Human childbirth is regarded as uniquely difficult among primates, due to a tight cephalopelvic fit thought to result from an evolutionary trade-off between adaptations to bipedal locomotion and increasing brain size. This impression, however, may be an artefact of past adoption of anthropocentric measurements that underestimate birth challenges in non-human primates. Here we re-evaluate cephalopelvic proportions using species-specific three-dimensional data of the pelvic inlet along with neonatal cranial dimensions from a broad sample of extant primates. Results reveal that maternal body size is a key factor to consider. A tight cephalopelvic fit occurs in species with proportionately larger neonates, smaller pelves or a combination of both. The latter is the case in humans, producing the tightest fit among extant apes, but a similar combination of factors explains much more extreme cephalopelvic proportions in other species. Our findings reveal a diversity of obstetrical dilemmas across primates.

OBJECTIVES:The unfused human pubic symphysis has been interpreted as an obstetric adaptation to facilitate the passage of a large-brained baby through a relatively small, bipedally adapted pelvis. The degree of fusion of the adult pubic symphysis was evaluated across primate species to gauge whether an open symphysis can be interpreted as an obstetric adaptation in humans and other primates. MATERIALS AND METHODS:Symphyseal fusion was assessed in 718 individuals from 67 nonhuman primate species. Variation in fusion in specimens of known ages and sex from four species (Galago moholi, Macaca mulatta, Microcebus murinus, and Pan troglodytes) was further examined, with detailed analyses of pubic changes by age and sex carried out through logistic regressions in macaques. RESULTS:Pubic fusion occurs in most primate species. It is observed earlier in life in males than in females in Ma. mulatta and Pa. troglodytes, only in males in Mi. murinus, and does not occur in Ga. moholi. DISCUSSION:While delayed or absent pubic fusion is more prevalent in female primates, suggesting obstetric adaptation, there is no clear relation with childbirth constraints, as fusion is also observed in species experiencing a tight cephalopelvic fit. Other mechanisms might have evolved to facilitate birth in some species, or nonobstetric selective pressures might be counteracting the obstetric advantages of a flexible symphysis. The preservation of an open symphysis throughout life in humans and some other primates, however, can be best interpreted as convergent evolution due to obstetric selection.

Human childbirth is regarded as uniquely difficult among primates, due to a tight cephalopelvic fit thought to result from an evolutionary trade-off between adaptations to bipedal locomotion and increasing brain size. This interpretation, however, may be an artefact of anthropocentric measurements that underestimate birth challenges in non-human primates. Here, we re-evaluate cephalopelvic proportions using species-specific three-dimensional data of the pelvic inlet, along with neonatal cranial dimensions in both sinciput and face presentation from a broad sample of extant primates, demonstrate that a tight fit is not exclusive to humans, and that higher cephalopelvic proportions occur in various other primates. The results reveal that maternal body size is a key variable in understanding primate variation in fetopelvic fit: smaller species have relative larger neonates as well as a relatively smaller pelvic canal, leading to high cephalopelvic proportions. Extremely tight cephalopelvic fit occurs in species with proportionately larger neonates, smaller pelves or a combination of both. The latter is the case in humans, producing the tightest fit among extant apes, but a similar combination of factors explains much more extreme cephalopelvic proportions in other species, revealing a diversity of obstetrical dilemmas across primates.

Accessible and engaging, this is the definitive textbook on using teeth to study the demography and ways of life in ancient human communities. Based on extensive laboratory and field experience, this new edition combines archaeological approaches with new technologies and methodologies, covering the key advances in anatomy, forensics, 3D imaging, stable isotopes, and proteomics. Hillson provides a biological context for teeth, a guide on key skills, an introduction to current debates, and advice for the excavation, conservation and recording of dental remains. He also showcases the microscopic structure of dental tissues alongside methods of age-determination. Discover solutions to problems such as identifying worn, fragmentary human teeth or understanding their condition. This is the ideal reference for advanced courses in anthropology or archaeology, and for everyone interested in dental remains from archaeological sites, museum collections or forensic cases. Online teaching resources include videos of lectures and practicals.

The evolution of human pelvic form is primarily studied using disarticulated osteological material of living and fossil primates that need rearticulation to approximate anatomical position. To test whether this technique introduces errors that impact biological signals, virtual rearticulations of the pelvis in anatomical position from computed tomography scans were compared with rearticulated models from the same individuals for one female and one male of Homo sapiens, Pan troglodytes, Macaca mulatta, Lepilemur mustelinus, Galago senegalensis, and Nycticebus pygmaeus. "Cadaveric" pelvic bones were first analyzed in anatomical position, then the three bones were segmented individually, intentionally scattered, and "rearticulated" to test for rearticulation error. Three-dimensional landmarks and linear measurements were used to characterize the overall pelvis shape. Cadaveric and rearticulated pelves were not identical, but inter-specific and intra-specific shape differences were higher than the landmarking error in the cadaveric individuals and the landmarking/rearticulation error in the rearticulated pelves, demonstrating that the biological signal is stronger than the noise introduced by landmarking and rearticulation. The rearticulation process, however, underestimates the medio-lateral pelvic measurements in species with a substantial pubic gap (e.g., G. senegalensis, N. pygmaeus) possibly because the greater contribution of soft tissue to the pelvic girdle introduces higher uncertainty during rearticulation. Nevertheless, this discrepancy affects only the caudal-most part of the pelvis. This study demonstrates that the rearticulation of pelvic bones does not substantially affect the biological signal in comparative 3D morphological studies but suggests that anatomically connected pelves of species with wide pubic gaps should be preferentially included in these studies.

Objectives Due to taphonomic processes, fossils have often undergone plastic deformation. To correctly assess the morphological affinities of such specimens, the original antemortem shape of the deformed specimens must be reconstructed. Here we describe a method to mathematically isolate and selectively eliminate the taphonomic deformation of a fossil cranium for restoration of its original antemortem appearance, and apply this method to reconstruction of a cranium of Mesopithecus from the late Miocene of Greece. Materials and methods Three-dimensional (3D) models of the fossil cranium and the crania of phylogenetically close extant species were generated, and 3D shape variations of the crania were analyzed based on anatomical and sliding semi-landmarks. Using principal component analysis, we attempt to extract the taphonomic deformation component of the shape variation that is presumably orthogonal to the hyperplane describing interspecific variations of the intact crania of the extant species. Landmarks were repositioned so that the extracted taphonomic component is selectively eliminated. A thin-plate spline was used to describe the 3D transformation from original and repositioned landmarks, and the entire surface of the fossil was restored. Results The proposed method successfully extracted and eliminated the component of the taphonomic deformation and enabled restoration of the original antemortem appearance of the deformed fossil cranium. Discussion Unlike conventional methodologies, the proposed method does not rely on the assumption of symmetry for correction of taphonomic deformation. Although some methodological limitations apply, the proposed method may contribute to improved accuracy, objectivity, and transparency in virtual reconstruction of deformed cranial fossils.

The frontal sinuses are cavities inside the frontal bone located at the junction between the face and the cranial vault and close to the brain. Despite a long history of study, understanding of their origin and variation through evolution is limited. This work compares most hominin species' holotypes and other key individuals with extant hominids. It provides a unique and valuable perspective of the variation in sinuses position, shape, and dimen-sions based on a simple and reproducible methodology. We also observed a covariation between the size and shape of the sinuses and the underlying frontal lobes in hominin species from at least the appearance of Homo erectus. Our results additionally undermine hypotheses stating that hominin frontal sinuses were directly affected by biomechanical constraints resulting from either chewing or adaptation to climate. Last, we demon-strate their substantial potential for discussions of the evolutionary relationships between hominin species.

The cranium (Broken Hill 1 or BH1) from the site previously known as Broken Hill, Northern Rhodesia (now Kabwe, Zambia) is one of the best preserved hominin fossils from the mid-Pleistocene. Its distinctive combination of anatomical features, however, makes its taxonomic attribution ambiguous. High resolution microCT, which has not previously been employed for gross morphological studies of this important specimen, allows a precise description of the internal anatomical features of BH1, including the distribution of cranial vault thickness and its 2 internal composition, paranasal pneumatisation, pneumatisation of the temporal bone and endocranial anatomy. Relative to other chronologically and taxonomically relevant specimens, BH1 shows unusually marked paranasal pneumatisation and a fairly thick cranial vault. For many of the features analysed, this fossil does not exhibit the apomorphic conditions observed in either Neandertals or Homo sapiens. Its morphology and the general shape of the brain and of the skull may be partly explained by an allometric relationship relative to the features observed in Homo erectus s.l. However, further research is still necessary to better appreciate the cranial anatomy of BH1 and the role of Homo rhodesiensis/Homo heidelbergensis in the course of human evolution. This paper also deals with more general aspects of scientific practices in palaeoanthropology. In particular, we give precise descriptions of many internal anatomical features of Broken Hill 1, a specimen discovered in 1921. This important and unique dataset will allow independent comparative studies in the future. However, we were …

This cross-sectional study estimates the costs incurred by the National Health Service (NHS) in England as a consequence of the unnecessary prescribing (i.e. non-indicated or dispensable) of dependency-forming medicines (antidepressants, opioids, gabapentinoids, benzodiazepines, Z-drugs). It assesses prescribing in primary care from April 2015-March 2018. Analyses were based upon the following data sets: the number of adults continuously prescribed dependency forming medications and the duration of prescriptions (obtained from Public Health England); the Net Ingredient Cost (NIC) and the dispensing costs for each medicine (obtained from the NHS Business Service Authority [NHSBSA]). Consultation costs were calculated based on guideline recommendations and the number of consultations evidenced in prior research for long-term medication monitoring. Across opioids, gabapentinoids, benzodiazepines, Z-drugs the total estimated unnecessary cost over three years (April 2015-March 2018) was £1,367,661,104 to £1,555,234,627. For antidepressants the total estimated unnecessary cost for one year was £37,321,783 to £45,765,504. The data indicate that the NHS in England may incur a significant estimated mean annual loss of £455,887,035 to £518,411,542 for opioids, gabapentinoids, benzodiazepines, Z-drugs and an estimated annual loss of £37,321,783 to £45,765,504 for antidepressants. Combined, this gives an estimated annual loss of £493,208,818 to £564,177,046 as a result of non-indicated or dispensable prescribing of dependency-forming medicines. Estimates are conservative and figures could be higher.

There is considerable variation in mid-late Pleistocene hominin paranasal sinuses, and in some taxa distinctive craniofacial shape has been linked to sinus size. Extreme frontal sinus size has been reported in mid-Pleistocene specimens often classified as Homo heidelbergensis, and Neanderthal sinuses are said to be distinctively large, explaining diagnostic Neanderthal facial shape. Here, the sinuses of fossil hominins attributed to several mid-late Pleistocene taxa were compared to those of recent H. sapiens. The sinuses were investigated to clarify differences in the extent of pneumatisation within this group and the relationship between sinus size and craniofacial variation in hominins from this time period. Frontal and maxillary sinus volumes were measured from CT data, and geometric morphometric methods were used to identify and analyse shape variables associated with sinus volume. Some mid-Pleistocene specimens were found to have extremely large frontal sinuses, supporting previous suggestions that this may be a diagnostic characteristic of this group. Contrary to traditional assertions, however, rather than mid-Pleistocene Homo or Neanderthals having large maxillary sinuses, this study shows that H. sapiens has distinctively small maxillary sinuses. While the causes of large sinuses in mid-Pleistocene Homo remain uncertain, small maxillary sinuses in H. sapiens most likely result from the derived craniofacial morphology that is diagnostic of our species. These conclusions build on previous studies to overturn long-standing but unfounded theories about the pneumatic influences on Neanderthal craniofacial form, whilst opening up questions about the ecological correlates of pneumatisation in hominins.

New material of the Mio-Pliocene colobine Mesopithecus from the Turolian locality of Kryopigi (Greece) is described here. It includes a complete skull with the atlas attached and other dental and postcranial elements representing at least five individuals (four males and one female). The material is compared with Mesopithecus delsoni, Mesopithecus pentelicus, Mesopithecus monspessulanus and intermediate forms from more than a dozen Turolian localities of the Greco-Iranian province. These comparisons support the attribution of the Kryopigi material to M. pentelicus. The chronostratigraphic distribution of Mesopithecus species and intermediate forms suggests that the Kryopigi fauna could be dated as younger than the Perivolaki locality with M. delsoni/pentelicus (7.1-7.3 Ma, MN12) and older than the Dytiko localities with M. aff. pentelicus, M. cf. pentelicus and M. cf. monspessulanus ( ?middle MNI3). The dimensions of the atlas are within the distribution of extant colobines. The skull shows bite-marks, probably caused by the hyaena Adcrocuta eximia. (C) 2018 Elsevier Ltd. All rights reserved.

Three adaptive hypotheses have been forwarded to explain the distinctive Neanderthal face: (i) an improved ability to accommodate high anterior bite forces, (ii) more effective conditioning of cold and/or dry air and, (iii) adaptation to facilitate greater ventilatory demands. We test these hypotheses using three-dimensional models of Neanderthals, modern humans, and a close outgroup (Homo heidelbergensis), applying finite-element analysis (FEA) and computational fluid dynamics (CFD). This is the most comprehensive application of either approach applied to date and the first to include both. FEA reveals few differences between H. heidelbergensis, modern humans, and Neanderthals in their capacities to sustain high anterior tooth loadings. CFD shows that the nasal cavities of Neanderthals and especially modern humans condition air more efficiently than does that of H. heidelbergensis, suggesting that both evolved to better withstand cold and/or dry climates than less derived Homo We further find that Neanderthals could move considerably more air through the nasal pathway than could H. heidelbergensis or modern humans, consistent with the propositions that, relative to our outgroup Homo, Neanderthal facial morphology evolved to reflect improved capacities to better condition cold, dry air, and, to move greater air volumes in response to higher energetic requirements.