUD 200 is most similar to African apes in overall cranial shape, but in a statistical analysis of endocranial shape the specimen falls closest to extant hylobatids. Our data suggest that R. hungaricus from the late Miocene in Europe displays aspects of the overall cranial geometry typical of extant African great apes, but it does not show an evolutionary reorganization of the brain evident in Pan, Gorilla, and Pongo