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.     

Extinction pattern of marine Ostracoda across the Pliensbachian-Toarcian boundary in the Cordillera Ibérica, NE Spain: Causes and consequences

This paper discusses the extinction pattern of the Pliensbachian-Toarcian boundary (PTB) ostracod assemblages at the Almonacid de la Cuba section (Cordillera Ibérica, NE Spain), which has been recently proposed as auxiliary boundary stratotype for the PTB. The ostracod record shows that the main Early Jurassic ostracod extinction event occurred not at the end of the Pliensbachian, but near the top of the Mirabile ammonite Subzone, Tenuicostatum ammonite Zone (Early Toarcian). On the basis of the evaluation of PTB ostracod record, a new causal explanation for the Early Toarcian ostracod turnover is proposed. This paper suggests that a reorganization of surface and deep-water circulations caused by the opening of the Hispanic Corridor could have generated a mild cooling episode, finally affecting the survival of healdioid ostracods.     

Elemental Content in Brown Rice by Inductively Coupled Plasma Atomic Emission Spectroscopy Reveals the Evolution of Asian Cultivated Rice

The phylogenetic relationship for classification traits and eight mineral elements in brown rice (Oryza sativa L.) from Yunnan Province in China was carried out using microwave assisted digestion followed by inductively coupled plasma atomic emission spectroscopy, and the analytical procedures were carefully controlled and validated. In general, the results show that the mean levels of K, Ca, Mg, Fe and Cu in brown rice for 789 accessions of rice landraces was distinctly lower than that of improved cultivars. They further demonstrate that Ca plays an important role in the differentiation of subspecies indica-japonica, especially to enhance adaptation of cold stress, and that five mineral elements in brown rice enhance the eurytopicity from landrace to improved cultivar. Hierarchical cluster analysis, using average linkage from SPSS software based on eight mineral elements in brown rice, showed that Yunnan rice could be grouped into rice landrace and improved cultivar, with the rice landrace being further clustered into five subgroups, and that, interestingly, purple rice does not cluster with either of the groups. Our present data confirm that indica is the closest relative of late rice and white rice, and that they constitute rice landraces together, whereas japonica is the closest relatives of non-nuda, early-mid and glutinous rice. It is further shown that japonica, non-nuda, early-mid, glutinous, white and red rice might be more primitive than indica, nuda, late, non-glutinous and purple rice, respectively.     

Numerical analyses of distributions of Iberian and Balearic endemic monocotyledons

Chorological information concerning 182 taxa of monocotyledons endemic to the Iberian Peninsula and Balearic Islands was compiled and related to the 100×100 km, 50×50 km and 10×10 km UTM grids. Distributions were analysed using multivariate methods (two-way indicator species analysis and detrended correspondence analysis) for each scale. Comparison of results allows recognition of several floristic elements and sectors (i.e. Balearic, Murcian-Almerian, south western) common to all three scales, whereas other regions are assigned to different sectors depending on the grid size considered. As a consequence of the increase in detail, characteristics such as number of sectors, the outline of boundaries and continuity or fragmentation of the areas also change. These factors are discussed.     

Malacofauna continental holocena y paleoambientes en Villa Valle María (Diamante, Entre Ríos, Argentina)

The molluscan fauna recovered from Holocene continental sediments at Villa Valle María fossiliferous locality (Diamante, Entre Ríos, Argentina), eolian in origin and dated at 2,490 ± 45 ¹⁴C yrs. B.P. on Bulimulus sp, is reported. It represents the first illustrated record of Quaternary molluscs from loess sequences in Argentina. It is represented exclusively by land snails which belong to five gastropod families (Pupillidae, Succineidae, Ferussaciidae, Orthalicidae and Scolodontidae), 7 genera and 9 species: Gastrocopta nodosaria (d’Orbigny), Succinea meridionalis d’Orbigny, Cecilioides consobrina (d’Orbigny), Bulimulus apodemetes (d’Orbigny), B. bonariensis bonariensis (Rafinesque), Bulimulus sp, Naesiotus pollonerae (Ancey), N. deletangi (Parodiz), Miradiscops brasiliensis (Thiele) and Scolodonta semperi (Doering). The first record of Miradiscops is reported for Entre Ríos province. The gastropod assemblage, typical of habitats with plant cover and leaves and trunks as substrate, is similar to the modern molluscan fauna found today along southern Entre Ríos province (Mesopotamian District in the Subtropical Dominium), an area characterized by a warm-temperate steppe continental scenario. However, the associated record of S. meridionalis, typical of environments with higher humidity contents like ponds, suggests local more humid temporary environmental conditions such as palustrine habitats during the time span considered. Our results provide additional evidence regarding the occurrence of a dominant eolian event which produced the reworking and subsequent accumulation of superficial deflated sediments on the Pampean region. They add to previous models considering a dry period between 3,500 and 1,400 yrs. B.P. over the central Argentine plains.     

Improved cryopreservation protocol for Blanca-Celtibérica buck semen collected by electroejaculation

The collection of sperm samples by electroejaculation (EE) leads to an increase of the production of seminal plasma which could modify the tolerance of spermatozoa to the cryopreservation procedure. This study aims to compare a standard sperm cryopreservation protocol for samples collected by artificial vagina (AV) with the same protocol and modifications to this for samples obtained by EE. Semen from six males of Blanca-Celtibérica goat breed was collected by AV (control) and EE, and three experiments were conducted. In Experiment 1, it was examined the effects of egg yolk concentration contained in freezing extender (0%, 1.5%, 10% and 20% of egg yolk); in Experiment 2, it was evaluated the cooling rate from 30 to 5 °C (fast: 10 min and slow: 90 min) and the temperature of glycerol addition (30 and 5 °C); and in Experiment 3, it was examined the time of equilibration at 5 °C (0, 1, 2 or 3 h). A heterologous in vitro fertilization test was carried out in order to compare the fertility of control samples with that resulting from the EE protocol which showed the highest sperm quality. Results showed greater sperm motility parameters after thawing for control samples cryopreserved in standard conditions in the three experiments. For samples collected by EE, extender with 20% egg yolk, a slow cooling rate and a longer equilibration time (3 h) provided higher sperm quality, and no differences were observed between temperatures of glycerol addition. Samples collected by EE and cryopreserved with the protocol which yielded the best sperm quality after thawing showed higher fertility compared to AV.     

Contrasting patterns of vertical stratification in two moth families in a Costa Rican lowland rain forest

The vertical stratification of two species-rich moth families (Lepidoptera: Arctiidae, Geometridae) was analysed in a lowland rain forest in Costa Rica. Moths were trapped with automatic 8 W ultraviolet light traps at three sites in the understorey and canopy of a primary forest at the La Selva Biological Station (10.4° N, 84.0° W). A total of 846 arctiid moths (148 species) and 946 geometrid moths (140 species) were analysed. Species richness and diversity of arctiid moths was significantly lower in the understorey than in the canopy (Fisher's alpha: 24 vs. 49) whereas geometrid moths showed an inverse pattern (Fisher's alpha: 44 vs. 27). This resulted in an overall increase in the proportion of conspicuously coloured species towards the canopy. Moth ensembles were clearly separated in multidimensional scaling ordinations, and differed significantly in their faunal composition and dominance between the strata. The available host plant data suggest that the flight height of moths was determined by larval resource availability. Examples include understorey flyers such as the geometrid genus Eois feeding on Piper, and canopy flyers such as the arctiid moth genera Aclytia, Macrocneme and Poliopastea which feed on lianas.