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Tooth counts through growth in diapsid reptiles: implications for interpreting individual and size-related variation in the fossil record.

Tooth counts are commonly recorded in fossil diapsid reptiles and have been used for taxonomic and phylogenetic purposes under the assumptio … d in extant squamates (lizards and snakes) but is poorly understood in archosaurs (crocodylians and dinosaurs). Here, we document tooth count variation in two species of extant crocodylians (Alligator mississippiensis and Crocodylus porosus) as well as a large varanid lizard (Varanus komodoensis). We test the hypothesis that variation in tooth count is driv …

Acoustic communication in crocodilians: from behaviour to brain.

Crocodilians and birds are the modern representatives of Phylum Archosauria. Although there have been recent advances in our understanding of the phylogeny and ecology of ancient archosaurs like dinosaurs, it still remains a challenge to obtain reliable information about their behaviour. The comparative study of birds and crocodiles represents one approach to this interesting problem. One of their shared behavioural features is the use of acoustic communication, especially in the context of parental care. Although considerable data are available for birds, information concerning crocodilians i…

Organizational principles of integumentary organs: Maximizing variations for effective adaptation.

The integument serves as the interface between an organism and its environment. It primarily comprises ectoderm-derived epithelium and mesen … olution, enabling animals to explore new ecological niches, as seen in the emergence of feathers on dinosaurs. These principles demonstrate how multi-scale organ adaption in the amniotes can maximize diverse and flexible integumentary organ phenotypes, producing a vast repertoire for natural selection and thereby providing effective adaptation and evolution …

The neuroanatomy of Zulmasuchus querejazus (Crocodylomorpha, Sebecidae) and its implications for the paleoecology of sebecosuchians.

The endocranial structures of the sebecid crocodylomorph Zulmasuchus querejazus (MHNC 6672) from the Lower Paleocene of Bolivia are described in this article. Using computed tomography scanning, the cranial endocast, associated nerves and arteries, endosseous labyrinths, and cranial pneumatization are reconstructed and compared with those of extant and fossil crocodylomorphs, representative of different ecomorphological adaptations. Z. querejazus exhibits an unusual flexure of the brain, pericerebral spines, semicircular canals with a narrow diameter, as well as enlarged pharyngotympanic sinus

Long Gu (Os Draconis): Textual research, modern scientific evaluation, and quality control challenges.

ETHNOPHARMACOLOGICAL RELEVANCE: Long Gu (Os Draconis), a mineral medicine with over 2000 years of use in traditional Chinese medicine, is facing a critical juncture. Its identity has been clarified scientifically-from a mythologized "dragon bone" to a fossilized mammalian bioapatite-yet its sustainable clinical application is threatened by resource depletion, widespread domestic and international adulteration, and the lack of modern quality standards. AIM OF THE STUDY: This review aims to systematically analyze the evolution of Long Gu through historical materia medica, define its authentic c

Biomechanical modeling and sensitivity analysis of bipedal running ability. I. Extant taxa.

I used a simple mathematical model of the inverse dynamics of locomotion to estimate the minimum muscle masses required to maintain quasi-st … g approach should be reliable for reconstructing running ability in extinct bipeds such as nonavian dinosaurs. The models also elucidated how key features are important for bipedal running capacity, such as limb orientation, muscle moment arms, muscle fascicle lengths, and body size. None of the animals modeled had extensor muscle masses acting about any on …

Synchrotron imaging of dentition provides insights into the biology of Hesperornis and Ichthyornis, the "last" toothed birds.

BACKGROUND: The dentitions of extinct organisms can provide pivotal information regarding their phylogenetic position, as well as paleobiolo … amel. The extension rate of Hesperornis tooth dentine appears relatively high compared to non-avian dinosaurs. Root attachment is found for the first time to be fully thecodont via gomphosis in both taxa, but in Hesperornis secondary evolution led to teeth implantation in a groove, at least locally without a periodontal ligament. Dental replacement is shown …

A bacterial artificial chromosome library for the Australian saltwater crocodile (Crocodylus porosus) and its utilization in gene isolation and genome characterization.

BACKGROUND: Crocodilians (Order Crocodylia) are an ancient vertebrate group of tremendous ecological, social, and evolutionary importance. They are the only extant reptilian members of Archosauria, a monophyletic group that also includes birds, dinosaurs, and pterosaurs. Consequently, crocodilian genomes represent a gateway through which the molecular evolution of avian lineages can be explored. To facilitate comparative genomics within Crocodylia and between crocodilians and other archosaurs, we have constructed a bacterial artificial chromosome (BAC) library for the Australian saltwater croc…

Preparation and In Vitro Evaluation of Ibuprofen Spherical Agglomerates.

Important transformations of the pectoral girdle are related to the appearance of flight capabilities in the Dinosauria. Previous studies on this topic focused mainly on paravians yet recent data suggests flight evolved in dinosaurs several times, including at least once among non-avialan paravians. Thus, to fully explore the evolution of flight-related avian shoulder girdle characteristics, it is necessary to compare morphology more broadly. Here, we present information from pennaraptoran specimens preserving pectoral girdle elements, including all purportedly volant taxa, and extensively com…

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 nea

[Time trend in mesothelioma and lung cancer risk in asbestos workers in Italy].

Diplodocids are among the best known sauropod dinosaurs. Numerous specimens of currently 15 accepted species belonging to ten genera have been reported from the Late Jurassic to Early Cretaceous of North and South America, Europe, and Africa. The highest diversity is known from the Upper Jurassic Morrison Formation of the western United States: a recent review recognized 12 valid, named species, and possibly three additional, yet unnamed ones. One of these is herein described in detail and referred to the genus Galeamopus. The holotype specimen of Galeamopus pabsti sp. nov., SMA 0011, is repre…

Reduced T-cell receptor CD3zeta-chain protein and sustained CD3epsilon expression at the site of mycobacterial infection.

Sigilmassasaurus brevicollis is an enigmatic theropod dinosaur from the early Late Cretaceous (Cenomanian) of Morocco, originally based on a few isolated cervical vertebrae. Ever since its original description, both its taxonomic validity and systematic affinities were contentious. Originally considered to represent its own family, Sigilmassasauridae, the genus has variously been suggested to represent a carcharodontosaurid, an ornithischian, and, more recently, a spinosaurid. Here we describe new remains referrable to this taxon and re-evaluate its taxonomic status and systematic affinities.

"Different is nice, but it sure isn't easy": differentiating the spectrum of autism from the spectrum of normalcy.

Brian is a 15-year-old boy who has been just changed to your practice because of a change in insurance plans. When taking the social history … ; for example, he is very interested in knowing all about the dynasties in China. His interests are dinosaurs and anime. He is described as "An all-or-nothing type kid" when it comes to his interests. If his father tries to explain to Brian why he would like something done in a particular way, Brian will explode, and at times, he has even tried to shove his …

A review of the osteoderms of lizards (Reptilia: Squamata).

Osteoderms are mineralised structures consisting mainly of calcium phosphate and collagen. They form directly within the skin, with or without physical contact with the skeleton. Osteoderms, in some form, may be primitive for tetrapods as a whole, and are found in representatives of most major living lineages including turtles, crocodilians, lizards, armadillos, and some frogs, as well as extinct taxa ranging from early tetrapods to dinosaurs. However, their distribution in time and space raises questions about their evolution and homology in individual groups. Among lizards and their relative…

Pathogenesis and management of alcoholic hepatitis.

Brachiosauridae is a clade of titanosauriform sauropod dinosaurs that includes the well-known Late Jurassic taxa Brachiosaurus and Giraffatitan. However, there is disagreement over the brachiosaurid affinities of most other taxa, and little consensus regarding the clade's composition or inter-relationships. An unnamed partial sauropod skeleton was collected from middle-late Oxfordian (early Late Jurassic) deposits in Damparis, in the Jura department of eastern France, in 1934. Since its brief description in 1943, this specimen has been informally known in the literature as the 'Damparis saurop…

Contributions of paleorheumatology to understanding contemporary disease.

As paleopathology has evolved from observational speculation to analysis of testable hypotheses, so too has recognition of its contribution to vertebrate paleontology. In the presence of significant structural and density variation (between matrix and osseous structures), x-rays provide an additional perspective of osseous response to stress and disease. As film techniques are time and cost expensive, fluoroscopy has proven a valuable alternative. Radiologic techniques also allow non-invasive "sectioning" of specimens, illustrating significant internal detail. The object can be "split" on a pl

Regulation of bone-renal mineral and energy metabolism: the PHEX, FGF23, DMP1, MEPE ASARM pathway.

More than 300 million years ago, vertebrates emerged from the vast oceans to conquer gravity and the dry land. With this transition, new adaptations occurred that included ingenious changes in reproduction, waste secretion, and bone physiology. One new innovation, the egg shell, contained an ancestral protein (ovocleidin-116) that likely first appeared with the dinosaurs and was preserved through the theropod lineage in modern birds and reptiles. Ovocleidin-116 is an avian homolog of matrix extracellular phosphoglycoprotein (MEPE) and belongs to a group of proteins called short integrin-bindin…

Killing me softly--future challenges in apoptosis research.

The induction of apoptosis, a highly regulated and clearly defined mode of cell dying, is a vital tenet of modern cancer therapy. In this review we focus on three aspects of apoptosis research which we believe are the most crucial and most exciting areas currently investigated and that will need to be better understood in order to enhance the efficacy of therapeutic measures. First, we discuss which target to select for cancer therapy and argue that not the cancer cell as such, but its interaction with the microenvironment is a more promising and genetically stable site of attack. Second, the

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… Basically the dynamic mechanisms at play that led to the extinction of the dinosaurs and the rise of our mammalian ancestors (who were competing for similar ecological niches) are the same that lead to the emergence of a treatment-resistant tumor after massive apoptosis induction ( Figure 4 ). … ) competing for a single ecological niche (Earth) upon a drastic change in the environment (a comet hitting the planet) is the extinction of the dinosaurs and rise of the mammals during Cretaceous-Paleogene extinction event (better known as K-T extinction). …

Evolution of Cancer Pharmacological Treatments at the Turn of the Third Millennium.

The medical history of cancer began millennia ago. Historical findings of patients with cancer date back to ancient Egyptian and Greek civilizations, where this disease was predominantly treated with radical surgery and cautery that were often ineffective, leading to the death of patients. Over the centuries, important discoveries allowed to identify the biological and pathological features of tumors, without however contributing to the development of effective therapeutic approaches until the end of the 1800s, when the discovery of X-rays and their use for the treatment of tumors provided the

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… In fact, in some fossil remains of dinosaurs or prehistoric animals traces of bone tumors have been found, probably osteosarcomas or bone metastases (Rothschild et al., 2003 ; Dumbravbrevea et al., 2016 ). …