Search results for "Skull"

Erratum to “Identification of unknown dead bodies by X-ray image comparison of the skull using the X-ray simulation program FoXSIS” [Forensic Sci. In…

2001

Quantification de révolution morphologique du crâne des Hominidés et hétérochronies

1998

Abstract Comparisons of adult skulls of various species of great apes, fossil hominids and modern humans in the sagittal, Francfort and ortho-sagittal planes reveal a series of three separate organisation plans: ‘Great Ape’, ‘Australopithecine’ and ‘Homo’, the latter including primitive men ( Homo ergaster-erectus-neandertalensis ) and modern humans ( Homo sapiens ). Morphological changes between these plans are quantified for the first time here by vector fields. This study confirms the existence of cranio-facial contraction, which occurs as a series of leaps. The juvenile morphology of the great ape skull is broadly preserved in adult Homo sapiens, suggesting that numerous heterochronies …

Computed Tomography in Processes at the Base of the Skull and in the Skull Vault

1981

Many CT systems allow detailed examination of the bony structures of the base of the skull and the vault. Elimination of the waterbox and enlargement of the opening of the gantry allows free positioning of the head, use of coronary projections, and studies of the base of the skull. A high-resolution matrix (320 × 320 for the EMI 5005 used in most of the studies in our series) provides a high degree of accuracy. A number of authors has reported on the use of computed tomography in studying the base of the skull, especially for planning surgical proce duresor radiation therapy (Liliequist and Forsell 1976; Bradac et al. 1977 b; Bradac et al. 1977c; Bradac et al. 1978; Hammerschlag et al. 1977…

Skull osteology ofParvilacerta parva, a small-sized lacertid lizard from Asia Minor

2002

The skull of the poorly known Asia Minor lacertid lizard Parvilacerta parva is described. In comparison to other palaearctic lacertids, Parvilacerta parva displays several peculiar traits such as a large braincase, a short parietal table, closed post-temporal openings, reduced ossification, or a large lacrimal. Many features are related to the small size of Parvilacerta parva and are of apparently heterochronic nature, as they can also be found in certain ontogenetic stages of other lacertid species. Small size and heterochrony even seem to be factors involved in the less-developed sexual dimorphism of Parvilacerta parva. The described morphology is interpreted to be related to a life histo…

Paramblypterus duvernoyi(Actinopterygii): skull morphology and intra-specific variation, and its implications for the systematics of paramblypterid f…

1999

ABSTRACT More than 300 specimens of Paramblypterus duvernoyi from four lakes of the Lower Permian of Germany are examined to determine intra-specific variation of this species and to revise the diagnosis of the genus Paramblypterus. For the first time, a three-dimensional model of the skull and the snout of Paramblypterus is reconstructed. A partial tooth bearing premaxilla, which forms the anterior most part of the gape, is described; in contrast, the absence of a premaxilla had until now been considered a synapomorphy of the genus Paramblypterus. Information obtained from the study of P. duvernoyi has required a new revision of Paramblypterus gelberti. A comparison between the two species…

Ornamentation of dermal bones of

2017

Background Amphibians are animals strongly dependent on environmental conditions, like temperature, water accessibility, and the trophic state of the reservoirs. Thus, they can be used in modern palaeoenvironmental analysis, reflecting ecological condition of the biotope. Methods To analyse the observed diversity in the temnospondyl Metoposaurus krasiejowensis from Late Triassic deposits in Krasiejów (Opole Voivodeship, Poland), the characteristics of the ornamentation (such as grooves, ridges, tubercules) of 25 clavicles and 13 skulls were observed on macro- and microscales, including the use of a scanning electron microscope for high magnification. The different ornamentation patterns fou…

Cranial circulation of the pen-tailed tree shrewPtilocercus lowii and relationships of Scandentia

1994

The major cranial arteries and veins are described for a 30-mm crown-rump length fetus of the pen-tailed tree shrewPtilocercus lowii, and comparisons are made with cranial vessels reported in the tree shrewTupaia and with the vascular pattern reconstructed for primitive eutherians.Ptilocercus shares a number of derived features of the cranial circulation withTupaia, which, therefore, represent synapomorphies of tree shrews (Tupaiidae, Scandentia). Included are (1) the enclosure of the intratympanic portion of the internal carotid artery in a bony canal that is floored proximally and distally by the entotympanic and by the petrosal in between, (2) the enclosure of the intratympanic portion o…

Validation procedures in radiological diagnostic models. Neural network and logistic regression

1999

The objective of this paper is to compare the performance of two predictive radiological models, logistic regression (LR) and neural network (NN), with five different resampling methods. One hundred and sixty-seven patients with proven calvarial lesions as the only known disease were enrolled. Clinical and CT data were used for LR and NN models. Both models were developed with cross validation, leave-one-out and three different bootstrap algorithms. The final results of each model were compared with error rate and the area under receiver operating characteristic curves (Az). The neural network obtained statistically higher Az than LR with cross validation. The remaining resampling validatio…

German neuroendoscopy above the skull base

2009

Endoscopy plays an important part in current minimally invasive neurosurgery. The concepts, indications, and standards of current neuroendoscopy were developed in the beginning of the 1990s by several groups of neurosurgeons. Several factors contributed to its success and acceptance, including technical development, influence of other disciplines, and adaptation to neurosurgical requirements. This historical survey focuses on the period when this technique initially emerged, including the scientific discussions of each group as well as the arguments and reasons that led to present intraventricular neuroendoscopy. Interestingly, despite the almost independent development of neuroendoscopic s…

Anatomical Network Analysis of Primate Skull Morphology

2015

Borja Esteve-Altava1,3, Julia Boughner2, Rui Diogo3 and Diego Rasskin-Gutman1. 1Theoretical Biology Research Group, Cavanilles Institute of Biodiversity & Evolutionary Biology, University of Valencia, Valencia, Spain. 2Anatomy & Cell Biology, University of Saskatchewan, Saskatoon, Canada. 3Anatomy, Howard University, Washington, DC USA. boresal@gmail.com, diego.rasskin@uv.es, julia.boughner@gmail.com, rui.diogo@howard.edu