Data from: Bone histological correlates for air sacs and their implications for understanding the origin of the dinosaurian respiratory system

Air sacs are an important component of the avian respiratory system, and corresponding structures also were crucial for the evolution of sauropod dinosaur gigantism. Inferring the presence of air sacs in fossils so far is restricted to bones preserving internal pneumatic cavities and foramina as osteological correlates. We here present bone histological correlates for air-sacs as a new potential identification tool for these elements of the respiratory system. The analysis of several avian and non-avian dinosaur samples revealed delicate fibers in secondary trabecular and secondary endosteal bone that in the former case (birds) is known or in the latter (non-avian dinosaurs) assumed to have been in contact with air sacs, respectively. The bone histology of this “pneumosteal tissue” is markedly different from those regions where muscles attached presenting classical Sharpey’s fibers. The pneumatized bones of several non-dinosaurian taxa do not exhibit the characteristics of this “pneumosteum”. Our new histology-based approach thus can be instrumental in reconstructing the origin of air sacs among dinosaurs and hence for our understanding of this remarkable evolutionary novelty of the respiratory system

Bone histological correlates for air sacs and their implications for understanding the origin of the dinosaurian respiratory system

Air sacs are an important component of the avian respiratory system, and corresponding structures also were crucial for the evolution of sauropod dinosaur gigantism. Inferring the presence of air sacs in fossils so far is restricted to bones preserving internal pneumatic cavities and foramina as osteological correlates. We here present bone histological correlates for air-sacs as a new potential identification tool for these elements of the respiratory system. The analysis of several avian and non-avian dinosaur samples revealed delicate fibers in secondary trabecular and secondary endosteal bone that in the former case (birds) is known or in the latter (non-avian dinosaurs) assumed to have been in contact with air sacs, respectively. The bone histology of this “pneumosteal tissue” is markedly different from those regions where muscles attached presenting classical Sharpey’s fibers. The pneumatized bones of several non-dinosaurian taxa do not exhibit the characteristics of this “pneumosteum”. Our new histology-based approach thus can be instrumental in reconstructing the origin of air sacs among dinosaurs and hence for our understanding of this remarkable evolutionary novelty of the respiratory system

New information on paleopathologies in non-avian theropod dinosaurs: a case study on South American abelisaurids

Abstract Studies on pathological fossil bones have allowed improving the knowledge of physiology and ecology, and consequently the life history of extinct organisms. Among extinct vertebrates, non-avian dinosaurs have drawn attention in terms of pathological evidence, since a wide array of fossilized lesions and diseases were noticed in these ancient organisms. Here, we evaluate the pathological conditions observed in individuals of different brachyrostran (Theropoda, Abelisauridae) taxa, including Aucasaurus garridoi, Elemgasem nubilus, and Quilmesaurus curriei. For this, we use multiple methodological approaches such as histology and computed tomography, in addition to the macroscopic evaluation. The holotype of Aucasaurus shows several pathognomonic traits of a failure of the vertebral segmentation during development, causing the presence of two fused caudal vertebrae. The occurrence of this condition in Aucasaurus is the first case to be documented so far in non-tetanuran theropods. Regarding the holotype of Elemgasem, the histology of two fused vertebrae shows an intervertebral space between the centra, thus the fusion is limited to the distal rim of the articular surfaces. This pathology is here considered as spondyloarthropathy, the first evidence for a non-tetanuran theropod. The microstructural arrangement of the right tibia of Quilmesaurus shows a marked variation in a portion of the outer cortex, probably due to the presence of the radial fibrolamellar bone tissue. Although similar bone tissue is present in other extinct vertebrates and the cause of its formation is still debated, it could be a response to some kind of pathology. Among non-avian theropods, traumatic injuries are better represented than other maladies (e.g., infection, congenital or metabolic diseases, etc.). These pathologies are recovered mainly among large-sized theropods such as Abelisauridae, Allosauridae, Carcharodontosauridae, and Tyrannosauridae, and distributed principally among axial elements. Statistical tests on the distribution of injuries in these theropod clades show a strong association between taxa-pathologies, body regions-pathologies, and taxa-body regions, suggesting different life styles and behaviours may underlie the frequency of different injuries among theropod taxa

The Venice specimen of Ouranosaurus nigeriensis (Dinosauria, Ornithopoda)

Ouranosaurus nigeriensis is an iconic African dinosaur taxon that has been described on the basis of two nearly complete skeletons from the Lower Cretaceous Gadoufaoua locality of the Ténéré desert in Niger. The entire holotype and a few bones attributed to the paratype formed the basis of the original description by Taquet (1976). A mounted skeleton that appears to correspond to O. nigeriensis has been on public display since 1975, exhibited at the Natural History Museum of Venice. It was never explicitly reported whether the Venice specimen represents a paratype and therefore, the second nearly complete skeleton reported in literature or a third unreported skeleton. The purpose of this paper is to disentangle the complex history of the various skeletal remains that have been attributed to Ouranosaurus nigeriensis (aided by an unpublished field map of the paratype) and to describe in detail the osteology of the Venice skeleton. The latter includes the paratype material (found in 1970 and collected in 1972), with the exception of the left femur, the right coracoid and one manus ungual phalanx I, which were replaced with plaster copies, and (possibly) other manus phalanges. Some other elements (e.g., the first two chevrons, the right femur, the right tibia, two dorsal vertebrae and some pelvic bones) were likely added from other individual/s. The vertebral column of the paratype was articulated and provides a better reference for the vertebral count of this taxon than the holotype. Several anatomical differences are observed between the holotype and the Venice specimen. Most of them can be ascribed to intraspecific variability (individual or ontogenetic), but some are probably caused by mistakes in the preparation or assemblage of the skeletal elements in both specimens. The body length of the Venice skeleton is about 90% the linear size of the holotype. Osteohistological analysis (the first for this taxon) of some long bones, a rib and a dorsal neural spine reveals that the Venice specimen is a sub-adult; this conclusion is supported by somatic evidence of immaturity. The dorsal ‘sail’ formed by the elongated neural spines of the dorsal, sacral and proximal caudal vertebrae characterizes this taxon among ornithopods; a display role is considered to be the most probable function for this bizarre structure. Compared to the mid-1970s, new information from the Venice specimen and many iguanodontian taxa known today allowed for an improved diagnosis of O. nigeriensis

The Venice specimen of Ouranosaurus nigeriensis (Dinosauria, Ornithopoda)

Ouranosaurus nigeriensis is an iconic African dinosaur taxon that has been described on the basis of two nearly complete skeletons from the Lower Cretaceous Gadoufaoua locality of the Ténéré desert in Niger. The entire holotype and a few bones attributed to the paratype formed the basis of the original description by Taquet (1976). A mounted skeleton that appears to correspond to O. nigeriensis has been on public display since 1975, exhibited at the Natural History Museum of Venice. It was never explicitly reported whether the Venice specimen represents a paratype and therefore, the second nearly complete skeleton reported in literature or a third unreported skeleton. The purpose of this paper is to disentangle the complex history of the various skeletal remains that have been attributed to Ouranosaurus nigeriensis (aided by an unpublished field map of the paratype) and to describe in detail the osteology of the Venice skeleton. The latter includes the paratype material (found in 1970 and collected in 1972), with the exception of the left femur, the right coracoid and one manus ungual phalanx I, which were replaced with plaster copies, and (possibly) other manus phalanges. Some other elements (e.g., the first two chevrons, the right femur, the right tibia, two dorsal vertebrae and some pelvic bones) were likely added from other individual/s. The vertebral column of the paratype was articulated and provides a better reference for the vertebral count of this taxon than the holotype. Several anatomical differences are observed between the holotype and the Venice specimen. Most of them can be ascribed to intraspecific variability (individual or ontogenetic), but some are probably caused by mistakes in the preparation or assemblage of the skeletal elements in both specimens. The body length of the Venice skeleton is about 90% the linear size of the holotype. Osteohistological analysis (the first for this taxon) of some long bones, a rib and a dorsal neural spine reveals that the Venice specimen is a sub-adult; this conclusion is supported by somatic evidence of immaturity. The dorsal 'sail' formed by the elongated neural spines of the dorsal, sacral and proximal caudal vertebrae characterizes this taxon among ornithopods; a display role is considered to be the most probable function for this bizarre structure. Compared to the mid-1970s, new information from the Venice specimen and many iguanodontian taxa known today allowed for an improved diagnosis of O. nigeriensis

LambertzEtAl_BiolLett_Bone-Histological-Correlates-AirSacs_ESM2

Interactive three-dimensional model of the Europasaurus holgeri vertebral neural arch

Dataset from thesis entitled "Disease in the Cretaceous: A comparative study of Iguanodon and hadrosaur palaeopathology"

The following dataset represents the list of material and supplementary analyses for the thesis entitled “Disease in the Cretaceous - A Comparative Study of Iguanodon and Hadrosaur Palaeopathology”, reporting all the specimens from the visited museum collections and those published in the literature. Appendix 1 is a list of all the palaeopathological specimens known from the ornithopod literature, subdivided in 11 body parts. Appendices 2 to 4 represent the complete list of studied material, added to the literature revision, that describes each pathological element in the three morphotypes (corresponding to basal (e.g. Dryosaurus), “intermediate” (e.g. Iguanodon) and derived ornithopods e.g. (Edmontosaurus)). The specimens are subdivided into 16 body parts, as their identification was done personally, helping to discern between, for example, middle to distal caudals. Graphical representations are proposed at the end of each appendix. In Appendix 5, specimens belonging to Morphotype C from four museum collections are compared to each other, treated as different “populations”, with graphical distributions and codification for the linear regression, the latter done in the software SPSS. Appendix 6 is a complete schematical description of all caudal vertebrae from Morphotype C, reporting measurements and type of injuries/deformations. Although the studied specimens are listed in Appendix 2 to 4, their osteology is extensively described in Appendix 7, grouped per body regions between the three morphotypes. Some of the most peculiar and/or uncertain specimens were scanned via a microCT device, and their descriptions are reported in Appendix 8. A wide number of caudal neural spines from Appendix 4 are extensively described in Appendix 9 and listed in tables together with the angulation of the bending of the pathological spines. The final Appendix 10 corresponds to the published article about the palaeopathologies detected in the holotype of Parasaurolophus walkeri during the collection visit at the Royal Ontario Museum (Canada). The palaeopathological analysis provided an unexpected reevaluation of the neck musculature of the species. Included below is a list of the current filenames of the dataset and the corresponding thesis chapter in which they first appeared with original short file name: Appendix1: List of the published palaeopathological specimens in ornithopoda = Appendix1_Chapter2_Published_pathologies Appendix 2: List of palaeopathological specimens recognised in basal ornithopods (e.g. Dryosaurus) = Appendix2_Chapter3_MorphotypeA Appendix 3: List of palaeopathological specimens recognised in “intermediate” ornithopods (e.g. Iguanodon) = Appendix3_Chapter3_MorphotypeB Appendix 4: List of palaeopathological specimens recognised in derived ornithopods (e.g. Edmontosaurus) = Appendix4_Chapter3_MorphotypeC Appendix 5: Statistical overview and analysis of four museum collections of hadrosaurid specimens = Appendix5_Chapter3_Analysis Appendix 6: Schematical description of hadrosaurid caudal vertebrae = Appendix6_Chapter3_CaudalVertebrae Appendix 7: Osteological and pathological description of the palaeopathological specimens from the three morphotypes = Appendix7_Chapter3_DescriptionPathologicalBones Appendix 8: Internal anatomy of hadrosaurid pathological bones using microtomographic scanning = Appendix8_Chapter3_CTscans Appendix 9: Isolated caudal neural spines: Osteological description, pathologies and measurements = Appendix9_Chapter5_DescriptionMatingInjuries Appendix 10: Publication about the palaeopathological description of the injuries in the holotype of Parasaurolophus walkeri = Appendix10_Bertozzo et al 2020 The current dataset files are embargoed until 31 Dec 2026

New paleobiological perspectives on Iguanodon from the digitalization of the historical collection in Belgium

In 1878, more than thirty, almost complete, skeletons of Iguanodon were found in a mine in Bernissart (Belgium). Together with the English taxa studied by Owen and Leidy’s Hadrosaurus from the US – all based on more or less complete specimens – the Bernissart iguanodons shed a unique opportunity to realize what dinosaur really looked like in the early years of paleontology. Since then, these specimens are exhibited in the Royal Belgian Institute of Natural Sciences in Brussels. The Bernissart iguanodontians are thought to represent at least four different populations, and this offers a unique possibility to analyze intraspecific variations, behavioral interactions, paleopathology, and biomechanics. However, these materials suffer from severe pyrite decay, strongly limiting their accessibility for science and outreach. Here, we present the latest developments of the Belspo BRAIN-be 2.0 digitization project that aims to create a digital archive of the Bernissart individuals, currently encompassing two species, Iguanodon bernissartensis and Mantellisaurus atherfieldensis. Given the shiny and reflecting surface of the bones (provoked by the restoration resins and pyritization), we focused our methodology on structured-light surface scanners. The holotype of I. bernissartensis, the paratype of M. atherfieldensis, and at least ten other skeletons are now fully digitized in 3D and assembled in their most updated anatomical stance. The project shows that most of the individuals of I. bernissartensis possess similar body sizes, with greater variation of size and shape in the limbs. Some of the pathologies have been evaluated via tomography, whereas the skull of M. atherfieldensis was analyzed via microCT, showing discrepancies with the original osteological description. Future developments of the project will cover further paleobiological aspects of the behavior of Early Cretaceous iguanodontians, such as the use of the spike-like pollex and the range of motions of tails and limbs