Radio – Ulnar Weight Index — is it a Useful Criterion for Sex Identification of the Human Skeleton?

Sex identification of human long bones has been studied by several investigators. Measurements of the radius and the ulna have also been reported as an indicator of sex by reference to separate parameters and/or to combinations of the parameters of a single bone. This study was designed to determine whether the radius and the ulna can provide reliable information for the sexing of human bones, as can the lower leg bones, if the forearm measurements include the weight index of the two bones as a parameter. The materials consisted of the dried radii and ulnae of 20 recently deceased Japanese males and 20 similar females. Almost all the dimensions exhibited statistically significant sex differences. The radio–ulnar weight index did not, however, differ between the sexes. In discriminant analysis, the rate of correct sex discrimination based on distances between various pairs of points was not improved by the inclusion of the radio–ulnar weight index. Therefore, the radio–ulnar weight index cannot be recommended as a parameter for the sexing of human bones.     

Genetic sexing to determine the optimal discriminant functions for the analysis of archaeological remains from El Hierro (Canary Islands)

A correct sex assignment of a given bone or bone fragment is of paramount importance for the archaeologist, anthropologist and in forensic medicine. Discriminant functions, combining several anthropometric measurements obtained from individuals with known sex are useful tools for this purpose, but it is essential to know exactly the sex from which the measures are obtained. This is an easy task in modern populations, but it is problematic in ancient ones, since even when the entire skeleton is available, diagnosis of sex is not 100% accurate. Sexing by genetic methods by amplifying the first intron of the amelogenin gene constitutes a much more accurate method for sexing bones and may be the gold standard for further elaboration of discriminant functions which may serve for sexing new bones dug up in future excavations. With this aim we have genetically sexed 52 (out of 59) tibiae belonging to the prehispanic population of El Hierro, in the Canary Islands, identifying 18 women and 34 men, and then, performed discriminant functions combining several anthropometric variables. These functions show a high accuracy in sex diagnosis (94.2%; area under ROC curve = 0.954 with the best of the functions), so that they allow correct sexing of tibiae or tibiae fragments (only proximal third, distal third or midshaft). Thus, genetic sexing obviates the problem of finding an accurate gold standard for the elaboration of discriminant functions for ancient bones. This method could be applied to other populations of different antiquity and different ethnicity.     

Diameter of the human internal acoustic meatus and sex determination

We report the results of testing the diameter of the internal opening of the acoustic canal in the petrous part of the temporal bone for sex determination of skeletal remains. The method involves measuring the diameter using a suite of ordinary drills. The method is very simple and has the great advantage of utilising one of the sturdiest bone elements of the human skeleton. The method may be especially useful for the analyses of very fragmented skeletal remains or cremated bones, where the petrous bone may still be readily recognisable. The method was tested using a forensic sample of 113 left petrous bones with known sex. Intra‐ and inter‐observer testing was also performed. We found a statistically significant difference in diameter between males and females (means: males: 3.7 mm; females: 3.4 mm; P < 0.009). However, the low predictive value (70%) for correct sexing using two sectioning points ( < 3.0 mm = female; >3.5 mm = male) was disappointing. No additional accuracy was gained by employing both left and right petrous bones (a bilateral sample of 60 petrous bones was also tested), although left and right side diameter is highly correlated (R = 0.778; P = 0.0001). Copyright © 2005 John Wiley & Sons, Ltd.     

Osteometric and molecular sexing of cattle metapodia

Sex identification of skeletal remains based on morphology is a common practice in Zooarchaeology. Knowledge of the sex distribution of slaughtered or hunted animals may help in the interpretation of e.g. hunting or breeding strategies. Here we investigate and evaluate several osteometric criteria used to assess sex of cattle (Bos taurus) metapodia using molecular sex identification as a control of the metric data. The bone assemblage used to assess these new criteria derives from the Eketorp ringfort in the southern parts of Öland Island in Sweden. One hundred metapodia were selected for molecular analysis of sex and we were able to genetically identify the sex of 76 of these elements. The combined results of the molecular and osteometric analyses confirm a significant size difference between females and males for several measurements for both metacarpals (Mc) and metatarsals (Mt). Our results show that some measurements are applicable for metapodials. These measurements include the slenderness indices such as the Mennerich’s index 1 and 3, as well as the distal breadth (Bd), the breadth between the articular crests (Bcr), and the maximum breadth of the lateral trochlea (BFdl). We show that they can be used for sexing of both metacarpals and metatarsals. The latter measurements offer an opportunity to study fragmented elements and thus a higher number of elements may be utilized for morphological sexing of archaeological bones. Size comparisons of Mc and Mt may also aid in the separation of bulls and oxen.     

Sexual dimorphism in limb bones of ibex (Capra ibex L.): mixture analysis applied to modern and fossil data

Estimating sex ratios of fossil bone assemblages is an important step in the determination of demographic profiles, which are essential for understanding the palaeobiology and palaeoethology of any particular species, as well as its exploitation patterns by humans. This is especially true for ibex (Capra ibex), which was a main source of food for hominids during Pleistocene times. Classical methods for determining sexual dimorphism and sex ratio, such as analyses using uni‐ and bivariate plots, are based on an arbitrary fixing of limits between sexes. Here we use a more robust statistical method termed mixture analysis (MA) to determine the sex of postcranial remains (long bones, metapodials and tarsals) from ibex. For the first time, we apply MA to both a modern and a fossil sample of one species, by using metric data taken from (i) a collection of present‐day ibex skeletons and (ii) a Palaeolithic sample of the same species. Our results clearly show that the forelimb (humerus and radius) is more dimorphic than the hindlimb (femur and tibia) and is therefore better suited for sexing ibex. It also appears that metapodials should be used carefully for estimating sex ratios. On the basis of these results, we propose a classification of bone measurements that are more or less reliable for sexing ibex. The results of MA applied to the ibex fossil bones from the Upper Palaeolithic site of the Observatoire (Monaco) lead us to the conclusion that this assemblage consists of a majority of males. The quantitative estimations calculated by the MA make it possible to compare the size of Pleistocene and modern ibex for the whole set of variables used in this study. Copyright © 2006 John Wiley & Sons, Ltd.     

An exploration of character traits and linear measurements for sexing mountain gazelle (Gazella gazella) skeletons

The skeletal elements of mountain gazelle (Gazella gazella) have proven difficult to sex with statistical confidence due to wide overlap in the body size of the two sexes. We studied a sample of 53 modern mountain gazelle skeletons to determine which character traits and metric measurements best predict sex. The success of the character traits was determined using blind tests while the metrics were examined using discriminant function analysis. The most useful elements include the previously identified horn core, pubis and atlas, but also some new bone portions that preserve well in the archaeological record (e.g., distal tibia, distal metacarpal and metatarsal, and second phalanx). Surprisingly, two elements commonly used in sexing analyses (distal humerus and astragalus) were not among the most effective elements. Although cutting points and discriminant functions for sexing gazelle bone portions are presented here, they do not account for potential body size change and thus are not suited for direct application to archaeological assemblages. Instead, we provide guidelines for application to archaeological gazelle assemblages, most importantly a regression analysis that considers the sex ratios obtained from multiple measurements to predict the sex ratio of archaeological gazelle populations.     

New evidence for the antiquity of leprosy in early Britain

Examination of skeletons excavated in Dorset has probably produced the earliest example of leprosy known in northern Europe. The site, Poundbury Camp, Dorchester, was excavated under the direction of C. J. S. Green for the Dorchester Excavation Committee from 1966 to 1973. It is a Romano-British cemetery, apparently Christian, and the leprous bones are dated by their archaeological context to the middle of the fourth century AD.The specimen consists of the distal portions of right and left tibiae and fibulae, and the right and left feet. The right intermediate cuneiform is missing, but this may be a post-mortem loss. All parts of the skeleton above the mid-shaft of the tibiae and fibulae have been lost due to modern disturbance. It is therefore impossible to estimate the sex of the individual or its age, but the bones are certainly those of a mature adult.The following pathological changes were noted.     

Molecular and osteometric sexing of cattle metacarpals: a case study from 15th century AD Beja,Portugal

In the course of a zooarchaeological survey of Holocene sites in southern Portugal, a substantial size increase of cattle bones was noted following the Christian reconquista of the 11th–13th centuries AD. A size increase in the course of time within a lineage of domestic livestock is usually considered to represent animal improvement. However several other factors including sex may influence the average size of a sample of mammal bones – cattle exhibit considerable sexual size dimorphism, with bulls being larger than cows. A histogram of the distal widths of a large (n = 44) sample of cattle metacarpals from 15th century Beja (Alentejo, Portugal), revealed a bimodal distribution. It was assumed that the large measurements belonged to males and the small to females. In order to rule out the possibility of a post-Moslem change in the sex ratio of cattle, a sub-sample of 21 cattle metacarpals from Beja was selected and we used genetic markers to identify the sex of the animals to which these metacarpals belonged. The ancient DNA sex of all specimens agreed with the previously assumed sex as determined osteometrically. We conclude that the two nearly separated peaks for the metacarpal distal width measurements do indeed indicate sex. A similar bimodal distribution was obtained from another large but earlier sample of cattle metacarpals from Moslem Alcáçova de Santarém (9th–12th century AD). Although these have not been molecularly sexed and since osteometric sexing has now been validated, we conclude that both small (female) and large (male) peaks are smaller than the 15th century ones and that there was an overall size increase or improvement of cattle in this region. Why the Christians improved cattle is unclear, but a selection for larger beeves for meat is one possibility as is the selection of more robust cattle for power. The spread of the quadrangular or chariot plough in Iberia is known to have occurred at this time. We then use the genetically sexed metacarpals to determine which measurements provide reasonable distinction between the sexes. Both the distal width (BFd; as already noted by Svensson et al., 2008; in Swedish medieval cattle) and the width of the lateral condyle (WCL) offer the best distinction. We also used them as a reference ‘collection’ to sex the medieval and post-medieval cattle metacarpals from Launceston Castle in England. This re-visit of the Launceston data corroborates other evidence indicating increased specialisation (milk and veal) in post-medieval cattle husbandry in England.     

Standardization of long bone growth in children

Diaphyseal lengths of long bones of juveniles from five prehistoric Native American populations were collected in order to test the hypothesis of equivalence of relative lengths of all long bones. Results indicate that the relative lengths of all long bones are not equivalent and that the long bones of the Native Americans exhibit a consistent, significant sequence from relatively most affected (relatively smallest) to relatively least affected (relatively longest): femur, fibula, tibia, humerus, ulna and radius. This sequence can be explained if it is assumed that the most rapidly growing long bones are the most greatly affected by nutritional and disease stress.     

Further developments in molecular sex assignment: a blind test of 18th and 19th century human skeletons

The identification of sex in human remains recovered from archaeological locations is important in order to understand the social and biological structure of past societies, and to reconstruct past population demographic events. Sex determination is usually based on morphological traits of the skeletons, with the drawback that most methods do not apply to juveniles and require well preserved remains. In cases where morphological methods cannot be used, or are ambiguous, methods of molecular sexing systems are an alternative. In this methodological study we tested and validated the accuracy and usefulness of a molecular sexing method based on the amelogenin gene using pyrosequencing. We did this in a double blind study of documented 18th and 19th century human remains.     

Disentangling long bones of foxes (Vulpes vulpes and Alopex lagopus) from arctic archaeological sites

To discern the presence of two anatomically close species within an archaeological assemblage is always a problem for the analyst. A particularly interesting case is the distinction between the red fox (Vulpes vulpes) and the arctic fox (Alopex lagopus), which is often determined using non-rigorous criteria and producing results that must be regarded with caution. Classical methods for separating these two species and determining sexual dimorphism, and eventually the sex ratio, such as analyses using uni- and bivariate plots, are based on arbitrarily fixed limits between sexes. In this text, a more robust statistical method termed mixture analysis (MA) is used to determine the species of limb bones from foxes. First, the MA is applied to a sample of each species using metric data taken from a collection of present-day fox skeletons. Afterwards, the MA is applied to archaeological samples dated to the Dorset period and retrieved from the Tayara site (near Salluit, South Hudson Strait, Nunavik). The results clearly demonstrate that the greatest length (GL) of long bones, especially the humerus and tibia, is the best measurement for distinguishing the species, followed by the distal breadth and the proximal breadth; and that GL is better suited for sexing foxes. The results of MA applied to the Tayara site collection lead to the conclusion that the red fox is present along with the arctic fox among the assemblage, and that there is no fox body size change during the last two millennia in the Eastern Arctic.     

Canary islands aborigin sex determination based on mandible parameters contrasted by amelogenin analysis

Sex determination using mandible parameters is population dependent. In order to assess which measurements better characterize sex in prehispanic individuals from the Canary Islands, we blindly contrasted the results obtained by visual inspection and osteometric measurements with those obtained by molecular sexing using amelogenin ancient DNA analysis on teeth from the same material. Unambiguous sex classification was achieved by amplification of sex specific amelogenin alleles in 56 out of 76 mandibles (73.78% of the cases). Visual inspection led to a correct diagnosis in 66.04% of cases, with a greater proportion of errors for female (54.17%) than male (17.24%) mandibles. Osteometric measurements were able to assign sex correctly in 72.2% in the best of cases (mandibular height), a proportion similar to that obtained using a discriminant function (71.2%). By logistic regression analysis, ramus breadth, index ramus breadth/ramus height and mandibular length were the parameters independently related with a mistaken diagnosis of female sex, whereas bigonial width, ramus height and mandibular length were the parameters more closely and independently related to a mistaken diagnosis of male sex. In conclusion, diagnosis based on visual examination of the mandible or on its metric measurement only serves to roughly estimate sex with an accuracy of around 70% or less, at least among the prehispanic population from Gran Canaria. Amplification of amelogenin alleles leads to unambiguous identification of male and female alleles in 73.68% of cases, at least among the prehispanic population from Gran Canaria.     

A DNA test for sex identification in cattle confirms osteometric results

It is of vital importance to be able to sex identify cattle remains to understand the strategies and importance of cattle husbandry in an ancient society. This is usually done from osteoarchaeological assemblages and often relies on measurements of metapodials. The breadth measurement of the distal trochlea is considered an easy way to identify the sex. Bones from males appears to be easily distinguishable from female counterparts, although it has been complicated to find an external control for the morphological results. Here we investigate the reliability of these particular morphometrics for sex identifying cattle bones with molecular genetics. We use a sex discriminating single nucleotide polymorphism in the ZFXY gene and we apply it to DNA from the bones. To keep the fragment size short and suitable for ancient DNA we base the test on a SNP. The test confirms the osteological sex identification in all cases were DNA could be retrieved. This molecular method can also be used when no fragments suitable for osteological sex identification can be found or when the measurements are non-conclusive.     

A system for classification and description of the horn cores of cattle from archaeological sites

A system is proposed for the classification and sexing of the horn cores of cattle recovered from archaeological sites. The cores are first divided into four groups depending on their length. The terms “small”, “short”, “medium” and “long horned” are given to these groups but bear no relation to the names used for modern breeds of cattle. After differentiation according to length, the sex of the core is designated by visual appraisal of the shape, curvature and angle of attachment of the cores to the frontal bones. It is not claimed that the sex of individual horn cores can always be established but from the sample of 80 cores that we tested by statistical analysis (presented in an appendix) it was evident that the categories based on length and assessment of sex did separate out as expected.     

DNA in cremated bones from an early bronze age cemetery cairn

The discovery of polymeric DNA in charred wheat grains and other burnt plant remains prompted us to examine a set of cremated bones for the presence of ancient DNA. Extracts of cremated bones from an early Bronze Age cemetery cairn were analysed by hybridization probing and the polymerase chain reaction. Hybridization with two probes targeting human DNA resulted in strong positive signals. Polymerase chain reactions directed at a multicopy sequence in human nuclear DNA were successful, extracts of five burials giving amplification products of the expected size. Exploitation of ancient DNA in cremated bones could be of great value in archaeology as it may enable information pertaining to sex and kinship to be obtained from fragmented material.     

A new approach to sexual diagnosis in past populations. Practical adjustments from Van Vark's procedure

Determination of sex is a key aspect in the study of past populations. Bias in skeletal sexing is well known, however, and depends upon the completeness of the skeletal remains and the representativeness of reference samples. In order to correct these difficulties, the authors propose practical adjustments to Van Vark's well‐known procedure. Two fundamental aspects are considered to reduce the bias of sex allocation. First, we propose to increase the effectiveness of sexing during the first step (primary diagnosis only from the pelvic bone). Second, to improve the final step (secondary diagnosis from the extra‐pelvic skeleton), we consider posterior probabilities as essential. These two practical adjustments are successfully tested in a sample of known sex and lead to a classification with 94.5% accuracy. These results significantly improve sex determination in archaeological samples and therefore contribute to a better understanding of past populations. Copyright © 1999 John Wiley & Sons, Ltd.     

Is X-ray diffraction able to distinguish between animal and human bones?

The possibility of determining the human or animal origin of bones from the lattice parameters of their inorganic bioapatite phase, when subjected to a high temperature treatment using the powder X-ray diffraction (XRD) technique, has been explored on a wide number of specimens. Forty-two animal bones were treated in a furnace at 1100 °C for 36 min and compared to 53 cremated human bones from a range of ancient necropolises. The X-ray diffraction patterns of bioapatite were simulated using both monoclinic P21/b and hexagonal P63/m structures to verify any occurrence of phase transformation and any difference in the lattice parameters due to the model. It was determined that the differences between the a-axis and c-axis of the monoclinic and hexagonal lattice were unimportant. Some outlying values were revealed to be caused by the presence of chlorine ions diffused into the apatite structure increasing its average unit cell values. Nevertheless, our results clearly show that in terms of lattice parameters the variability of human specimens are completely overlapped by the non-human variability making the use of XRD in order to distinguish animal from human bones questionable.     

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones.     

A case of valgus ankle in an early Pleistocene hominin

Bipedal locomotion is a defining character of the hominin lineage. A skeletal correlate of bipedality is a perpendicularly oriented tibia relative to the plane of the ankle joint, positioning the foot directly under the centre of mass. Non‐human primates, in contrast, possess a tibial shaft that tilts laterally away from the plane of the ankle joint (valgus ankle), which positions the foot in inversion and is adaptive for arboreal climbing. KNM‐ER 2596 is a small distal tibia from 1.9 mya sediments at Koobi Fora, Kenya. Though it possesses some morphologies functionally linked to bipedality, such as an expanded metaphysis, it also possesses a valgus tilt to the ankle. We test the competing hypotheses that the KNM‐ER 2596 tibia is from a cercopithecoid, a non‐human hominoid, or a pathological hominin. A survey of the orthopaedic literature and a comparative study of modern human and non‐human primate tibiae support the hypothesis that KNM‐ER 2596 is from a hominin. In order to investigate the non‐phylogenetic causes of valgus ankle, we examined human skeletal tibiae with valgus tilt secondary to fracture of the distal fibula. Untreated breaks of the lower third portion of the fibula during childhood can result in a valgus tilt to the distal tibia and occasionally other peculiar morphologies found in the KNM‐ER 2596 tibia such as a superoinferiorly atrophied medial malleolus. The morphology of this tibia is incompatible with hypotheses that it is from a cercopithecoid or a hominoid, and instead, we suggest that KNM‐ER 2596 belonged to a hominin that may have suffered a fracture of the lower left fibula as a juvenile. Copyright © 2010 John Wiley & Sons, Ltd.     

Black grouse as the prey of the golden eagle at an archaeological site

Remains of black grouse, Lyrurus tetrix, were recovered from an archaeological excavation of the site of a golden eagle, Aquila chrysaetos, eyrie. It has been suggested that bird remains from human predation can be distinguished from those due to avian predation, because humans leave few of the distal bones (tibiotarsus, carpometacarpus). In this case, the eagle also left few of these bones; it is suggested that the distinction is one which may allow owl prey to be distinguished, but human and raptor prey are indistinguishable by that criterion.