Search results for "Carnivora"
showing 10 items of 26 documents
On the phylogeny and zoogeography of the leptarctines (Carnivora, Mammalia)
1982
A restudy of the skull and mandible ofLeptarctus neimenguensis Zhai from the Middle Miocene of China and the preparation of its auditory region led to the recognition of new features. The most important among them is the presence of a small suprameatal fossa partly hidden in the bony mastoid process corresponding to the structure described inPlesiogale andParagale (Schmidt-Kittler 1981) and representing the most primitive type of the mustelid middle ear.
Influence of ventral tegmental area (A10 region) on flight behaviour elicited by hypothalamic stimulation in the cat.
1993
The influence of the ventral tegmental area (VTA) (dopaminergic A10 group neurons) on flight behaviour, induced by hypothalamic stimulation, was studied in the cat. Co-stimulation of hypothalamus and VTA (ipsi- or contralateral) induced an increase of the flight latency. Slow-motion analysis of flight behaviour showed that this increase was due to the augmentation of the fixation latency (FL) whereas the upright latency (UL) was not modified. Sulpiride injection (50 mg/kg i.p.) provoked the disappearance of VTA effect without affecting the basal behavioural sequence. The results show that DA A10 group neurons increase the attentive component of the flight reaction, suggesting a possible inf…
Self-organized dynamics in spatially structured populations
2001
Self-organization and pattern formation represent the emergence of order in temporal and spatial processes. Self-organization in population ecology is gaining attention due to the recent advances concerning temporal fluctuations in the population size of dispersal-linked subunits. We shall report that spatially structured models of population renewal promote the emergence of a complex power law order in spatial population dynamics. We analyse a variety of population models showing that self-organization can be identified as a temporal match in population dynamics among local units, and how the synchrony changes in time. Our theoretical results are concordant with analyses of population data…
Musteloidea (Carnivora, Mammalia) del Mioceno Superior de Venta del Moro (Valencia, España)
2011
The purpose of the present work is to describe the Musteloidea from the Late Miocene locality of Venta del Moro (Valencia, Spain). We have identified the following species: Martes ginsburgi nov. sp., Lutra affinis Gervais, 1859, Plesiogulo monspessulanus Viret, 1939 and Promephitis alexejewi Schlosser, 1924. Besides Plesiogulo monspessulanus which was already described in this locality and in Las Casiones (MN 13, Teruel Basin), we are approaching an unedited Musteloidea assemblage from the Miocene of the Iberian Peninsula. The m1 of Martes ginsburgi nov. sp. is similar in size and morphology to the Asian species of the genus, M. anderssoni and M. zdanskyi, but it differs in having a very wi…
Presencia de Vulpes praeglacialis (Kormos, 1932) en el yacimiento pleistoceno de la Sierra de Quibas (Abanilla, Murcia)
2006
We describe the first remains of Canidae from the Lower Pleistocene karstic locality of Quibas (Abanillas, Murcia) that increasing the representation of carnivores in this site. These fossils are identified as Vulpes praeglacialis, the typical Lower Pleistocene fox. This assignment is based on their small size and the poorly developed posterior cuspid of the p/3.
Do More Highly Organized Collagen Fibrils Increase Bone Mechanical Strength in Loss of Mineral Density After One-Year Running Training?
1999
The aim of this study was to evaluate the effects of long-term running training on the structural properties of bone. Ten beagle dogs ran according to a strenuous progressive program (up to 40 km/day) for 1 year. At the end of the training program, there was a significant reduction in bone mineral density (up to 9.7%) in the vertebrae of the runner dogs as compared with 10 sedentary control dogs. Polarized light microscopy of the vertebral trabecular bone, however, displayed proportionally higher retardation values of the collagen network of the runner dogs than of the sedentary dogs, suggesting a reorganization in a more parallel manner in the collagen fibrils. The concentration and cross-…
Kretzoiarctos gen. nov., the oldest member of the giant panda clade
2012
The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8–7 mya) was recognized as the oldest undoubted me…
Assessing host-parasite specificity through coprological analysis: a case study with species of Corynosoma (Acanthocephala: Polymorphidae) from marin…
2011
In this paper we report an investigation of the utility of coprological analysis as an alternative technique to study parasite specificity whenever host sampling is problematic; acanthocephalans from marine mammals were used as a model. A total of 252 scats from the South American sea lion, Otaria flavescens, and rectal faeces from 43 franciscanas, Pontoporia blainvillei, from Buenos Aires Province, were examined for acanthocephalans. Specimens of two species, i.e. Corynosoma australe and C. cetaceum, were collected from both host species. In sea lions, 78 out of 145 (37.9%) females of C. australe were gravid and the sex ratio was strongly female-biased. However, none of the 168 females of …
Correlation of carnassial tooth size and body weight in recent carnivores (mammalia)
1988
The correlation between the lower carnassial crown area and the body weight is examined for modern carnivores. It is very high, but the ursids and felids show a relationship different from the other carnivore families. Some exceptions are discussed. The possibility of predicting body weight for fossils is given.
Tissue elastance and fluid conduction in normotensive and hypertensive intracerebral mass haematomas.
1988
This is an investigation into the prognostic factors of 117 patients with spontaneous normo- and hypertensive intracerebral haematomas, supported by animal experiments. Preserved tissue elastance and fluid conduction enables the drainage of intrinsic haematoma serum into the CSF spaces in normotensive patients, who showed an increased extension of a perifocal hypodensity in the CT. Arterial hypertension decreased the possibility of fluid resolution. Our experimental studies showed that in hypertensive cases the serum remained trapped in the haematoma, which explains the small hypodense area around the haematoma in most of the hypertensive cases. If as an exception in hypertensives of perifo…