Postcranial Elements Research Articles

Comparative taphonomy of Kem Kem Group (Cretaceous) pterosaurs of southeast Morocco

Although diverse, disparate, widespread, and long-lived, our understanding of pterosaurs is heavily biased by specimens from Konservat-Lagerstätten. Here we consider the pterosaur assemblage of the mid-Cretaceous Kem Kem Group of southeast Morocco and compare its taphonomy to other Cretaceous pterosaur-bearing assemblages. The Kem Kem Group pterosaur bones are usually fragmentary and isolated but preserved three-dimensionally, with excellent preservation of macroscopic internal structures and bone histology at ultrastructural levels. The pterosaur assemblage is dominated by azhdarchoid jaw fragments, all anterior of the nasoantorbital fenestra and divergence of the mandibular rami. Post-cranial elements are much rarer with a striking lack of syncarpals, despite being some of the most robust elements of the skeleton. Comparisons with similar deposits in the United Kingdom, Uzbekistan and USA suggest that this relative skeletal abundance is unusual for pterosaur assemblages. The overabundance of jaw material in the Kem Kem Group is likely the result of a combination of factors including the inherent mechanical strength of the jaws, selective predation and scavenging and transportation/hydrodynamic sorting of some elements. The Kem Kem Group should be considered a Konzentrat-Lagerstätte due to the high abundance of vertebrate material. Despite the fragmentary nature of the material, it has excellent preservation of internal structures at macroscopic and microscopic scales. The Kem Kem Group pterosaur assemblage is among the most species diverse known, but taphonomic processes and biases likely obscure its true diversity.

Intraindividual variability of the histological, chronological and growth patterns in post-cranial elements of Liaoningvenator curriei (Paraves: Troodontidae)

ABSTRACT A comprehensive description of the histology of 10 postcranial bones taken from Liaoningvenator curriei (holotype: DNHM D3012) is presented. Corresponding bone samples were sectioned to a thickness of 30 micrometres. The sections were then examined using transmitted and crossed-polarised light microscopes and photographed using an adapted camera and associated capture software. The study reveals that DNHM D3012 was a subadult approaching adulthood, certainly in its fifth year at the time of death. The comparisons of the different sections revealed that in L. curriei (DNHM D3012), the bones from forelimb elements grew faster than those from hind limb elements, this growth strategy likely being linked to its ground-dwelling locomotion. Interspecific comparisons with those other deinonychosaurs and basal avialans suggest that L. curriei (DNHM D3012) exhibits a transitive growth pattern between basalmost, smaller forms of troodontid, and more derived forms that got larger by extending the period of fast growth.

First record of a complete humerus of Agriotherium (mammalia-ursidae) from the early-late Hemphillian of Zacatecas, Mexico

A complete humerus referred to Agriotherium is described, collected from early-late Hemphillian deposits from Zacatecas. Agriotherium is widely represented by isolated molars, mandibles, and maxillae in early-late Hemphillian faunas of Eurasia and North America. In the literature, postcranial elements are scarce and briefly described with little detail. The greatest diversity is known from the Langebaanweg quarry in South Africa; however, the only complete specimen is from Mexico. The proximal end is described, and the humerus shares similarities with the description of the distal end from South Africa, in which the medial epicondyle and crest of the lateral epicondyle are reduced, which can be considered as a limitation in the hunting of larger prey for food. This implies that Agriotherium was not strictly carnivorous but was a predator-scavenger with an omnivorous diet that included plants and fruits.

Redescription of the soft-shell turtle Rafetus bohemicus (Testudines, Trionychidae) from the Early Miocene of Czechia.

The taxonomy of the soft-shell turtle Rafetus bohemicus (Liebus, 1930), family Trionychidae, subfamily Trionychinae, is revised based on new and previously mentioned material (including the type material) from the Early Miocene (Burdigalian, MN 3) sites of the Most Basin, Czechia. Given that the diagnosis was so far based only on plastral elements, here we focused on the cranial material and combined our study with previously published data on postcranial elements. 3D models of the skulls derived from CT scans allow us to provide the first complete skull description of R. bohemicus, including several new cranial diagnostic characters of the species. Our results not only enable the distinction of the trionychid genera Trionyx and Rafetus, both recorded from Central Europe during the Early Miocene, but further allow us to provide an emended diagnosis for R. bohemicus. We confirm the conclusions of a previous study according to which Trionyx pontanus, T. preschenensis, T. aspidiformis, and T. elongatus are nomina dubia. R. bohemicus from Břešt'any (MN 3) represents the oldest record of this genus in Europe as well as the oldest occurrence of the genus.

The postcranial anatomy of the saurolophine hadrosaurid Laiyangosaurus youngi from the upper cretaceous of Laiyang, Shandong, China.

Laiyangosaurus youngi was erected as a saurolophine hadrosaurid on the basis of several cranial elements from the Jingangkou Formation, Wangshi Group, Upper Cretaceous of Laiyang, Shandong, China. The postcranial elements of this taxon are described in detail here, providing additional postcranial characteristics to L. youngi. The phylogenetic analysis included postcranial elements of L. youngi, indicating that L. youngi still lies in the Edmontosaurini clade and no more supplement of postcranial autapomorphy. However, three new postcranial autapomorphies can help distinguish L. youngi from other members of Edmontosaurini: a poorly expanded deltopectoral crest of the humerus, a brevis shelf at the base of the postacetabular process of the ilium, and a well-defined medioventral ridge on the medial side of the postacetabular process. This study is to increase our knowledge on the anatomy and phylogeny of hadrosaurids of Edmontosaurini and provide new valuable evidence for discussing on the taxonomic position and validity of hadrosauroids in the Laiyang Hadrosauroid Fauna.

Intrageneric taxonomic distinction based on morphological variation in the macaque (Macaca) skeleton.

Taxonomic classification is important for understanding the natural world, yet current methods for species assessment often focus on craniodental morphology rather than the entire skeleton. Moreover, it is currently unknown how much variation could, or should, exist intragenerically. Here, we tested whether taxonomy can be accurately predicted based on patterns of morphological variation in macaques (H1 ) and whether postcranial bones reflect subgeneric macaque taxonomy similarly, or better, than the cranium (H2 ). Data included 3D scans of cranial and postcranial bones for eight macaque species (Macaca arctoides, Macaca fascicularis, Macaca fuscata, Macaca mulatta, Macaca nemestrina, Macaca nigra, Macaca radiata, and Macaca sylvanus). Fixed anatomical and semilandmarks were applied to scans of eight skeletal elements (crania = 45; mandible = 31; scapula = 66; humerus = 38; radius = 33; os coxa = 28; femur = 40; tibia = 40). For each skeletal element, regression analyses were performed to minimize the effects of sexual dimorphism. Between-groups principal components analysis was used to visualize the major patterns of among-species morphological variation, while the strength of correct taxon classification was measured with discriminant function analysis. Results suggested accepting the alternate hypothesis that different macaque species can be distinguished morphologically. Both cranial and many postcranial elements appeared to possess a taxonomic signal, and the limb bones-especially the upper limb-are reported to be more useful for taxonomic assessment than previously realized. Theoretically, certain behaviors and/or ecogeographical factors, as well as phylogeny, influenced skeletal morphology in macaques, likely contributing to taxonomic distinctions among different species.

A well preserved pan-pleurodiran (Dortokidae) turtle from the English Lower Cretaceous and the first radiometric date for the Wessex Formation (Hauterivian–Barremian) of the Isle of Wight, United Kingdom

The oldest record of a dortokid turtle (Testudines, Pan-Pleurodira) and the first occurrence of the group in the UK is reported. This find corresponds to the oldest pan-pleurodiran turtle in the country, and the only one from the Mesozoic of the UK. The new specimen, from the Lower Cretaceous (Barremian) Wessex Formation of the Isle of Wight, comprises a relatively complete shell with post cranial elements within a calcite-filled shell vacuity. Micro CT scanning has revealed these tiny bones to include cervical, dorsal and caudal vertebrae, scapulae, pelvic girdle and appendicular elements. In addition, aspects of the internal morphology of the carapace and plastron are revealed. No features allow the new specimen to be distinguished from the coeval Eodortoka morellana of Spain, and we therefore identify it as Eodortoka cf. morellana.The specimen was found ex-situ, and due to questions raised regarding the provenance of the specimen, U–Pb geochronology of the diagenetic calcite filling was performed to establish the age of the specimen. Previously, it has been challenging to determine absolute timing constraints for the Wessex Formation fossil material due to lack of minerals dateable with radiometric techniques. This analysis has thus provided the first radiometric date for the Wessex Formation of 127.3 ± 2.7 Ma.

Sedimentological and stratigraphically controlled preservation styles and distribution of fossil cetaceans from a new Early Miocene fossiliferous locality, Patagonia, Argentina

ABSTRACT Prospecting fieldwork in a new fossiliferous locality of the marine Early Miocene Gaiman Formation (Patagonia, Argentina) results in the discovery of abundant fossil cetaceans (n = 29). We analyse stratigraphic, sedimentologic, palaeontologic, and taphonomic data with the aim of understanding the factors that control the preservation and distribution of these specimens. The cetacean sample is dominated by small odontocetes exhibiting five different preservation categories. Based on sedimentological features, three distinct facies were recognised in the stratigraphic section. Stratigraphically condensed deposits of facies C, related to a ravinement surface and subsequent transgressive deposits, enclose 52% of the specimens, grading from isolated postcranial elements to articulated and associated postcranial and cranial elements. In contrast, facies A and B exhibit predominantly isolated postcranial elements. Facies C shows higher degrees of corrosion, encrustation and fragmentation than those specimens from facies A and B, reflecting differences in preservation quality among the facies. The higher abundance and evidence of long exposure times recorded for facies C seems to be resulted mostly from physico-chemical factors after stratigraphic condensation. Finally, intrinsic biological features and ecological preferences of the specimens could explain the dominance of small-sized odontocetes in a restricted inner shelf to lower shoreface environmental setting.

New postcranial elements of mesonychid mammals from the Ypresian of France: New hypotheses for the radiation and evolution of the mesonychids in Europe

New postcranial elements of mesonychid mammals from the Ypresian of France: New hypotheses for the radiation and evolution of the mesonychids in Europe

Craniofacial pathologies in an early adolescent from the Funnel Beaker site of Modřice, Czechia

Several craniofacial pathologies are present in an early adolescent from a cemetery (n = 22) associated with a Neolithic Funnel Beaker culture in Modřice, Czechia. The objective of the study was to document anomalies on the Modřice 3871 cranium, with an emphasis on investigating whether the mid-sagittal suture exhibited synostosis or bridging to account for the visible scaphocephaly. All available cranial and postcranial elements of the Modřice 3871 early adolescent were examined macroscopically. The cranial vault was subjected to radiography and compared to macroscopic views. Modřice 3871 is estimated to age to 12–14 years. Macroscopic examination and radiography support a diagnosis of mid-sagittal bridging rather than synostosis for this slender and anteroposteriorly elongated cranium. In comparison, the anterior sagittal, coronal and lambdoidal sutures are completely unfused. Craniofacial asymmetry, cribra orbitalia, porotic hyperostosis of the temporal and the presence of multiple wormian bones indicate additional maturational disruptions. The scaphocephaly observed in Modřice 3871 is not severe compared to modern clinical manifestations of craniosynostosis. Radiocarbon dated to 3,700–3,600 years BCE, Modřice 3871 presents one of the oldest recorded cases of scaphocephaly. The elongated vault is probably not the result of head-binding given the dearth of anthropogenic cranial reshaping in the Neolithic of Europe. This study adds to the growing recognition of prehistoric and historic craniofacial anomalies which will likely continue as additional human remains are excavated. In addition, the study increases the understanding of the lived experience of prehistoric individuals experiencing visible craniofacial pathologies such as cranial asymmetry and scaphocephaly.

Locomotor behavior and hearing sensitivity in an early lagomorph reconstructed from the bony labyrinth.

The structure of the bony labyrinth is highly informative with respect to locomotor agility (semicircular canals [SCC]) and hearing sensitivity (cochlear and oval windows). Here, we reconstructed the agility and hearing sensitivity of the stem lagomorph Megalagus turgidus from the early Oligocene of the Brule Formation of Nebraska (USA). Megalagus has proportionally smaller SCCs with respect to its body mass compared with most extant leporids but within the modern range of variability, suggesting that it was less agile than most of its modern relatives. A level of agility for Megalagus within the range of modern rabbits is consistent with the evidence from postcranial elements. The hearing sensitivity for Megalagus is in the range of extant lagomorphs for both low- and high-frequency sounds. Our data show that by the early Oligocene stem lagomorphs had already attained fundamentally rabbit-like hearing sensitivity and locomotor behavior, even though Megalagus was not a particularly agile lagomorph. This is likely because Megalagus was more of a woodland dweller than an open-habitat runner. The study of sensory evolution in Lagomorpha is practically unknown, and these results provide first advances in understanding the primitive stages for the order and how the earliest members of this clade perceived their environment.

A symbolic Neanderthal accumulation of large herbivore crania

This work examines the possible behaviour of Neanderthal groups at the Cueva Des-Cubierta (central Spain) via the analysis of the latter’s archaeological assemblage. Alongside evidence of Mousterian lithic industry, Level 3 of the cave infill was found to contain an assemblage of mammalian bone remains dominated by the crania of large ungulates, some associated with small hearths. The scarcity of post-cranial elements, teeth, mandibles and maxillae, along with evidence of anthropogenic modification of the crania (cut and percussion marks), indicates that the carcasses of the corresponding animals were initially processed outside the cave, and the crania were later brought inside. A second round of processing then took place, possibly related to the removal of the brain. The continued presence of crania throughout Level 3 indicates that this behaviour was recurrent during this level’s formation. This behaviour seems to have no subsistence-related purpose but to be more symbolic in its intent.

Anatomy and phylogenetic affinities of a new silesaurid assemblage from the Carnian beds of south Brazil

ABSTRACT New specimens and the reassessment of many silesaurids have recently shed light on the origin and early evolution of dinosaurs and their close relatives. Yet, the group is relatively poorly represented in South America, an area that likely played an important role in dinosaurian origins. Since the discovery of Sacisaurus agudoensis from the Norian Caturrita Formation, only the fragmentary Gamatavus antiquus and Amanasaurus nesbitti have been reported from the Triassic of south Brazil. Here we describe disarticulated silesaurid remains from Waldsanga, one of the most important tetrapod-bearing localities of the Santa Maria Formation, which represent the second Carnian occurrence of the group in Brazil. The postcranial elements exhibit a combination of dinosauromorph symplesiomorphies and silesaurid diagnostic traits, showing that a conservative anatomy is pervasive among early dinosauromorphs. We also conducted a set of exploratory analyses to infer the phylogenetic relations of the new occurrence and the robustness of some of the most recent phylogenetic hypotheses in face of the increasing diversity of Silesauridae. This revealed a rather uncertain evolutionary scenario not only for Silesauridae, but for early dinosauromorphs in general.

Fishes in the economy of Ancient Greek colonies (600 BC – 300 AD) on the Northern Black Sea Coast – new touches to an old portrait

The article presents the results of a thorough study of fish remains recovered during the excavations of three ancient Greek cities (Olbia, Berezan and Chornomorka) in the northern part of the Black Sea coast. These materials are dated in the range of 600 BC – 300 AC (in the case of Olbia and Berezan), and 500–400 BC for Chornomorka. Fish bones were processed for the identification of species used by the inhabitants of these ancient cities for food. The remains of about ten fish species are present in the studied sample. Of them, sturgeons (Acipenser spp.) were the most numerous in the region at that time. The other species which were usually caught in these ancient Greek cities are mostly represented by carp fishes (roach, common bream, white bream, blue bream, common carp, and crucian carp), but also European catfish Silurus glanis, pike Esox lucius, and pikeperch Sander lucioperca. The weight and size of some fish individuals were reconstructed based on complete bones. Comparison of the specimens from individual samples (series) showed no significant differences in their total length and weight. The economic activity of ancient settlements of the Northern Black Sea region is of interest to archaeologists for a long time. Many of the aspects of this activity, such as agriculture, crafts, and architecture, have been explored quite well (e.g., Christodoulou 2016 and references therein). At the same time, fishery, an important direction of the economy of coastal cities providing a valuable animal protein, often falls out of the scope of research interests. A significant amount of materials collected by archaeologists in the north of the Black Sea coast during the 20th century is still not processed and remains unpublished. Therefore, it is difficult to create a holistic picture of the economy of ancient Greek cities. A valuable information about fishing and fish consumption in ancient cities of the Northern Black Sea region according to archaeological data and osteological collections is presented in Lebedev (1960), Zhiteneva (1964), Hojte (2005), Morales et al. (2007) and Odrin (2010). A few recent publications are focused on the fish osteological material from ancient Greek cities discovered on the Northern Black Sea coast. Archaeozoological studies can show how important fish was in the diet of people, which species were preferred, and how intensive was fishing in this region in different periods. In addition, it is possible to find out whether there was a fish trade between these cities using the ratio of cranial and postcranial elements of the skeleton. Such studies can prove or disprove the statements of Strabo or Herodotus, who wrote about the culinary preferences of ancient Greeks. Therefore, the aim of this article is to present in detail the results of the study of fish bone samples from Olbia, Berezan and Chornomorka in the range from their formation (600 BC) until the end of the Roman period (300 AD). By comparing data from different periods, it is possible to track the role of fishery in the economy of these settlements and its dynamics over time. Key words: Olbia, antiquity, Berezan, archaeozoology, fishing, ancient Greeks, Black Sea

New brevirostrines (Crocodylia, Brevirostres) from the Upper Cretaceous of China

A new alligatoroid, Eurycephalosuchus gannanensis gen. et sp. nov. and an undetermined brevirostrine, Brevirostres gen. et sp. indet. are described. They are preserved together in the Upper Cretaceous of Jiangxi Province, China. Eurycephalosuchus gannanensis is established based on a well-preserved skull with the mandible and some postcranial elements, and Brevirostres gen. et sp. indet. is represented by the right scapula and coracoid. Eurycephalosuchus gannanensis is assigned to Alligatoroidea and phylogenetically nested within a sub-group of Orientalosuchina with other four genera from China and Vietnam. Eurycephalosuchus gannanensis differs from all other orientalosuchines primarily in the short and broad appearance of its skull, the abnormally short (anteroposteriorly narrow) skull table, the exclusion of the parietal from the occipital ridge posteriorly, the postdentary part of the mandible much deeper than the anterior part dorsoventrally, the splenial excluded from the mandibular symphysis, and the external mandibular fenestra small and nearly vertical in orientation. It is different from Brevirostres gen. et sp. indet. in that the distal end of the scapular blade is relatively broader, and the anterior margin of the coracoid is more concave in addition to the smaller size. The discovery of the two new forms not only enriches the diversity of the local fauna but also confirms the monophyly of Orientalosuchina and the Asian dispersal event of the clade after diverging from the mainline rather than a sub-lineage of Alligatoroidea in the Late Cretaceous.

Revisiting the Early Cretaceous sauropod Agustinia ligabuei (Dinosauria: Diplodocoidea) from southern Neuquén Basin (Patagonia, Argentina), with implications on the early evolution of rebbachisaurids

ABSTRACT The Lohan Cura Formation (Albian) at the Cerro de los Leones locality (Neuquén Province, Patagonia, Argentina) yielded several fossil materials, especially sauropod specimens. Among these, Agustinia ligabuei includes postcranial elements of a single individual, with widely debated taxonomy and phylogeny. Here, we provide an extended osteological description and illustrations of the axial and appendicular elements of Agustinia, as well as a revised diagnosis. Moreover, the phylogenetic analysis including a new combination of morphological features recognises Agustinia as a basal Rebbachisauridae, closely related with other South American rebbachisaurids. Our results suggest a more diversified sauropod fauna in the Neuquén Basin, where different members of both neosauropod lineages (i.e. Macronaria and Diplodocoidea) survived in the same region during the Albian age. The reassessment of Agustinia as a basal rebbachisaurid improves our knowledge about the early stages of evolutionary history of Rebbachisauridae, adding new information on the morphological and taxonomic diversification of the clade during the Early Cretaceous of southwestern Gondwana.

Speciated mechanism in Quaternary cervids (Cervus and Capreolus) on both sides of the Pyrenees: a multidisciplinary approach

Cervids, and especially the red deer Cervus elaphus, are among the most regularly and abundantly recorded ungulates in Pleistocene/Paleolithic bone assemblages. Numerous Pleistocene or Holocene subspecies have been described, reinforcing their status as essential proxies for environmental and chronological reconstructions. Despite this, at the beginning of the Late Pleistocene, their diversity seems to have decreased. In this study, we analysed teeth and some postcranial elements of Cervus and Capreolus from north-eastern Iberia and south-eastern France to clarify their morphological characteristics and ecological adaptations. We describe a transitional form in north-eastern Iberia between the western European stock and the current form C. e. hispanicus. Such sub-speciation processes are connected to biogeographical factors, as there were limited exchanges between north-eastern Iberia and the northern Pyrenees, whereas the north-western part of the peninsula seems more connected to the northern Pyrenees. The anatomical plasticity (morpho-functional adaptation and body size) of red deer is connected to dietary flexibility (dental meso- and microwear). Conversely, Capreolus shows greater morphological and ecological homogeneity. Body size variations seem directly correlated with their ability to browse throughout the year. The marked differences between the eco-bio-geographical responses of the two taxa can be explained by their habitat selection.

Ultraviolet Autofluorescence Microscopy of Nanotyrannus lancensis Sections Reveals Blood Clots in Vessel Canals

Abstract: Theropod dinosaurs have captured the imagination of the public and paleontologists alike. Histology of the bones of theropods has revealed much about dinosaur physiology, behavior, and growth. Histology and ultraviolet fluorescence (UVFL) microscopy of one controversial dinosaur, Nanotyrannus lancensis, reveals the presence of blood clots in post-fixed vessel canals of claw, vertebra, and other isolated post-cranial elements collected at Hell Creek, MT. These clots are thicker, more closely adherent to canal walls, and more reactive to 347 nm UVFL incident light than unfixed specimens. Theropod histology images in the literature display similar clots, and those should be subjected to UVFL for confirmation. In addition, nematodes are evidently preserved in vessel canals of dinosaurs.

Skeletal Sex Estimation Methods Based on the Athens Collection

The aim of this paper was to present all studies that have used the Athens Collection in order to develop methods for skeletal sex estimations and highlight the importance of documented skeletal reference collections in forensic anthropology. The Athens Collection is housed at the National and Kapodistrian University of Athens, Greece; it consists of 250 individuals and both sexes are well-represented. Several studies have used this collection for skeletal sex estimations. In particular, macroscopic observation methods have been used based on the cranium and pelvis; metric methods, including geometric morphometrics, have been applied to cranial and postcranial elements. These studies involved both the development of methods for the sex estimation of Greek/Eastern Mediterranean assemblages and an examination of the accuracy of the existing methods, thus making this collection a key resource for forensic anthropological and bioarchaeological research.

A comparative study of the postcranial skeleton of Patagonian and Pampean specimens of the Pleistocene giant sloth genus Mylodon Owen, 1839 (Xenarthra, Pilosa) and its implications

ABSTRACT In this work, we describe postcranial elements of Mylodon listai distributed in collections from Argentina, Chile and Europe. Mylodon listai remains from Patagonia are clearly different from those from the Pampean region (Mylodon darwinii), presenting morphological differences in their postcranium such as a smaller intercondylar space and less displacement of the medial condyle in the femur. These anatomical features reveal that M. listai had less bowed legs than M. darwinii. We propose that this would be an adaptation to a less fossorial lifestyle in their habitats in southern Patagonia without having to do directly with differences in body mass in the southern specimens, because M. listai would have reached similar or even larger sizes than M. darwinii.