Individual Skeletons Research Articles

The thermoregulatory functions of the Triceratops frill and horns: heat flow measured with oxygen isotopes

ABSTRACT Variability of body temperature within fossil vertebrates can be measured by the oxygen isotopie composition of bone phosphate (δp). Intrabone and interbone δp variations indicate heat flow within an individual and can be used to establish thermoregulatory strategies such as homeothermy and regional heterothermy. This method is applied to an individual Triceratops skeleton where the results suggest very high and uniform heat flow through the parietal frill, maintaining mean frill temperatures between 0–4°C below the body core. Heat flow to the postorbital horn-core is much more variable. The frill and horn cores of Triceratops were used as thermoregulatory structures with the horn cores interpreted as being especially important in the stabilization of brain temperatures at extreme ambient temperatures and the frill serving a more consistent role in body temperature regulation.

Variability in osteon size in recent human populations.

The possibility of smaller osteons in the cortical bone of Late Pleistocene human populations begs the question of how these histological features vary within individual skeletons among and between populations. The distributional characteristics of total osteon area (On.Ar) and Haversian canal area (H.Ar) are explored using data from three samples of historically known individuals: ribs and femora from eighteenth-century Huguenots in England (Spitalfields, n = 20), ribs and femora from nineteenth-century British settlers in Canada (St. Thomas, n = 21), and ribs from twentieth-century South African cadavers (University of Cape Town; following curatorial classifications, n = 10 white, 10 black, 10 colored). Neither histological variable is normally distributed. About 96% of the random variation is within the individual bone sample. There are no significant differences between sexes for either variable in any sample, and age has no effect in most instances. Femoral osteons are significantly larger than rib osteons within individuals and across samples. Haversian canal area is more variable than On.Ar, especially in the twentieth-century sample, where within-sample coefficients of variation are frequently >100%. Using modern centiles developed here, some Late Pleistocene long bone samples have On.Ar values below the range of modern variation. Because of ribs' smaller cross-sectional areas and less broadly ranging values for On.Ar, ribs would provide a preferable site for future comparative studies.

Validation of the asteroid Asterias rubens (Echinodermata) as a bioindicator of spatial and temporal trends of Pb, Cd, and Zn contamination in the field

The aim of the present study was to assess the value of Asterias rubens as a bioindicator of metal contamination in the field. Spatial gradients of Pb, Cd, and Zn contamination were identified along Sørfjord, and metal concentrations were consistently higher (1.7–8.3 times) in the body compartments of large asteroids sampled close to the smelters than in those sampled further away. Cd and Pb concentrations in the pyloric caeca varied along the fjord according to a decreasing sigmoidal relationship, while Cd and Pb concentrations in the body wall and the skeleton varied according to a decreasing exponential relationship. This suggests that the bioavailability of these metals has decreased over the last few years at the head of the fjord, which agrees generally with water chemistry data available from the State Pollution Monitoring Programme (Norway). The decrease in metal bioavailability could be a direct consequence of the 1992 remedial action taken in the fjord to reduce heavy metal release from the contaminated sediments. Lead concentrations in the skeletons of large asteroids (12–14cm; 154 ± 63 μg Pb g −1 dry wt) were eight times higher than those in the skeletons of juvenile individuals (0.5–4 cm; 19 ± 8 μg Pb g −1 dry wt) in the population located at the head of the fjord. Asteroids of 12–14 cm length were likely to be 4–7 y old (i.e. born before the remedial action) while small asteroids were born after the remedial action. According to comparisons with allometric relationships in an uncontaminated population and experimental exposures, results indicate that the half-life of Pb in the skeleton is long (i.e. several years) while the half-life of Cd and Zn is much shorter (i.e. several weeks for Cd, and short but not precisely known for Zn). A smaller size and unusual reduction of the skeleton of adult individuals at the head of the fjord were observed and may result from the effects of heavy metal pollution. A comparison between possible sources of contamination in the fjord (metals in water, food, and sediments) indicates that sediment-associated metals are likely to be an important source of contamination in this environment due to the microphagic activity of asteroids.

Inflammatory arthritis in Pongo.

As the arboreal ape, Pongo, has an unusual ground ambulation adaptation, it was of interest to assess the impact of Pongo gait on patterns of arthritis. While osteoarthritis was not identified in Pongo, 11% of individual skeletons were afflicted with an inflammatory, erosive arthritis. The presence of sacroiliac involvement and the nature and distribution of erosive lesions allowed definitive diagnosis of spondyloarthropathy. Character, distribution, and radiologic appearance revealed a picture distinguishable from spondyloarthropathy in other primates.

Bony changes of the glenoid as a consequence of shoulder instability.

Among 500 skeletons of mature individuals, 27 showed signs of shoulder instability as indicated by the presence of a glenoid rim avulsion fracture, a bony Bankart lesion, with an anterior or posterior Hill-Sachs defect. Twenty-two of these glenoid lesions were anterior, and five were posterior. This is a higher prevalence than reported in clinical studies. With few exceptions the pathologic changes in the bony glenoid were well circumscribed and not found in conjunction with diffuse arthritic changes. These findings do not support prophylactic shoulder stabilization to avoid the development of arthritic changes of a generalized and major degree.

A metamorphosed salamander from the early Cretaceous of Las Hoyas, Spain

A salamander, Valdotriton gracilis gen. et sp. nov., is described on the basis of six articulated skeletons of small metamorphosed individuals from the early Barremian (Early Cretaceous) La Huérguina Formation at the locality of Las Hoyas, Cuenca Province, Castilla La Mancha, Spain. Valdotriton is a relatively plesiomorphic member of the Urodela (crown-group salamanders), but more derived than the Sirenidae and Cryptobranchoidea, in that it possesses a single ossification in place of the prearticular and angular, and it has intravertebral spinal foramina on the anterior caudal vertebrae. It represents a plesion on the stem of the ‘internally fertilizing salamander clade’ comprising the Plethodontidae, Amphiumidae, Rhyacotritonidae, Proteidae, Dicamptodontidae, Ambystomatidae and Salamandridae.

A novel fast and reliable thinning algorithm

Abstract In this paper a new algorithm is proposed for skeletonizing binary digital images. The algorithm does not employ the conventional pixel- or non-pixel-based techniques. Instead, it identifies regions of particular shapes in the image and substitutes apppropriate skeleton patterns for them. Initially, as many horizontal and vertical strips as possible are detected. These correspond to rather straight, long and narrow regions in the original image. Any remaining regions correspond to joints between strips. The strips are then grouped into trapezoidal regions which may be replaced by the appropriate skeleton patterns. The individual skeleton patterns are then merged using the skeletons due to the jointing regions, generating the final skeleton. A compact representation is obtained for post-processing, and the issue of robustness with respect to noise is addressed.

Scaphocephaly in a Prehistoric Skeleton from Harappa, Pakistan

Irregularities of cranial suture closure resulting in scaphocephaly are documented for a number of prehistoric and historic human populations of the eastern and western hemispheres, but what may be the first recorded case from southern Asia appeared during the 1987 archaeological field season at the Indus Valley Civilization site of Harappa, Pakistan. The female specimen with this condition also exhibits indicators of developmental abnormalities in the postcranial skeleton. These features are discussed in the context of assessing anatomical and ontogenetical relationships of craniostenostic eccentricities with abnormalities of facial, dental and postcranial regions of the skeletons of scaphocephalic individuals.

Zygapophyseal and costovertebral/costotransverse joints: an anatomic assessment of arthritis impact.

Zygapophyseal articular surface cortical disruption noted radiologically in RA is at variance with the perception that it is an axial joint-sparing (cervical vertebrae excepted) disorder. However, the reliability of such radiologic assessment has been questioned. Direct visual examination of the zygapophyseal and costovertebral joints (of individuals with documented RA, spondyloarthropathy, diffuse idiopathic skeletal hyperostosis and normal controls) allowed these radiologic perceptions to be tested and placed in perspective. Articular surface cortical disruption/discontinuity was actually found to take two forms, indistinguishable by standard X-ray technique: 1. fronts of resorption, with reactive new bone formation; 2. exposed bare trabeculae, secondary to a 'wearing away' abrasion process. Zygapophyseal and costovertebral erosions were only found in skeletons of individuals with spondyloarthropathy, whereas the abrasion-related phenomenon was especially prevalent in RA and in normal controls. Inability to radiologically distinguish abraded or 'worn away' lesions from erosions explains past radiologic confusion. Radiologic evidence of zygapophyseal and costovertebral joint surface disruption/discontinuity does not appear specific for erosive disease.

1H-N.m.r. spectroscopy of O-carboxymethyl derivatives of d-glucose

Carboxymethylation is a common method used to modify the properties of cellulose and starch but, as a rule, not all of the hydroxyl groups are substituted. The products can be regarded as copolymers of unsubstituted, mono(2-, 3-, and 6-), di(2,3-, 2,6-, and 3,6-), and tri-substituted (2,3,6-) D-glucose moieties. Characterisation of the structures of the monomers in a hydrolysate of carboxymethylcellulose, using 13C-n.m.r. spectroscopy’q’and g.l.c.-(e.i.)-m.s.3, has been reported. ‘H-N.m.r. spectroscopy (90 MHz) of hydrolysates of carboxymethylcellulose has been used to determine the distribution of the carboxymethyl groups and the degree of substitution4. However, the low resolution of the ‘H-n.m.r. spectra precluded the assignment of all of the signals. A new procedure for the determination of the distribution of the substituents in carboxymethylcellulose based on the analysis of hydrolysates by high-pH anion-exchange chromatography on CarboPac PA-l with pulsed amperometric detection (h.p.a.e.c.-p.a.d.)5 allowed the isolation of all of the monomers. We now report the complete assignment of the ‘H-n.m.r. spectra of the carboxymethylated derivatives of D-glucopyranose with substituents at O-2, O-3, O-6, O-2,3, O-2,6, O-3,6, and O-2,3,6. Each of the above derivatives was an cc&mixture with various cr&ratios. Most of the resonances of the skeleton protons were assigned by combining information from 2D homonuclear Hartmann-Hahn (HOHAHA) and 1D spectra (Tables I and II). By choosing a suitable mixing time for the 2D HOHAHA spectra, the number of cross-peaks on the individual skeleton proton tracks was limited to one or two. Most of the assignments were deduced from these spectra, using additional information such as intensity differences and coupling patterns. When necessary, 2D HOHAHA spectra were recorded with longer mixing times which showed partial or complete subspectra on the H-l track of each anomer, or 2D doublequantum filtered ‘H-‘H correlation (DQF-‘H-‘H COSY) spectra were taken. The resonances of the skeleton protons that overlapped in the 2D spectra were assigned on the basis of iterative simulation and matching. The signals for the CH,COO groups appeared in a region (8 3.9-4.3) where,

Dentofacial morphology in professional opera singers

The interaction between muscle function and bone development has been studied mainly in animals. The aim of the present investigation was to study the dentofacial skeleton in individuals with a high degree of activity of muscles associated with the facial skeleton. It was assumed that a professional singer would constitute such an individual. Lateral cephalograms of singers from the Royal Opera Choir in Stockholm were studied and compared with lateral cephalograms of a control group. Significant differences between the singers and controls were found, such as length of mandible, length of maxilla, and increased facial height. The findings could be interpreted as an association between facial muscle hyperactivity and respiratory hyperfunction and dentofacial morphology.

Two Methods for reconstructing the empirical mortality profile

This paper goes one step beyond the age determination of the individual skeleton. It presents two methods for the reconstruction of the distribution of the age at death in a sample of skeletons. It is shown that the maximum likelihood method, in spite of certain weaknesses, is superior to the traditionally used proportional method, especially in situations when the analyzed sample consists of skeletons with very different conditions of preservation and thus age intervals of differing lengths. The maximum likelihood method eliminates a bias towards increased average age at death which is introduced by the proportional method. An analysis of an empirical example indicates that the difference between results obtained using the two methods increases with increasing age.

Human skeletons from the Newgate site in the City of London

The graveyard excavated at the Newgate (General Post Office) site in the City of London contained 436 badly damaged individual graves of a medieval Saxon population. Detailed studies of the individual skeletons showed that the population was fairly homogenous with very small range of individual variations. The people were short in stature and were muscular in build. Old individuals were uncommon. One third of women's graves also contained a child. Some congenital deformations, degenerative disease and injuries were noted on the excavated bones. Everyone suffered from severe dental caries, periondontal disease and subsequent loss of teeth. The skeletal features are described and inferences drawn concerning the biological status of the population.

Juveniles of the stegosaurian dinosaurStegosaurusfrom the Upper Jurassic of North America

ABSTRACT Two partial skeletons of juvenile individuals of Stegosaurus with estimated body lengths of about 1.5 m (5 ft) and 2.6 m (8.5 ft) are described from the Morrison Formation (Upper Jurassic) of Utah and Wyoming. These juveniles differ from adults in the absence of fusion in composite bones (sacrum, scapulocoracoid, tibia–fibula–astragalus–calcaneum), the smoothness of the surface of the bones, the smaller size of ridges for muscular attachment, a proportionally more slender and elongate scapula, the relatively small size of the olecranon process of the ulna and the head of the femur, and the possible absence of dermal plates (but tail spines were present). Apart from the ratios of the length of the femur to those of the humerus and ilium, and the form of the scapula, ilium and fibula, the bones of juvenile individuals of Stegosaurus are very similar to those of juvenile individuals of the stegosaur Kentrosaurus (Upper Jurassic, East Africa). A probable sexual dimorphism in the sacrum with either fo...

American archaeology and physical anthropology in historical perspective

AbstractThe historical relationships between archaeology and physical anthropology are discussed, beginning with Morton and extending to the present. The emergence of Boasian anthropology had a fundamental effect on the way skeletal data could be interpreted in archaeological and anthropological contexts. Hooton's influence was responsible for shifting attention from the occasional individual skeleton to large samples, as exemplified by research on collections by Kidder at Pecos. Nevertheless, this and later studies suffered from a typological approach which was replaced in the 1940s by populational concepts of variability and evolutionary change. As archaeologists have come to recognize human behavior as a function of the interdependence of the physical and the cultural in particular instances of environmental adaptation, they require the explication of the physical dimension which the physical anthrologist alone can provide.

Epiphyseal union and dental eruption Macaca mulatta.

Age of dental eruption and epiphyseal fusion is estimated for the permanent dentition and long bone epiphyses of rhesus macaques (Macaca mulatta), with 299 skeletons of individuals with known age of death, from the Cayo Santiago skeletal collection. Epiphyses at a given joint tend to have the same time. While males and females tend to have the same pattern of epiphyseal fusion, females' epiphyses fuse earlier than those of malep rhesus macaques (Macaca mulatta), with 299 skeletons of individuals with known age of death, from the Cayo Santiago skeletal collection. Epiphyses at a given joint tend to have the same time. While males and females tend to have the same pattern of epiphyseal fusion, females' epiphyses fuse earlier than those of males, especially at the elbow and knee joints. The order of epiphyseal fusion in rhesus macaques follows the general primate pattern. Times of dental eruption for males and females are generally the same, except for the relatively late eruption of the canine in the males. The order of eruption follows a common primate pattern (dm2-M1-I1-I2-M2-(P3, P4)-C-M3). Multiple regressions were calculated in order to allow determination of developmental state, or predictions of chronological age, from epiphyseal fusion and/or dental eruption scores in juvenile rhesus macaques. Standard deviations of residuals from these regressions indicate considerable variation in developmental state among animals of the same chronological age. The lack of correlation between residuals from the separate skeletal and dental regressions, indicates that skeletal and dental development are largely independent.

The adult skeleton from the Capsian site of Aïn Misteheyia, Algeria

We describe an adult skeleton excavated in 1976 near Chéria, Algeria, in the context of a Capsian escargotière, associated with an absolute date of 9130 B.P. Analysis suggests a young adult male of moderate robustness and c. 181 cm in height. Comparison with published skeletal material from North Africa in Epipalaeolithic context concludes that the individual falls within the expected range of variation for this temporal period. The problem of assessing the affinity of individual skeletons is discussed.

Radiolarian Preservation in Present and Past Oceans: ABSTRACT

Three methods were used to collect living and recently dead radiolarians and fecal pellets containing radiolarians--plankton tows for those in the water column, and gravity cores and box cores for recovery from surficial sediments. Deep Sea Drilling Project cores were used to study radiolarians from fossil sediments. Our techniques differ from previous studies by the investigation of individual skeletons and suggest that skeletons are removed from the water column primarily by dissolution and, secondarily, by settling as individuals or via fecal pellets. Laboratory experiments suggest that metallic coatings help to protect the skeletons from dissolution in the water column and in sediments. Other factors of extreme importance are differential rates of settling thickness of the radiolarian dissolution zone, productivity of overlying waters, amounts and ratios of terrigenous and authigenic sediment, presence of different water masses in the water column and at the sediment-water interface, degree of bioturbation, and chemical conditions at and below the sediment-water interface. Paleobiologic developments such as the evolution of diatoms appear to be related to conservation. The use of silica by diatoms may be partly responsible for the preferential dissolution of some Neogene radiolarians. Major changes in oceanic circulation appear to be related to such changes as the cessation of preservation in the middle and tropical Atlantic during the middle Miocene. End_of_Article - Last_Page 483------------

Walnut creek massacre: Identification and analysis

AbstractThe purpose of this study is to add to our understanding of skeletal material from the American pioneer period. Eight White and two Negro skeletons were washed out of their graves during flood conditions of 1973, but the recovery and subsequent storage of this material permitted commingling, and identification of the individual skeletons had to be undertaken before the material could be analyzed. Variation in age, sex, race, metric, non‐metric traits and condition of the bone was considered prior to the analysis of the material. When these methods failed, ultra‐violet fluorescence of the material and the matching of individual bones with colour slides taken at the time of the excavation were employed. Identification of all bones for the ten skeletons was impossible. However, on the basis of non‐metric trait variation a father and son pairing is tentatively identified. Analysis of this material shows the early pioneer to have been a rather tall and robust individual displaying little bone pathology, but advanced pathology in the dental tissue and alveolar region. Historical records pertinent to this massacre validate the identification of sex, race, and age for these individuals.

A note on the anthropological characteristics of the Padina population

The evidence presented in this paper suggests that the population at Padina was an original, solitary and homogenous group. There was no evidence that mixture with another racial group had occured. The old, robust, cromagnonoid characteristics prevailed in the morphology of the Padina skulls, but signs of early gracile change in the postcranial bones of the skeletons of most individuals were clear. The Padina population was in a state of transition. Many typical Mesolithic characteristics were disappearing, to be replaced by Neolithic ones. As a result the Padina population is classified as a late Mesolithic, Proto-Dinaric racial group, which developed probably from a cromagnonoid race along the Danube.