New Comparative Data on the Long Bone Microstructure of Large Extant and Extinct Flightless Birds

Here, we investigate whether bone microanatomy can be used to infer the locomotion mode (cursorial vs. graviportal) of large terrestrial birds. We also reexamine, or describe for the first time, the bone histology of several large extant and extinct flightless birds to (i) document the histovariability between skeletal elements of the hindlimb; (ii) improve our knowledge of the histological diversity of large flightless birds; (iii) and reassess previous hypotheses pertaining to the growth strategies of modern palaeognaths. Our results show that large extinct terrestrial birds, inferred as graviportal based on hindlimb proportions, also have thicker diaphyseal cortices and/or more bony trabeculae in the medullary region than cursorial birds. We also report for the first time the occurrence of growth marks (not associated with an outer circumferential layer-OCL) in the cortices of several extant ratites. These observations support earlier hypotheses that flexible growth patterns can be present in birds when selection pressures for rapid growth within a single year are absent. We also document the occurrence of an OCL in several skeletally mature ratites. Here, the high incidence of pathologies among the modern species is attributed to the fact that these individuals were probably long-lived zoo specimens

Biomechanical evolution of solid bones in large animals: a microanatomical investigation

International audienc

Proceedings of Abstracts Engineering and Computer Science Research Conference 2019

© 2019 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Note: Keynote: Fluorescence visualisation to evaluate effectiveness of personal protective equipment for infection control is © 2019 Crown copyright and so is licensed under the Open Government Licence v3.0. Under this licence users are permitted to copy, publish, distribute and transmit the Information; adapt the Information; exploit the Information commercially and non-commercially for example, by combining it with other Information, or by including it in your own product or application. Where you do any of the above you must acknowledge the source of the Information in your product or application by including or linking to any attribution statement specified by the Information Provider(s) and, where possible, provide a link to this licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/This book is the record of abstracts submitted and accepted for presentation at the Inaugural Engineering and Computer Science Research Conference held 17th April 2019 at the University of Hertfordshire, Hatfield, UK. This conference is a local event aiming at bringing together the research students, staff and eminent external guests to celebrate Engineering and Computer Science Research at the University of Hertfordshire. The ECS Research Conference aims to showcase the broad landscape of research taking place in the School of Engineering and Computer Science. The 2019 conference was articulated around three topical cross-disciplinary themes: Make and Preserve the Future; Connect the People and Cities; and Protect and Care

Architecture et liturgie en Normandie au XIe siècle : les transepts

Canoville Jean-Yves. Architecture et liturgie en Normandie au XIe siècle : les transepts. In: Études Normandes, 27e année, n°1-2, 1978. pp. 75-120

New Comparative Data on the Long Bone Microstructure of Large Extant and Extinct Flightless Birds

Here, we investigate whether bone microanatomy can be used to infer the locomotion mode (cursorial vs. graviportal) of large terrestrial birds. We also reexamine, or describe for the first time, the bone histology of several large extant and extinct flightless birds to (i) document the histovariability between skeletal elements of the hindlimb; (ii) improve our knowledge of the histological diversity of large flightless birds; (iii) and reassess previous hypotheses pertaining to the growth strategies of modern palaeognaths. Our results show that large extinct terrestrial birds, inferred as graviportal based on hindlimb proportions, also have thicker diaphyseal cortices and/or more bony trabeculae in the medullary region than cursorial birds. We also report for the first time the occurrence of growth marks (not associated with an outer circumferential layer-OCL) in the cortices of several extant ratites. These observations support earlier hypotheses that flexible growth patterns can be present in birds when selection pressures for rapid growth within a single year are absent. We also document the occurrence of an OCL in several skeletally mature ratites. Here, the high incidence of pathologies among the modern species is attributed to the fact that these individuals were probably long-lived zoo specimens

Microstructure of Vertebrae, Ribs, and Gastralia of Triassic Sauropterygians—New Insights into the Microanatomical Processes Involved in Aquatic Adaptations of Marine Reptiles

International audienc

Systemic distribution of medullary bone in the avian skeleton: ground truthing criteria for the identification of reproductive tissues in extinct Avemetatarsalia

Abstract Background Medullary bone (MB) is an estrogen-dependent, sex-specific tissue produced by female birds during lay and inferred to be present in extinct avemetatarsalians (bird-line archosaurs). Although preliminary studies suggest that MB can be deposited within most skeletal elements, these are restricted to commercial layers or hormonally treated male pigeons, which are poor analogues for wild birds. By contrast, studies in wild bird species noted the presence of MB almost exclusively within limb bones, spurring the misconception that MB deposition is largely restricted to these regions. These disparate claims have cast doubt on the nature of MB-like tissues observed in some extinct avemetatarsalians because of their “unusual” anatomical locations. Furthermore, previous work reported that MB deposition is related to blood supply and pneumatization patterns, yet these hypotheses have not been tested widely in birds. To document the skeletal distribution of MB across Neornithes, reassess previous hypotheses pertaining to its deposition/distribution patterns, and refine the set of criteria by which to evaluate the nature of purported MB tissue in extinct avemetatarsalians, we CT-scanned skeletons of 40 female birds (38 species) that died during the egg-laying cycle, recorded presence or absence of MB in 19 skeletal regions, and assessed pneumatization of stylopods. Selected elements were destructively analyzed to ascertain the chemical and histological nature of observed endosteal bone tissues in contentious skeletal regions. Results Although its skeletal distribution varies interspecifically, we find MB to be a systemic tissue that can be deposited within virtually all skeletal regions, including cranial elements. We also provide evidence that the deposition of MB is dictated by skeletal distribution patterns of both pneumaticity and bone marrow; two factors linked to ecology (body size, foraging). Hence, skeletal distribution of MB can be extensive in small-bodied and diving birds, but more restricted in large-bodied species or efficient flyers. Conclusions Previously outlined anatomical locations of purported MB in extinct taxa are invalid criticisms against their potential reproductive nature. Moreover, the proposed homology of lung tissues between birds and some extinct avemetatarsalians permit us to derive a series of location-based predictions that can be used to critically evaluate MB-like tissues in fossil specimens

Identifying medullary bone in extinct avemetatarsalians : challenges, implications and perspectives

Medullary bone (MB) is a sex-specific tissue produced by female birds during the laying cycle, and it is hypothesized to have arisen within Avemetatarsalia, possibly outside Avialae. Over the years, researchers have attempted to define a set of criteria from which to evaluate the nature of purported MB-like tissues recovered from fossil specimens. However, we argue that the prevalence, microstructural and chemical variability of MB in Neornithes is, as of yet, incompletely known and thus current diagnoses of MB do not capture the extent of variability that exists in modern birds. Based on recently published data and our own observations of MB distribution and structure using computed tomography and histochemistry, we attempt to advance the discourse on identifying MB in fossil specimens. We propose: (i) new insights into the phylogenetic breadth and structural diversity of MB within extant birds; (ii) a reevaluation and refinement of the most recently published list of criteria suggested for confidently identifying MB in the fossil record; (iii) reconsideration of some prior identifications of MB-like tissues in fossil specimens by taking into account the newly acquired data; and (iv) discussions on the challenges of characterizing MB in Neornithes with the goal of improving its diagnosis in extinct avemetatarsalians. This article is part of the theme issue 'Vertebrate palaeophysiology'

Successful Pelvic Resection for Acetabular Hydatidosis

Background. Hydatidosis of the bone is a rare occurrence (0.9 to 2.5% of all localization of the disease). In those occurrences, the pelvic bone is the second most frequent localization. Curative treatment of pelvic bone hydatidosis is difficult and a consensus is yet to be found. Clinical Case. We report a case of hydatidosis of the ischium, extended to the homolateral hip. The patient was treated through hip resection using patient-specific cutting guides, followed by total hip reconstruction. Albendazole was administered to the patient for two months before the surgery and for three months following the surgery. Conclusions. In a young patient, hydatidosis of the pelvic bone can be treated with satisfying results through wide resection of the hip coupled with an antiparasitic treatment administered before and after the surgery. Prosthetic reconstruction, similar to what is done in cancer surgery, restores good functions

Independent Evidence for the Preservation of Endogenous Bone Biochemistry in a Specimen of <i>Tyrannosaurus rex</i>

Biomolecules preserved in deep time have potential to shed light on major evolutionary questions, driving the search for new and more rigorous methods to detect them. Despite the increasing body of evidence from a wide variety of new, high resolution/high sensitivity analytical techniques, this research is commonly met with skepticism, as the long standing dogma persists that such preservation in very deep time (>1 Ma) is unlikely. The Late Cretaceous dinosaur Tyrannosaurus rex (MOR 1125) has been shown, through multiple biochemical studies, to preserve original bone chemistry. Here, we provide additional, independent support that deep time bimolecular preservation is possible. We use synchrotron X-ray fluorescence imaging (XRF) and X-ray absorption spectroscopy (XAS) to investigate a section from the femur of this dinosaur, and demonstrate preservation of elements (S, Ca, and Zn) associated with bone remodeling and redeposition. We then compare these data to the bone of an extant dinosaur (bird), as well as a second non-avian dinosaur, Tenontosaurus tilletti (OMNH 34784) that did not preserve any sign of original biochemistry. Our data indicate that MOR 1125 bone cortices have similar bone elemental distributions to that of an extant bird, which supports preservation of original endogenous chemistry in this specimen