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Author(s): Patrick M. O'Connor (corresponding author) [1]; Leon P. A. M. Claessens [2] Birds are unique among living vertebrates in possessing pneumaticity of the postcranial skeleton, with invasion of bone [...]

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]

The article presents data from the cineradiographic investigation of the in vivo visceral and skeletal kinematics of lung ventilation in two palaeognaths, the emu, Dromaius novaehollandiae and the Chilean tinamou, Nothoprocta perdicaria, and the neognathous helmeted guinea fowl, Numida meleagris. The study found out that the sternal movement is elliptical rather than linear and scissor-like. The distal ends of the sternal ribs moved dorsally, rather than ventrally, upon inspiration in conjunction to its outward-forward displacement. Moreover, the angular changes at the coracosternal joint can enhance sternal movement, while furcular bending might be an auxiliary mechanism by which the clavicular air sac is compressed and expanded.

The article offers information on the cineradiographic study of lung ventilation in American alligator, Alligator mississippiensis. The result of the study showed that A. mississippiensis' breathing pattern is diphasic and intermittent. In addition, it was observed that excited or agitated animals may exhibit triphasic breathing pattern. It was also noticed that before a dive, there is a partial expiration at the end of a series of breaths. Moreover, the diaphragmatic aspiration pump appears to be able to generate a large tidal volume at relatively low metabolic cost. Meanwhile , the osteological correlates of the crocodilian aspiration pump identified in the study provided a framework for interpretation of respiratory kinematics in extinct archosaurs and other groups.

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]

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.

An introduction to the journal is presented in which the editor discusses an article on the relationship between locomotion and ventilation in turtles, the detailed analysis on American alligators, alligator mississippiensis, thoracoabdominal skeletal structure to examine the kinematics of lung ventilation, and the analysis avian ventilatory mechanics.

Why aggressive traits evolve in some species but not in others is poorly understood. We modeled the population dynamics of the extinct Mauritius dodo and Rodrigues solitaire to examine divergent pathways in the evolution of aggression. Whereas the dodo conformed to island syndrome predictions of tameness, its sister-taxon the solitaire evolved strong sexual dimorphism and aggressive traits. We computed rates of change in island size from sea level modeling and connected island size change to population dynamics by integrating a Hawk-Dove game theory model for territory competition with a population model. We find that the rapid rate of decrease in island size likely was an important trigger for the onset of aggressive behavior and that aggressive behavior becomes fixed if a tipping point is reached where island size falls below a critical threshold., Competing Interests: Authors declare that they have no competing interests., (© 2024 The Author(s).)

Unlike most tetrapods, in extant crocodylians the acetabulum is formed by only two of the three skeletal elements that constitute the pelvis, the ilium, and ischium. This peculiar arrangement is further confused by various observations that suggest the crocodylian pelvis initially develops from four skeletal elements: the ilium, ischium, pubis, and a novel element, the prepubis. According to one popular historical hypothesis, in crocodylians (and many extinct archosaurs), the pubis fuses with the ischium during skeletogenesis, leaving the prepubis as a distinct element, albeit one which is excluded from the acetabulum. Whereas the notion of a distinct prepubic element was once a topic of considerable interest, it has never been properly resolved. Here, we combine data gleaned from a developmental series of Alligator mississippiensis embryos, with a revised interpretation of fossil evidence from numerous outgroups to Crocodylia. We demonstrate that the modern crocodylian pelvis is composed of only three elements: the ilium, ischium, and pubis. The reported fourth pelvic element is an unossified portion of the ischium. Interpretations of pelvic skeletal homology have featured prominently in sauropsid systematics, and the unambiguous identification of the crocodylian pubis provides an important contribution to address larger scale evolutionary questions associated with locomotion and respiration., (Copyright © 2012 Wiley Periodicals, Inc.)

Birds and crocodylians, the only living archosaurs, are generally believed to employ pelvic girdle movements as a component of their respiratory mechanism. This in turn provides a phylogenetic basis for inferring that extinct archosaurs, including dinosaurs, also used pelvic girdle breathing. I examined lung ventilation through cineradiography (high-speed X-ray filming) and observed that alligators indeed rotate the pubis to increase tidal volume, but did not observe pelvic girdle movement contributing to lung ventilation in guinea fowl, emus or tinamous, despite extensive soft-tissue motion. Re-examination of fossil archosaurs reveals that pubic rotation evolved in basal crocodyliforms and that pelvic girdle breathing is not a general archosaurian mechanism. The appearance of pelvic aspiration in crocodyliforms is a striking example of the ability of amniotes to increase gas exchange or circumvent constraints on respiration through the evolution of novel accessory breathing mechanisms., (Copyright 2004 The Royal Society)