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Vertebral ribs of the anterior thorax in extant birds bear bony prongs called uncinate processes, which improve the mechanical advantage of mm. appendicocostales to move air through the immobile lung and pneumatic air sacs. Among non-avian archosaurs, broad, cartilaginous uncinate processes are present in extant crocodylians, and likely have a ventilatory function. Preserved ossified or calcified uncinate processes are known in several non-avian dinosaurs. However, whether other fossil archosaurs possessed cartilaginous uncinate processes has been unclear. Here, we establish osteological correlates for uncinate attachment to vertebral ribs in extant archosaurs, with which we inferred the presence of uncinate processes in at least 19 fossil archosaur taxa. An ancestral state reconstruction based on the infer distribution suggests that cartilaginous uncinate processes were plesiomorphically present in Dinosauria and arguably in Archosauria, indicating that uncinate processes, and presumably their ventilatory function, have a deep evolutionary history extending back well beyond the origin of birds. A newly discovered osteological correlate for structures associated with ventilatory muscle attachment indicates a deep evolutionary history of respiratory innovation within Archosauria. [ABSTRACT FROM AUTHOR]

The exact provenance of the two associated dodo skeletons collected in the vicinity of Port Louis, Mauritius, around the turn of the 19th century is shrouded in mystery, as well as their collector, the amateur naturalist and barber Louis Etienne Thirioux (1846–1917). The most complete specimen resides in the Mauritius Institute, Port Louis, whereas the second, which is a partial composite, is in the Durban Natural Science Museum (South Africa). Early correspondence between Thirioux and Alfred Newton, Professor of Zoology and Comparative Anatomy at Cambridge University, detailed museum records kept by Ernest Chubb from the Durban Natural Science Museum, and early photographic records of Thirioux's finds shed some light on the early history of the specimens. The Port Louis specimen appears to consist of the bones of a single bird, apart from what appear to be an extra pair of lacrimals, and is essentially complete, including, for instance, the wrist bones, the patella, and the tarsal sesamoid, with the sole exception of the phalanx digiti minoris (present in the Durban specimen). These elements have never been described or illustrated before. The Durban specimen contains elements that most likely derived from a very small number of birds, possibly as few as two. Records indicate that some reconstruction has been undertaken on the Durban specimen, including the discarding of a cervical vertebra. However, regardless of unanswered questions regarding the history and provenance of the Thirioux dodo specimens, they represent the most complete, associated skeletal remains in existence. Citation for this article: Claessens, L. P. A. M., and J. P. Hume. 2015. Provenance and history of the Thirioux dodos; pp. 21–28 in L. P. A. M. Claessens, H. J. M. Meijer, J. P. Hume, and K. F. Rijsdijk (eds.), Anatomy of the Dodo (Raphus cucullatusL., 1758): An Osteological Study of the Thirioux Specimens. Society of Vertebrate Paleontology Memoir 15. Journal of Vertebrate Paleontology 35(6, Supplement). [ABSTRACT FROM AUTHOR]

Despite its status as an icon of extinction and relatively recent disappearance, our knowledge of the anatomy of the dodo has been hampered by a scarcity of preserved remains. The handful of dodo relics that survive from collections made prior to the bird's extinction consist solely of cranial and pedal materials, whereas other dodo skeletons preserved in museum collections are incomplete composites, constructed from subfossil skeletal remains discovered since 1865 at the Mare aux Songes locality. Here we describe the skeletal anatomy of two exceptional dodo specimens, collected around 1904 by amateur naturalist Louis Etienne Thirioux in the caves and crevasses surrounding Le Pouce, which have escaped detailed scientific analysis until now. The Port Louis specimen appears to consist of the skeletal remains of a single bird and is essentially complete, whereas the Durban specimen has been constructed from a limited number of birds but contains many bones that appear to be associated. The Port Louis specimen provides the first information regarding relative skeletal proportions of the dodo. Unique skeletal elements that were unknown or never described scientifically before include the patella, tarsal sesamoids, ulnare and radiale, and distal wing phalanges. The anatomy of the Thirioux dodos supports recent reinterpretations of the dodo as a resilient bird that was well adapted to the Mauritian ecosystem. Citation for this article: Claessens, L. P. A. M., H. J. M. Meijer, and J. P. Hume. 2015. The morphology of the Thirioux dodos; pp. 29–187 in L. P. A. M. Claessens, H. J. M. Meijer, J. P. Hume, and K. F. Rijsdijk (eds.), Anatomy of the Dodo (Raphus cucullatusL., 1758): An Osteological Study of the Thirioux Specimens. Society of Vertebrate Paleontology Memoir 15. Journal of Vertebrate Paleontology 35(6, Supplement). [ABSTRACT FROM AUTHOR]

Pterosaurs, enigmatic extinct Mesozoic reptiles, were the first vertebrates to achieve true flapping flight. Various lines of evidence provide strong support for highly efficient wing design, control, and flight capabilities. However, little is known of the pulmonary system that powered flight in pterosaurs. We investigated the structure and function of the pterosaurian breathing apparatus through a broad scale comparative study of respiratory structure and function in living and extinct archosaurs, using computer-assisted tomographic (CT) scanning of pterosaur and bird skeletal remains, cineradiographic (Xray film) studies of the skeletal breathing pump in extant birds and alligators, and study of skeletal structure in historic fossil specimens. In this report we present various lines of skeletal evidence that indicate that pterosaurs had a highly effective flow-through respiratory system, capable of sustaining powered flight, predating the appearance of an analogous breathing system in birds by approximately seventy million years. Convergent evolution of gigantism in several Cretaceous pterosaur lineages was made possible through body density reduction by expansion of the pulmonary air sac system throughout the trunk and the distal limb girdle skeleton, highlighting the importance of respiratory adaptations in pterosaur evolution, and the dramatic effect of the release of physical constraints on morphological diversification and evolutionary radiation. [ABSTRACT FROM AUTHOR]

Birds are unique among living vertebrates in possessing pneumaticity of the postcranial skeleton, with invasion of bone by the pulmonary air-sac system. The avian respiratory system includes high-compliance air sacs that ventilate a dorsally fixed, non-expanding parabronchial lung. Caudally positioned abdominal and thoracic air sacs are critical components of the avian aspiration pump, facilitating flow-through ventilation of the lung and near-constant airflow during both inspiration and expiration, highlighting a design optimized for efficient gas exchange. Postcranial skeletal pneumaticity has also been reported in numerous extinct archosaurs including non-avian theropod dinosaurs and Archaeopteryx. However, the relationship between osseous pneumaticity and the evolution of the avian respiratory apparatus has long remained ambiguous. Here we report, on the basis of a comparative analysis of region-specific pneumaticity with extant birds, evidence for cervical and abdominal air-sac systems in non-avian theropods, along with thoracic skeletal prerequisites of an avian-style aspiration pump. The early acquisition of this system among theropods is demonstrated by examination of an exceptional new specimen of Majungatholus atopus, documenting these features in a taxon only distantly related to birds. Taken together, these specializations imply the existence of the basic avian pulmonary Bauplan in basal neotheropods, indicating that flow-through ventilation of the lung is not restricted to birds but is probably a general theropod characteristic. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the author's discusses various aspects related to the study of life and history of dodo bird, including its extinction, biomechanics of locomotion, and analysis of its skeleton.

The theropod genus and speciesOrnithomimus veloxwas erected based on a partial hind limb recovered from the late Maastrichtian Denver Formation. A partial manus, which likely belonged to the same individual, was also recovered and described in the same paper.Ornithomimus edmontonicusis the only other valid species currently recognized in the genus. The validity ofOrnithomimus veloxhas been questioned due to its fragmentary nature and because the diagnostic features identified when the species was erected are now considered characteristic for the family. The pes and manus ofOrnithomimus veloxwere never fully prepared. In the original description, reconstructed metatarsals were figured, but manual phalanges, although preserved, were not described. Here we describe and reevaluateOrnithomimus veloxbased upon a new preparation of the specimen. Metacarpal proportions are diagnostic for the genus, with metacarpal I longer than metacarpal II, which in turn is longer than metacarpal III. The pes and manus ofOrnithomimus veloxare smaller than in the type specimen ofOrnithomimus edmontonicus.Ornithomimus veloxcan be distinguished fromOrnithomimus edmontonicusbased on the robusticity of the pes. Material previously referred toOrnithomimus veloxfrom the Kaiparowits Formation of Utah is older and morphologically distinct and does not represent the same species. The morphological disparity and temporal separation observed in specimens referred toOrnithomimus edmontonicussuggest that it may represent a species complex. The redescription and diagnosis ofOrnithomimus veloxprovides a new framework to investigate ornithomimid systematics. Citation for this article: Claessens, L. P. A. M., and M. A. Loewen. 2015. A redescription ofOrnithomimus veloxMarsh, 1890 (Dinosauria, Theropoda). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1034593. [ABSTRACT FROM PUBLISHER]

Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility. [ABSTRACT FROM AUTHOR]