Los pumas (Puma concolor) como agentes tafonómicos. Análisis actualístico de un sitio de matanza en los Andes de Mendoza, Argentina

A taphonomic study of the carcass of an adult guanaco (Lama guanicoe) recently killed and consumed by one or more pumas (Puma concolor) in the Laguna del Diamante reserve (Mendoza province, Argentina) is exposed, and the case is discussed in the light of the available taphonomic information on this agent in America. The carcass was dispersed along more than 30 m and basically devoid of soft tissues. Thirty-four percent of the bones presented tooth modifications, removal of bone tissue and edge damage, mostly attributable to pumas. Some of these modifications are considerable, as in the case of the skull. The results of the study suggest that bone modifications are intense as compared to other taphonomic studies on this felid. The implications of this are discussed, and the conclusion is reached that more knowledge is needed on the range of variation in puma taphonomic action and the conditions under which such variation occurs.     

Tafonomía y contexto paleoambiental de los restos de un cetáceo del Mioceno medio de Tarragona (NE España)

A new finding of a marine mammal is documented from the middle Miocene of El Camp basin in Tarragona (NE Spain). The incomplete and disarticulated bone remains belong to the skeleton of a juvenile cetacean. These remains appear deposited above a transgression surface and included within a glauconitic calcisiltite layer. This unit constitutes the beginning of a shallowing-upwards sequence and was deposited under low-energy conditions and low sedimentation rates in a middle-outer platform setting. This context was responsible for the long exposure of the remains and, consequently, an extension of the biostratinomic stage. These conditions favored the natural decomposition and disarticulation of the carcass, allowing the action of different types of scavenging organisms. The interpretation of the paleoenvironmental setting is based in the combination of different datasets: taphonomic data of the bone remains, paleoecologic and taphonomic information provided by the fauna associated to the bones, and ichnologic and sedimentologic interpretation of the sediments where the fossils are included. Combination of such different proxies enables a very good characterization of the paleoenvironmental context of the studied fossils.     

Estructuras de escape y equilibrio asociadas a Conichnus conicus como indicadores de tasas de sedimentación variables en medios litorales tortonienses del SO de España

Numerous and large vertically extensive specimens of Conichnus conicus are described from the Tortonian deposits of the central Guadalquivir Basin (SW Spain). These burrowing structures form a low bioturbation index of the ichnofabric, which allows one to infer the original depositional setting. Both ichnological and sedimentological features suggest a coastal to shallow marine environment dominated by high sediment supply and high-energy sedimentary processes. Conichnus exhibits a characteristic internal fabric that reflects changes in sedimentation rates linked to various processes: (1) initial substrate penetration by the tracemaker; (2) gradual retrusive movement in response to rapid but continuous sediment aggradation; 3) moderate to high rates of retrusive migration as a consequence of rapid to very rapid sediment aggradation and tracemaker escape; and, finally, (4) abandonment of the burrow or burial of the tracemaker subsequently in response to extremely high sediment accumulation rates. Conichnus has been also described from other areas with similar deposits of different ages, where its important value as a paleoenvironmental indicator similarly has been indicated.     

La acción tafonómica de mamíferos carnívoros en el sitio arqueológico Inca Cueva-cueva 4, borde oriental de la Puna argentina

In this paper, a model of carnivore taphonomic action in the Argentinean Puna is applied to archaeological site Inca Cueva-cueva 4, on the Eastern Fringe of the Puna East of the Andes cordillera, which contains hunter-gatherer occupations dating to the early and middle Holocene. Different indicators, such as the low levels of bone modifications (ca. 2 to 8% NISP), consisting mainly in subtle marks, suggest a low intensity of the intervention of carnivores during the formation of these deposits. Variables such as the frequency of carnivore scats attest to repeated carnivore visits to the cave, but the “dilution effect” upon the small faunal assemblages these carnivores tend to accumulate in a context of larger zooarchaeological assemblages would have faded their traces away.     

Filicales y Bennettitales del Cretácico Inferior de Carazuelo, provincia de Soria, España

Silicified woods of the fern Tempskya riojana Barale and Viera and the Bennettitales Cycadeoidea barbarae Crisafulli nov. sp., found together with undetermined conifer woods, from the NW of Carazuelo, province Soria, are described. This site is located south of the so-called San Saturio fault which runs parallel to Road N-234. The fossil trunks are included in the “Conglomerados poligénicos, areniscas y arcillas” fluviatile sediments, dated as Paleogene. The original source of these fossils could be Tera and/or Oncala Groups, both Early Cretaceous in age and outcropping close by at Fuentetecha, Fuensaúco and North of Soria. Similar plant fossil findings from this region are reported and some mistakes in the geological mapping are analyzed. The Tempskya specimens were histologically poorly preserved, but had enough anatomical characters to be undoubtedly assigned to Tempskya riojana. The new species Cycadeoidea barbarae is described, with fairly well preserved cellular structure, viz., pith, vascular cylinder, cortex, foliar/branch traces, as well as strobili surrounded by foliar scales and apical seminal cones. An important and new aspect of the new species is that it includes morphologically and anatomically preserved both fructifications and vegetative parts, whereas these are usually find separated by other species of Bennettitales.     

Taphonomy and taphofacies models of the Pliocene deposits of Vejer de la Frontera (Cádiz, SW Spain)

A quantitative taphonomic analysis of the fossil assemblages, together with a sedimentary study of the Pliocene deposits of the Vejer Basin (Cádiz, Spain), has been carried out. This multidisciplinary analysis has allowed us to establish with great precision the palaeoenvironmental conditions under which these materials were formed. The Pliocene deposits can be divided into three units, named from bottom to top: Unit 1, Unit 2 and Unit 3. Unit 1 is formed of medium-to-coarse-grained sands at the base, corresponding to subtidal bar deposits. At the top, the sands become coarser, and beach and littoral dunes were formed. Within these sedimentological contexts, the fossil remains exhibit a strong degree of taphonomic destruction due to high hydrodynamic energy. Unit 2, consisting of clays, corresponds to deposits formed in a protected coastal bay. A low-energy environment allowed the fossils to maintain a good state of conservation and even thin-shelled bivalves with a delicate ornamentation are preserved. Unit 3 comprises highly bioclastic sands and calcarenites-calcirudites. This unit displays a shallowing upwards trend, passing from deposits generated under shallow subtidal conditions in the lower part to materials deposited on beaches and coastal dunes in the upper part. Under these conditions, the fossil remains show a high degree of taphonomic destruction. In Units 1 and 3, the fossils are mainly accumulated in horizontal beds, with extensive lateral continuity and with erosive bottoms and graded tops. These accumulations of fossils are interpreted as tempestites. As compared with the fossils preserved in surrounding sediments, the taphonomic attributes of these bioclasts suggest a superposition of the background and event processes. During normal conditions, the high energy of the littoral environments produced a strong degree of taphonomic destruction. During storm events, a mixture of taphonomic attributes was produced: high fragmentation and disarticulation and little abrasion and edge rounding of the fragments. This mixture was a consequence of sudden burial after storms, which prevented long periods of exposure of the bioclasts in the taphonomically active zone. Three taphofacies models are proposed, based on taphonomic attributes of fossils contained in the different units: inner-shelf taphofacies, protected shallow-lagoon taphofacies and storm bed taphofacies.     

Informe: análisis de las publicaciones de socios de la Sociedad Española de Geriatría y Gerontología del año 2006 al 2011

Data is presented from the survey conducted by the Sociedad Española de Geriatría y Gerontología (SEGG) (Spanish Society of Geriatrics and Gerontology) among its members in order to assess their scientific production between 2006 and 2011, specifically articles in journals that are indexed in the Science Citation Index. The scientific quality of the publications was quantified using the number of times every article was cited and the journal's impact factor. A total of 162 out of the 2450 members responded (6.6%), reporting a total of 903 individual articles, 335 (37%) of them in geriatrics-specific journals, and 568 (63%) in other journals of other specialties. The number of publications increased yearly from 128 in 2006 to 201 in 2010. The scientific quality could be calculated for 530 articles. On average, publications have been cited 8.2 times (median: 2), with the range of citations being from 0 to 242. The average impact factor was 3.1 (median 2.4), ranging from 0 to 53.5. A number of articles have been published in some of the largest impact factor journals, in those of general-interest, as well as geriatrics-specific and basic science journals.     

Proposition d’un référentiel taphonomique fossile de faunes issues d’avens-pièges

Pitfalls are formations characterized by a vertical opening that connects the karstic system to the outside. The presence of faunas trapped without the intervention of man or carnivores, offers the opportunity to establish a fossil referential of modifications generated by identified taphonomic agents. Three natural deposits containing large faunal accumulations feed this work. Their characteristics differ. The Igue des Rameaux, to Saint-Antonin-Noble-Val in Tarn-et-Garonne, is a pitfall which contains two accumulations of fauna independent from the Middle Pleistocene. Scavenging by man and carnivores (hyenas and wolves) are observed. The Igue du Gral, to Sauliac-sur-Célé in Lot, is a second pitfall. His principal phase of filling took place 14,000 years ago. Man did not exploit this assemblage. The activity of wolves is locally important, some animals are scavenged. The Grotte de l’Escale, in Bouches-du-Rhône, contains a very important filling of lower and middle Pleistocene. For the levels presented here, only a very weak presence of carnivores is attested. The thar (Hemitragus bonali) is the majority specie. We describe here the main forms of climato-edaphic modifications: fragmentation, dissolution, weathering and deposits observed on the osseous material. A differential analysis enables us to evaluate the variability of the situations according to the stratigraphic units and the different species. In a second time, we estimate the impact of the taphonomic agents on the differential conservation of bones and skeletal representations. Many phenomena are producing a significant correlation between anatomical representations and osseous densities. However, we find for all the species a certain homogeneity in the skeletal profiles where no precise element dominates. In a last part, we give two examples of the use of the taphonomic phenomena in the individualization of filling episodes within sometimes disrupted stratigraphies.     

Microstratigraphy and taphonomy of rudist shell concentrations in Upper Cretaceous limestones,Cilento area (central-southern Italy)

Rudist bed type and distribution has been investigated in Upper Cretaceous limestones cropping out in the northern Cilento area (southern Italy). These limestones are dominated by fine-grained, peloidal, silty packstone in which rudist-rich beds are intercalated. An inner shelf environment may be inferred on the basis of the recognized sedimentary and taphonomic features. The rudist shell beds are characterized by low species diversity, with slight differences in abundance of a few species belonging to the Durania, Bournonia, Sauvagesia, Gorjanovicia and Biradiolites genera, which usually form oligo- or monospecific congregations. The internal fabric of these levels (i.e. orientation, arrangement, packing and sorting of the skeletal elements; internal microstratigraphy) has permitted us to distinguish two broad shell bed categories: (a) shell beds considered as “Primary Shell Concentration”, in which the shell concentration is essentially created by the behaviour of local shell producers, preserved in situ and in growth position; (b) shell beds considered as “Hydraulic Shell Concentration”, which were deposited under the influence of hydraulic processes and/or input of surrounding bioclastic sediments. The taphonomic analyses allowed us to highlight the role of some of the biotic and abiotic factors that controlled the distribution of the rudists in the various habitats. The increase of physical disturbance (especially hydrodynamism) is the primary difference between these shell bed categories. The establishment and development of the densest rudist congregations appear to be related to the accommodation space made available by means of relative sea level rise. The lowering of the sea level was often accompanied by the increased influence of waves and/or currents on the seabed and the consequent sediment disturbance and demise of the rudist lithosome, although other factors cannot be excluded.     

Relación entre el rendimiento en la prueba de estación unipodal y la velocidad del centro de presión en adultos mayores

Introduction

Frequent falls are one of the most important health problems in the elderly population. The unipedal stance test (UPST), asses postural stability and is used in fall risk measures. Despite this, there is little information about its relationship with posturographic parameters (PP) that characterizes postural stability. Center of pressure velocity (CoPV) is one of the best PP that describes postural stability. The aim of this study was to analyze the relation between UST score and CoPV in elderly population.

Materials and methods

A sample of 38 healthy elderly subjects where divided in two groups according to their UPST score, low performance (LP, n = 11) and high performance (HP, n = 27). The correlation between UPST score and COP mean velocity (CoPmV), recorded from a posturographic test, was analyzed between both groups.

Results

An inverse correlation between UPST score and CoPmV was found in both groups. However, this was higher in the LP group (r = −0.69, P = .02) compared to the HP (r = −0.39, P = .04).

Conclusions

Based on the results of this investigation, it may be concluded that the achievement on UPST has an inverse relationship with CoPmV, especially in subjects with low performance in the UPST.     

Implantación de una Unidad de Ortogeriatría de Agudos en un hospital de segundo nivel

Background

Patients with hip fracture (HF), due to their characteristics, require a specific support. The Acute Orthogeriatric Unit (OGU) has been shown to be one of the most beneficial.

Objective

To evaluate the main variables of HF patients treated at an OGU and compare them with the previous referral model (RC).

Material and methods

A prospective observational study with retrospective control was conducted on 169 patients, split into two groups. In the RC group, patients were admitted to conventional trauma ward. In the OGU group, an early geriatric assessment was performed, and patients were simultaneously attended daily by the orthopaedic surgeon, nurse and geriatrician, and the surgery times, work load, discharge and destination, were planned in a weekly meeting with the rest of professionals.

Results

A total of 71 patients were included in the RC group and 96 in the OGU group. The preoperative characteristics were similar, except for a slightly higher comorbidity in the OGU group. The OGU patients were operated on earlier (3.82±2.08 vs 4.61±2.5 days; P<.32), and overall hospital stay was reduced by 28% (11.84±4.04 vs 16.46±8.4 days; P<.001). The functional efficiency (Barthel Index at discharge-Barthel Index at admission/overall stay - stay before surgery) was higher in the OGU group (1.56±0.7 vs 2.61±1.1; P<.05). There were no differences in functional status, mortality or discharge location.

Conclusions

The OGU is a level of care that provides effective medical care in HF patients in general hospitals.     

Foraminiferal taphofacies in the Mississippian rocks of the Guadiato area, SW Spain

Summary Microfacies analysis of over 1800 standard thin-sections of upper Viséan and Pendleian-aged platform limestones from southwestern Spain (Guadiato area) shows that foraminiferal assemblages contain many allochthonous specimens. The analysis of the cementation, recrystallization, abrasion, bioerosion, encrustation, dissolution, taphonomic distortion, orientation and sorting allow the recognition of eight taphofacies. They are based on the taphonomic features observed within the foraminiferal assemblages, which reflect the environmental conditions in which foraminifera were sedimented as well as about early diagenesis. The environmental conditions may be ascertained from the analysis of the biostratinomic processes, which comprise the energy, waves, tides, redox conditions, etc. The mechanisms of taphonomic alteration may be quantified, and thus the appearance or absence of these alterations may be used to define taphofacies of shallow- and deep-water environments, such as those from tidal flat, shoal, outer platform, microbial mound or slope. Moreover, the relationship among these taphofacies also helps to define depositional mechanisms and products, such as debris flows or olistolites.     

Study of the cuspal ridges of the upper first molars in a modern Japanese population

Materials used were dental casts of the upper first molars of modern Japanese subjects, comprising 29 males and 25 females. Their molar occlusal surfaces were photographed by moiré contourography using the standard trigonal plane. The ridges of a cusp, comprising a central ridge and mesial and distal accessory ridges, were identified from the patterns of the moiré fringes. The central ridge was observed in all cusps except for the hypocone in both sexes. Frequencies of the mesial and distal accessory ridges of trigonal cusps were over 90% except for the distal accessory ridge of the metacone, and those of the hypocone were under 25% in both sexes. These values were generally higher in males than in females, especially for the distal accessory ridge of the metacone. The running pattern of the cuspal ridges showed little difference between sexes. The oblique ridge which was higher than the central groove formed a saddle-like structure. This ridge was observed in all materials, but its heights and structural components varied remarkably. In this study, the distal accessory ridge of the metacone was found to be incorporated into the oblique ridge in about 13% of cases. Variability in the running pattern of the ridges within a single cusp was highest in the hypocone and lowest in both the paracone and protocone. The results obtained are considered to represent the stability or reductive tendency of cusps in the upper first molars.     

Asociación entre la realización de ejercicio e indicadores de funcionamiento físico y cognitivo. Comparativa de resultados en función de la edad

Background

Gerontology research shows the importance of physical exercise for active aging. This study demonstrates the relationship between the practice of aerobic exercise, and physical fitness (muscle strength, respiratory capacity and motor speed) and cognitive performance (memory and visual-perceptual speed) and analyzes whether age is a modulating factor of this relationship.

Material and methods

The sample included 690 subjects with an age range of 30-85 years. The level of physical exercise was assessed using self-report form. Two sub-scales were used for the evaluation of cognitive performance: Digit Span Backwards and Digit Symbol (both are sub-scales of the Wechsler Adult Intelligence Scale - WAIS). The physical fitness was assessed using bio-behavioral measurements (strength, lung capacity, speed). To test the combined effect of exercise and age on the two variables (physical fitness and cognitive performance) two separate factorial analysis of variance were performed (procedure - general linear model: Univariate).

Result

The most significant result showed that scores on cognitive performance is a function of the intensity of the physical activity (F=4.8; P<0.002). With regard to physical fitness, its relationship with physical exercise is also significant (F=4.10; P<0.007) as well as the interaction between exercise and age (F=2.2; P<0.001).

Conclusions

The intensity in achieving aerobic exercise is associated with physical fitness and cognitive performance. Age has a specific weight in the association between exercise and physical fitness, this effect is higher in the older age groups (65-74 and 75-85 years for 30-49 and 50-64 years). These data suggest the compensatory effect of exercise on decline in old age.     

Experimental manipulation leading to induction of dorsal ectodermal ridges on normal limb buds results in a phenocopy of the eudiplopodia chick mutant

Elongation of chick limb buds depends on the presence of the apical ectodermal ridge which is induced by subjacent limb bud mesoderm. Recombination experiments have shown that the limb bud mesoderm loses the capacity to induce ridges by late stage 17. Moreover, in normal limb development only one ridge forms. However, in the eudiplopodia chick mutant accessory ectodermal ridges form on the dorsal surface of limb buds as late as stage 22. Tissue recombinant experiments show that the mutation affects the ectoderm, extending the time it responds to ridge induction (Fraser and Abbott, 1971a, Fraser and Abbott, 1971b while the mesoderm is normal. The result is polydactyly, with extra digits dorsal to the normal digits. Because eudiplopodia limb bud dorsal mesoderm can induce ridges at stage 22 but is unaffected by the gene, genetically normal dorsal limb bud mesoderm may also be able to induce ridges after stage 17. To test this possibility we grafted stages 14–18 flank ectoderm to normal limb bud dorsal mesoderm and found that mesoderm from stages 17 through 20 was able to induce a ridge and subsequently dorsal digits developed. Limbs with duplicate digits were similar to eudiplopodia limbs. In other experiments, stage 18, 19, and 20 leg bud dorsal ectoderm did not form ridges when grafted to leg bud dorsal mesoderm of the same stage, indicating a lack of response to the mesoderm. Finally, the inductive capacity of limb bud mesoderm appeared to be reduced compared to mesoderm at pre-limb bud stages. These experiments demonstrate a spatially generalized potential in limb bud dorsal mesoderm to induce ridges during the stages when the apical ridge is induced. The determination of where the ridge will form and the acquired inability of limb bud dorsal ectoderm to respond to induction by underlying mesoderm are necessary early pattern forming events which assure that a single proximodistal limb axis will form.     

Upper Pliocene bivalve shell concentrations from the Lower Chelif basin (NW Algeria): Systematics,sedimentologic and taphonomic framework

Sedimentologic and palaeontological investigation of the Upper Pliocene Slama Formation in the Lower Chelif Basin (NW Algeria) led us to collect important bivalve assemblages for taxonomic and taphonomic purposes. A rather comprehensive inventory list of Upper Pliocene bivalves from northwestern Algeria is now available and consists of 30 species, 17 of which are extinct ones. Four principal taphonomic attributes were analysed: bioerosion, encrustation, fragmentation, and abrasion. Physical and biogenic sedimentary structures are used for palaeoenvironmental interpretations. The taphonomic, sedimentologic and ichnological characteristics of most of the deposits suggests they originated from discontinuous processes of winnowing and bypassing of sediments, probably due to the action of storms in shallow waters, mainly in the shoreface depositional environment. The bivalve assemblage is dominated by disarticulated valves and displays significant taphonomic alteration in the shells. Sclerobionts traces in shells particulary affect the oyster shells. Bioerosion traces are predominately those of clionid sponges (Entobia isp.), polychaetes (Maeandropolydora isp. and Caulostrepsis isp.), bivalves (Gastrochaenolites isp.), and of predatory gastropods (Oichnus isp.). Among the sclerobionts, the identified encrusters were juvenile oyster recruits, barnacles, polychaetes (serpulid tubeworms), bryozoans (Microporella sp. and Acanthodesia sp.), and vermetid gastropods (Petaloconchus intortus).     

Caracterización microfaunística de una transgresión marina : Formación Agrio (Cretácico inferior), Cuenca Neuquina, Argentina

Distinctive sedimentological and micropalaeontological responses characterise the basal interval of the Agrio Formation (Valanginian) in central-western Argentina, which is associated to a transgressive event. The effect of the sea-level rise is interpreted from the record of abundant radiolarians and the widespread marlstone and limestone deposits associated with eutrophication of surface waters and development of low-oxygen conditions on the sea-floor. Such a situation accords with pyrite and organic matter rich laminated sediments, as well as with a monotypic foraminiferal assemblage of Epistomina. Bi/plano-convex trochospiral test, epifaunal/semi-epifaunal microhabitat, and deposit-feeding trophic strategy are favourable features for adaptation of this genus to oxygen depressed sea-bottom conditions. The large size of the test could be related to chemolithotrophic bacterial symbionts. Epistomina loncochensis nov. sp. BALLENT is described.     

Osteoderm microstructure of “rauisuchian” archosaurs from South America

In this contribution we analyze and discuss the microanatomy and histology of postcranial osteoderms of a number of “rauisuchians” from different localities of South America (Argentina and Brazil). The studied sample includes osteoderms of Fasolasuchus tenax, Prestosuchus chiniquensis, Saurosuchus galilei and an undetermined rauisuchian from Brazil. The bone microanatomy of the osteoderms is variable: whereas some specimens have a rather compact structure, others show a diploe architecture with a central cancellous core bordered by two compact cortices. Both external and basal cortices are mainly composed of poorly vascularized, fine and coarse parallel-fibred bone and networks of interwoven and mineralized fiber bundles. The internal region of the non-remodeled specimens consists of a well-vascularized core in which the intrinsic fibers exhibit important variations (even in the same specimen), ranging from coarse, parallel-fibred to woven-fibred bone tissues. Lines of arrested growth (LAGs) are well recorded in both basal and external cortices. Differences in the bone microstructure (compact vs. diploe) could be related to the age, sex and reproductive status of the sampled individuals. Hence, age estimation based on the count of LAGs in rauisuchian osteoderms appears to be reliable only in the early stages of ontogeny. The bone microstructure suggests that rauisuchian osteoderms were originated through a mechanism that involves both intramembranous and metaplastic ossifications.