Postcranial Skeletal Elements Research Articles

Exceptionally preserved shark fossils from Mexico elucidate the long-standing enigma of the Cretaceous elasmobranch Ptychodus.

The fossil fish Ptychodus Agassiz, 1834, characterized by a highly distinctive grinding dentition and an estimated gigantic body size (up to around 10 m), has remained one of the most enigmatic extinct elasmobranchs (i.e. sharks, skates and rays) for nearly two centuries. This widespread Cretaceous taxon is common in Albian to Campanian deposits from almost all continents. However, specimens mostly consist of isolated teeth or more or less complete dentitions, whereas cranial and post-cranial skeletal elements are very rare. Here we describe newly discovered material from the early Late Cretaceous of Mexico, including complete articulated specimens with preserved body outline, which reveals crucial information on the anatomy and systematic position of Ptychodus. Our phylogenetic and ecomorphological analyses indicate that ptychodontids were high-speed (tachypelagic) durophagous lamniforms (mackerel sharks), which occupied a specialized predatory niche previously unknown in fossil and extant elasmobranchs. Our results support the view that lamniforms were ecomorphologically highly diverse and represented the dominant group of sharks in Cretaceous marine ecosystems. Ptychodus may have fed predominantly on nektonic hard-shelled prey items such as ammonites and sea turtles rather than on benthic invertebrates, and its extinction during the Campanian, well before the end-Cretaceous crisis, might have been related to competition with emerging blunt-toothed globidensine and prognathodontine mosasaurs.

Implications in Forensic Medicine - an Exploratory Lumbar Spine Analysis of Sex and Age for the Romanian Population

The attribution of biological sex and age are important aspects in forensic medicine investigations in establishing the identity of unknown skeletal remains. Where remains are incomplete or have been compromised by damage or fragmentation, this can affect the accuracy to which sex and age can be determined and require the development of other tecniques using different bone elements or isolateed bone elements. The objective of the paper was to conduct a descriptive and inferential analysis on certain parameters studied on the lumbar spine with implication in estimating sex and age. The present study used 149 images of magnetic resonance of the vertebral lumbar column, on which the authors perfomed a large-scale analysis of three parameters measured on the RM images from a modern Romanian population. The results of the study found that mostly all variables analysed are involved in evaluation of sexual dismorphism. Regarding age prediction, in this study we conclude that some analyzed parameters are important in providing significant age differences. The present work is a novelty in the field and brings more originality, as it took into account all 5 lumbar vertebrae. The lumbar vertebrae can reliably providing an additional element to the growing list of postcranial skeletal elements that can aid in developing the biological profile of unidentified human remains. However, we need further studies with a larger number of images and to derive population-specific discriminant and regression functions.

A Prognathodontin Mosasaur from the Maastrichtian of the Dakhla Oasis, Western Desert, Egypt

Mosasaurs were diverse in the Upper Cretaceous in Africa, but relatively little is known about the mosasaur fauna of Egypt. Here, associated teeth and postcranial skeletal elements are reported for a mosasaur from the Maastrichtian Dakhla Shale of the Dakhla Oasis. The specimen includes tooth crowns, cervical, dorsal, and caudal vertebrae, and ribs. Teeth and bones exhibit features allowing referral to Prognathodontini. The teeth are relatively straight and blunt, suggesting affinities with Prognathodon overtoni or P. currii. Prognathodontins were important predators in the Maastrichtian of Africa, previously being recorded in Morocco, Congo, and Angola.

Morphometric classification of kangaroo bones reveals paleoecological change in northwest Australia during the terminal Pleistocene

Specimen identification is the backbone of archeozoological research. The challenge of differentiating postcranial skeletal elements of closely related wild animals in biodiverse regions can prove a barrier to understanding past human foraging behaviours. Morphometrics are increasingly being employed to classify paleozoological animal remains, however, the potential of these methods to discriminate between wild animal groups has yet to be fully realised. Here we demonstrate the applicability of a traditional morphometric approach to taxonomically classify foot and ankle bones of kangaroos, a large and highly diverse marsupial family. Using multiple discriminant analysis, we classify archaeological specimens from Boodie Cave, in northwest Australia and identify the presence of two locally extinct macropod species during the terminal Pleistocene. The appearance of the banded hare-wallaby and northern nail-tail wallaby in the Pilbara region at this time provides independent evidence of the ecological and human responses to a changing climate at the end of the last Ice Age. Traditional morphometrics provides an accessible, inexpensive, and non-destructive tool for paleozoological specimen classification and has substantial potential for applications to other diverse wild faunas.

A Baseline for Skeletal Investigations in Medaka (Oryzias latipes): The Effects of Rearing Density on the Postcranial Phenotype.

Oryzias latipes is increasingly used as a model in biomedical skeletal research. The standard approach is to generate genetic variants with particular skeletal phenotypes which resemble skeletal diseases in humans. The proper diagnosis of skeletal variation is key for this type of research. However, even laboratory rearing conditions can alter skeletal phenotypes. The subject of this study is the link between skeletal phenotypes and rearing conditions. Thus, wildtype medaka were reared from hatching to an early juvenile stage at low (LD: 5 individuals/L), medium (MD: 15 individuals/L), and high (HD: 45 individuals/L) densities. The objectives of the study are: (I) provide a comprehensive overview of the postcranial skeletal elements in medaka; (II) evaluate the effects of rearing density on specific meristic counts and on the variability in type and incidence of skeletal anomalies; (III) define the best laboratory settings to obtain a skeletal reference for a sound evaluation of future experimental conditions; (IV) contribute to elucidating the structural and cellular changes related to the onset of skeletal anomalies. The results from this study reveal that rearing densities greater than 5 medaka/L reduce the animals’ growth. This reduction is related to decreased mineralization of dermal (fin rays) and perichondral (fin supporting elements) bone. Furthermore, high density increases anomalies affecting the caudal fin endoskeleton and dermal rays, and the preural vertebral centra. A series of static observations on Alizarin red S whole mount-stained preural fusions provide insights into the etiology of centra fusion. The fusion of preural centra involves the ectopic formation of bony bridges over the intact intervertebral ligament. An apparent consequence is the degradation of the intervertebral ligaments and the remodeling and reshaping of the fused vertebral centra into a biconoid-shaped centrum. From this study it can be concluded that it is paramount to take into account the rearing conditions, natural variability, skeletal phenotypic plasticity, and the genetic background along with species-specific peculiarities when screening for skeletal phenotypes of mutant or wildtype medaka.

Sex estimation in a Turkish population using Purkait’s triangle: a virtual approach by 3-dimensional computed tomography (3D-CT)

Sex estimation is considered one of the first steps in the forensic identification process. Morphological and morphometrical differences between males and females have been used as means for morphoscopic and metric methods on both cranial and postcranial skeletal elements. When dry skeletal elements are not available, virtual data can be used as a substitute. The present research explores 3-dimensional (3D) scans from a Turkish population to test a sex estimation method developed by Purkait (2005). Overall, 296 individuals were used in this study (158 males and 138 females). Purkait’s triangle parameters were measured on computed tomography (CT) scans obtained from both right and left femora of each patient at the Bakirkoy Dr. Sadi Konuk Training Research Hospital (Istanbul, Turkey). Intra- and inter-observer errors were assessed for all variables through technical error of measurements analysis. Bilateral asymmetry and sex differences were evaluated using parametric and non-parametric statistical approaches. Univariate and multivariate discriminant function analyses were then conducted. Observer errors demonstrated an overall agreement within and between experts, as indicated by technical error of measurement (TEM) results. No bilateral asymmetries were reported, and all parameters demonstrated a statistically significant difference between males and females. Fourteen discriminant models were generated by applying single and combined parameters, producing a total correct sex classification ranging from 78.4% to 92.6%. In addition, over 67% of the total sample was accurately classified, with 95% or greater posterior probabilities. Our study demonstrates the feasibility of 3D sex estimation using Purkait’s triangle on a Turkish population, with accuracy rates comparable to those reported in other populations. This is the first attempt to apply this method on virtual data and although further validation and standardisation are recommended for its application on dry bone, this research constitutes a significant contribution to the development of population-specific standards when only virtual data are available. Key points CT analysis using Purkait’s triangle is a suitable tool for assessment of sex in unidentified individuals. The best overall estimation rate was achieved with the F11 model, with around 92% of accuracy. The results suggested 78.4% to 92.6% correct sex identification rates. More research is needed to expand the sample set and verify the results.

Skeletal Osteology of the Lacertid Lizards <i>Phoenicolacerta laevis</i> (Gray, 1838) and <i>Phoenicolacerta cyanisparsa</i> (Schmidtler et Bischoff, 1999) (Squamata: Lacertidae)

The adult skeletons of lacertid lizards Phoenicolacerta laevis and P. cyanisparsa are described based on cleared-and-stained specimens. In comparison with each lacertid species, there are remarkable differences in both cranial and postcranial bones. These are the shape of some cranial bones such as the premaxilla, nasal, quadrate, squamosal, jugal and dentary and the shape of the ischium and ischio-pubis opening and the number of the last presacral vertebrae with small ribs for the postcranial skeletal elements. These detailed descriptions provide as a model to compare lacertid lizards and contribute to understand squamate osteology for further studies.

Hanseatic fish trade in the North Atlantic: evidence of fish remains from Hanse cities in Germany

This paper reviews the evidence for the Hanseatic fish trade in the North Atlantic from the perspective of the consumer sites: the Hanse cities in Germany. Stockfish, the most important good in the North Atlantic trade, are discussed from an archaeozoological perspective. The evidence from Hanse cities accumulated thus far is presented and evaluated. The amount of fish remains analysed from Hanse cities in Germany is still very low, which precludes in-depth research and wider conclusions. Nevertheless, overall patterns appear that are generally consistent with the assumptions of patterns for imported stockfish: high frequencies of Gadidae among the fish remains of coastal Hanse cities, overrepresentation of postcranial skeletal elements, prevailing remains of large size classes, and isotopic data supporting the hypothesis.

Domestication and large animal interactions: Skeletal trauma in northern Vietnam during the hunter-gatherer Da But period.

The aim of this paper is to test the hypothesis that healed traumatic injuries in the pre-Neolithic assemblage of Con Co Ngua, northern Vietnam (c. 6800–6200 cal BP) are consistent with large wild animal interactions prior to their domestication. The core sample included 110 adult (aged ≥ 18 years) individuals, while comparisons are made with an additional six skeletal series from Neolithic through to Iron Age Vietnam, Thailand, and Mongolia. All post cranial skeletal elements were assessed for signs of healed trauma and identified cases were further x-rayed. Crude trauma prevalence (14/110, 12.7%) was not significantly different between males (8/52) and females (5/37) (χ2 = 0.061, p = 0.805). Nor were there significant differences in the prevalence of fractured limbs, although males displayed greater rates of lower limb bone trauma than females. Further, distinct from females, half the injured males suffered vertebral fractures, consistent with high-energy trauma. The first hypothesis is supported, while some support for the sexual divisions of labour was found. The prevalence and pattern of fractured limbs at CCN when compared with other Southeast and East Asian sites is most similar to the agropastoral site of Lamadong, China. The potential for skeletal trauma to assess animal trapping and herding practices prior to domestication in the past is discussed.

Contributions of the pars lateralis, pars basilaris and femur to age estimations of the immature skeleton within a South African forensic setting

Dental development and eruption sequences have prevailed as the gold standard in age estimations of previously unidentified immature individuals within a legal context. However, in the absence of the dentition, skeletal assessments have served as a frequently applied alternative. While various cranial and postcranial skeletal elements have been used in estimating age of the immature skeleton, little is known about the anthropometric value of the pars basilaris, pars lateralis and femur as skeletal age estimation tools. Thus, this study aimed to assess if these bones of the immature human skeleton were useful elements in estimating the age of prenatal and postnatal individuals. These bones were excised from the remains of 74 unclaimed human immature individuals and evaluated using traditional anthropometric methods. The study sample was sourced from the Johannesburg Forensic Pathology Services (JFPS) and the Johannesburg Forensic Paediatric Collection (JFPC), University of the Witwatersrand and subdivided into an early prenatal (younger than 30 gestational weeks); late prenatal (30 to 40 gestational weeks) and postnatal (birth to 7.5months) age ranges. Statistically significant differences (p ≤0.05) were found when assessing the maximum length, sagittal length, maximum width and distal width of the bones across each of the age ranges (30 gestational weeks to 7 postnatal months). The cranial and postcranial skeletal elements investigated in this study provide a valuable contribution to skeletal ageing in African individuals.

A lungfish survivor of the end-Devonian extinction and an Early Carboniferous dipnoan radiation

Until recently the immediate aftermath of the Hangenberg event of the Famennian Stage (Upper Devonian) was considered to have decimated sarcopterygian groups, including lungfish, with only two taxa, Occludus romeri and Sagenodus spp., being unequivocally recorded from rocks of Tournaisian age (Mississippian, Early Carboniferous). Recent discoveries of numerous morphologically diverse lungfish tooth plates from southern Scotland and northern England indicate that at least 10 dipnoan taxa existed during the earliest Carboniferous. Of these taxa, only two, Xylognathus and Ballgadus, preserve cranial and postcranial skeletal elements, which have yet to be described. Here we present a description of the skull of a new genus and species of lungfish, Limanichthys fraseri gen. et sp. nov., which hails from the very earliest Tournaisian in the Ballagan Formation of Burnmouth, southern Scotland. The new specimen represents the earliest definitive Tournaisian lungfish skull material, thus providing an invaluable insight into the response of this group – and, indeed, Sarcopterygii as a whole – immediately following the latest Devonian Hangenberg event. Phylogenetic analysis places Limanichthys fraseri within the Devonian ‘phaneropleurid-fleurantiid’ grade of lungfish and shows that the Carboniferous lungfish represent forms that have their origins deep in the Middle and Late Devonian as well as those from a unique Carboniferous radiation. http://zoobank.org/urn:lsid:zoobank.org:pub:101FFE43-42D5-4950-9169-A900113B6F1D

Testing the effectiveness of osteometrics in the identification of North American gallinaceous bird post-cranial elements

Galliformes, or game birds, are an order of birds commonly utilized by people and are regularly found in zooarchaeological assemblages. Morphological and size similarities make many galliforms difficult to distinguish from each other, thereby prohibiting specific identification of these taxa. Non-identified bones lead to a decrease in information available about archeological sites, particularly for bird species which provide a wealth of information about the economy and environment of historic and prehistoric sites. In this paper, we test the effectiveness of osteometrics in nine North American gallinaceous species to assess their utility for identifying post-cranial skeletal elements to genus or species. Statistical analysis of measurements successfully separated several Phasianidae subfamilies and identified the largest (turkey) and smallest (quail) species. Measurements driving variation between taxa were primarily long bone length and epiphyseal breadth. Few elements showed statistically significant differences within Tetraoninae and Phasianinae clades. We suggest that zooarchaeologists adopt long bone metrics as a standard, complementary technique to traditional morphological identifications for unknown galliforms.

Standardized anthropological measurement of postcranial bones using three-dimensional models in CAD software

This study introduces a standardized protocol for conducting linear measurements of postcranial skeletal elements using three-dimensional (3D) models constructed from post-mortem computed tomography (PMCT) scans. Using femoral DICOM datasets, reference planes were generated and plane-to-plane measurements were conducted on 3D surface rendered models. Bicondylar length, epicondylar breadth, anterior-posterior (AP) diameter, medial-lateral (ML) diameter and cortical area at the midshaft were measured by four observers to test the measurement error variance and observer agreement of the protocol (n=6). Intra-observer error resulted in a mean relative technical error of measurement (%TEM) of 0.11 and an intraclass correlation coefficient (ICC) of 0.999 (CI=0.998–1.000); inter-observer error resulted in a mean %TEM of 0.54 and ICC of 0.996 (CI=0.979–1.000) for bicondylar length. Epicondylar breadth, AP diameter, ML diameter and cortical area also yielded minimal error. Precision testing demonstrated that the approach is highly repeatable and is recommended for implementation in anthropological investigation and research. This study exploits the benefits of virtual anthropology, introducing an innovative, standardized alternative to dry bone osteometric measurements.

Turtles From an Arkadelphia Formation—Midway Group Lag Deposit (Maastrichtian—Paleocene), Hot Spring County, Arkansas, USA

The Arkadelphia Formation—Midway Group (Maastrichtian—Paleocene) contact near Malvern, Arkansas preserves a K-Pg boundary assemblage of turtle species consisting of skull, shell, and non-shell postcranial skeletal elements. The Malvern turtles are preserved within a coquina lag deposit that comprises the basalmost Midway Group and also contains an abundance of other reptiles, as well as chondrichthyans, osteichthyans, and invertebrates. This coquina lag deposit records a complex taphonomic history of exhumation and reburial of vertebrate skeletal elements along a dynamic ancestral shoreline in southwestern Arkansas during the late Cretaceous-early Paleocene. Based on stratigraphic occurrence, the Malvern turtle assemblage indicates that these marine reptiles were living at or near the time of the K-Pg mass extinction and represent some of the latest Cretaceous turtles yet recovered from the Gulf Coastal Plain of the United States.

Hadrosaurian dinosaurs from the Maastrichtian Javelina Formation, Big Bend National Park, Texas

AbstractRare remains of hadrosaurian dinosaurs previously reported from the Maastrichtian Javelina Formation of West Texas had been attributed tentatively to either Edmontosaurus or Kritosaurus. Three recently recovered specimens include substantial skull parts and postcranial skeletal elements sufficient to recognize three distinct hadrosaurs. Two species are found in the lower part of the Javelina Formation; one of these is identified as Kritosaurus sp., confirming the earlier referral of specimens to this taxon. The most complete of these specimens combines features thought to be diagnostic of both K. navajovius Brown, 1910 and ‘Naashoibitosaurus’ ostromi Hunt and Lucas, 1993 and exhibits some unique attributes such that its specific identity remains uncertain. A second species, documented by a single specimen found near the base of the Javelina Formation, is inadequate to confidently identify but appears to represent a ‘solid-crested’ saurolophine with frontals having upturned processes along the midline, similar to those that brace the posterior side of the narial crest in Saurolophus. A third hadrosaur is represented at a bonebed in the uppermost part of the Javelina Formation. Its remains are sufficient to justify designation as a new species ?Gryposaurus alsatei. The skull roof elements are similar to those in species of Gryposaurus, and although no parts of the narial crest are preserved, the bordering elements indicate that ?G. alsatei was a ‘flat-headed’ saurolophine. Referral of ?G. alsatei to Gryposaurus would constitute a significant temporal range extension for the genus into late Maastrichtian time, and if correct, this long-lived lineage of hadrosaurs persisted nearly to the end of Cretaceous time in West Texas. ?G. alsatei was a contemporary of Edmontosaurus, the sole terminal Cretaceous hadrosaur in the northern Great Plains region, and neither possessed the ornate narial crest that characterized many earlier hadrosaurs.

New insights from bone microanatomy of the Late Triassic Hyperodapedon (Archosauromorpha, Rhynchosauria): implications for archosauromorph growth strategy

AbstractBone microanatomy of multiple postcranial skeletal elements of several individuals of Hyperodapedon collected from India is reported. This reveals that fibrolamellar bone tissue is predominant in the mid‐ and inner cortices, whereas the peripheral region of the cortex is composed of either parallel‐fibred and/or lamellar bone. The pattern of primary osteons mostly ranges between laminar and subplexiform. Such predominance of fibrolamellar bone tissue in the cortex suggests an overall fast growth, which slowed down considerably later in ontogeny. Four distinct ontogenetic stages are identified based on the bone microstructure. During the juvenile stage, growth was fast and continuous, but it became punctuated during the early and late sub‐adult stages. In adult individuals, growth was slow and showed periodic interruption but did not stop completely, suggesting that Hyperodapedon had an indeterminate growth strategy. Interelemental histovariations affecting cortical thickness, organization of the vascular network, incidence of growth rings and extent of secondary reconstruction are noted. Throughout ontogeny, the femora show higher cortical thickness than humeri and tibiae, suggesting differential appositional growth rate between the skeletal elements. Differences in cortical thickness are noted in the ribs, which suggest differential functional constraints based on anatomical site‐specific occurrences. Although fibrolamellar bone tissue became progressively more dominant towards the archosaurs, there are considerable variations in the growth patterns of the archosauromorphs. This is exemplified by the bone microstructure of Hyperodapedon, which deviates from the generalized slow‐growth pattern proposed for all basal archosauromorphs, suggesting that rapid growth was already present in the archosauromorphs. The cortical thickness of various long bones of Hyperodapedon bears similarity with that of several extant terrestrial quadrupeds, suggesting that Hyperodapedon was essentially a terrestrial quadruped.

Skeletal trauma in the burials from the royal church of St. Mary in medieval Oslo

AbstractThe considerable collection of skeletal remains from the royal Church of St. Mary (c.1050–1540 AD) in Oslo constitutes part of The Schreiner Collection at the Department of Anatomy, University of Oslo. The remains reveal a high incidence of skeletal trauma, especially injuries caused by sharp‐edged weapons and extensive violence. Evidence of sharp force trauma was primarily observed on the crania. There were a surprisingly few injuries on postcranial skeletal elements. The injuries were mostly observed on middle‐aged and older men, but also on women and subadults. Some of these injuries may be linked to the civil wars in Norway during the 12th and 13th centuries. In most cases, the trauma distribution pattern suggests standardized fighting techniques. Copyright © 2010 John Wiley & Sons, Ltd.

Anatomy of the postcranial skeleton of “Miacis” uintensis (Mammalia: Carnivoramorpha)

ABSTRACT This paper provides the first detailed description of the only known postcranial skeletal elements of “Miacis” uintensis. The morphology of the skeleton differs markedly from previously described “miacids” (a paraphyletic assemblage of early fossil carnivoramorphans), invalidating the notion that all “miacids” were very similar in their postcranial morphology and locomotor styles. The majority of the differences indicate an animal less well adapted to an arboreal lifestyle than has been inferred for other early “miacid” carnivoramorphans. A phylogenetic analysis clearly nests “Miacis” uintensis within the paraphyletic array of taxa previously referred to as the “Miacidae,” in a position closer to the crown clade Carnivora than is Vulpavus, a “miacid” whose postcranium has been previously described. When compared with the early canid Hesperocyon, this specimen shares many features thought to relate to the acquisition of a more terrestrial mode of life. This result indicates that, in contrast to prior models suggesting arboreality for all “miacids,” at least one independent ‘descent from the trees’ occurred much earlier within the array of stem carnivoramorphan taxa.

Doves (Columbidae) and Cuckoos (Cuculidae) from the Early Miocene of Florida

A new genus, Arenicolumba (Aves: Columbiformes: Columbidae), is proposed for the fossil species Columbina prattae Becker and Brodkorb, 1992. This small dove is known from many hundreds of fossils, representing all major post-cranial skeletal elements, from the early Miocene (ca. 18.5 Ma; Hemingfordian land mammal age) Thomas Farm local fauna, Gilchrist County, Florida. Except for the single humerus of Gerandia from the Aquitanian (early Miocene; ca. 22 Ma) of France, Arenicolumba prattae is the oldest known member of the family Columbidae. The nearest living relatives of Arenicolumba appear to be the African genera Oena and Turtur. Thomasococcyx philohippus, new genus and species (Aves: Cuculiformes: Cuculidae), is also described from the Thomas Farm local fauna. Neotropical ground-dwelling cuckoos in the genera Morococcyx, Tapera, Geococcyx, and Dromococcyx may be the closest living relatives of Thomasococcyx. Along with Cursoricoccyx from the Hemingfordian of Colorado, Thomasococcyx philohippus provides evidence that the subfamily of New World ground-dwelling cuckoos (Neomorphinae) existed by the early Miocene.

AMPHIBIANS FROM THE MIDDLE JURASSIC BALABANSAI SVITA IN THE FERGANA DEPRESSION, KYRGYZSTAN (CENTRAL ASIA)

Abstract: Larval and metamorphosed Ferganobatrachus riabinini (Temnospondyli, Brachyopoidea), metamorphosed Kokartus honorarius (Caudata, Karauridae), an indeterminated karaurid (Karauridae indet.) and, presumably, anurans (?Anura indet.) are represented by isolated cranial and postcranial skeletal elements in the Middle Jurassic (Bathonian–Callovian) Balabansai Svita of the Fergana Depression, Kyrgyzstan. The Balabansai vertebrate assemblage is one of the few faunas in which non‐lissamphibian temnospondyls, stem caudates and anurans occur together. The presence of a supraglenoid foramen and a complex strap‐like glenoid on the scapulocoracoid in Kokartus supports its basal phylogenetic position within the Caudata.