When the barn-owl feasted on bats, an approach to taphonomic analysis

Small vertebrates are a key proxy for paleoenvironmental and paleoclimatic reconstruction, but a previous taphonomic analysis of the paleontological assemblage is needed before facing this kind of approach. Works concerning taphonomy of preyed small vertebrates are abundant in the literature, but chiropters are not usually included as they are only rarely predated. Here we analysed the content of two barn-owl (Tyto alba) pellets that exclusively contained bat remains. Our aim is to assess the effects of digestion inflicted by this predator on certain bat skeletal elements, specifically mandibles and lower teeth. All bat remains were assigned to Pipistrellus sp. They mostly presented slight alteration of the mandible and non-altered enamel, which is an expected result based on previous literature concerning this type of predator. Nevertheless, a few specific specimens showed much more intense alteration. This is most probably due to predator-related factors, although a higher degree of age-related tooth-wear in a specific bat cannot be dismissed.

Distribution and relative abundance of dominant benthic foraminifera and their palaeoecological significance from beach cores sediment in Kerala coast, India

The study on 365 sediment subsamples have been analyzed for benthic foraminifera from beach cores sediment in Kerala coast, India. The recent benthic foraminiferal faunal record that reveals the paleoecological preferences of the different benthic foraminiferal species are reported in this study. A total of 38 species belonging to 22 genera were identified from the study. For benthic foraminiferal faunal study, dry samples were sieved over 125 μm-size sieve and split into suitable aliquots to obtain ~250 specimens of benthic foraminiferal species identified and counted. The recent benthic foraminiferal faunal record assemblages were dominated by species are Ammonia beccarii followed by Ammonia gaimardii, Cancris oblongus, Discopulvinulina bertheloti, Gyroidinoides nitidula, Gyroidinoides cibaoensis and Quinqueloculina seminulum etc. The most dominant genus like Ammonia was recorded in all the samples from the study. Benthic foraminiferal species are utilized for biostratigraphy for several years and have also been confirmed very constructive in paleoceanographic and paleoclimatological modernization. This study, benthic foraminifera the major contributor to the marine biotic community is largely employed as an important tool for paleoclimatic reconstruction for high fossilization potential and a wide range of geographical distribution.

Application of a Diatom Transfer Function to Quantitative Paleoclimatic Reconstruction — A Case Study of Yunlong Lake, Southwest China

Although diatom records from lake sediments have been used for quantitative paleoclimatic reconstruction, their validity and sensitivity have rarely been tested rigorously. At Yunlong Lake, an alpine lake in Southwest China, we studied the seasonal succession of diatom assemblages to produce a mean surface water temperature (MSWT) transfer function. In addition, based on the spatial distribution of surface diatom assemblages with water depth, we produced a diatom-water depth (WD) transfer function. Combined with the analysis of diatom assemblages in a sediment core (YL2013-A), changes in surface water temperature and water level over the last ∼100 years were quantitatively reconstructed using the diatom-based transfer functions. Comparison with records of regional meteorology and reservoir water capacity revealed that the diatom-based lake water level reconstruction is a sensitive indicator of short-term fluctuations in precipitation, and it also reflects a long-term stepwise rise in water level caused by the impounding and large-scale extension of the reservoir. In addition, the diatom-inferred MSWT is consistent with the changes in air temperature prior to large-scale human disturbance of the site. However, after the extension of the reservoir, although the regional air temperature continued to increase, the water temperature decreased substantially. This suggests that the large increase in lake water volume in the short term led to a decrease in the average water temperature, which in turn led to the occurrence of a diatom bloom in the cold season. The results demonstrate that diatom transfer functions based on modern observations of the same lake has a high environmental sensitivity and can be used for the quantitative reconstruction of regional climate change. Overall, our findings provide a foundation for the use of lake diatom records for quantitative paleoclimatic reconstruction on various timescales.

The mutual ecogeographical range and paleoclimatic reconstruction during the Late Pleistocene-Holocene in the Pampas (Argentina) using meso and microvertebrate fossils

The Pampas of Argentina is a large grassland ecosystem located in the oriental region southern of South America. As a study case, we present the results of the paleoclimatic analysis of the Tixi Cave site. This is a paleontological and archeological locality that shows a long chronologic sequence, with radiocarbon dates ranging from the Late Pleistocene to historical times, and one of the best records of meso and microvertebrate fossils in South America. Paleoclimatic reconstruction was assayed using the Mutual Ecogeographic Range method. Ecological niche models were made for each of the living representatives of the fossil taxa reported at the site. Potential distribution areas were superimposed to perform the paleoclimatic inference and to infer the annual average temperature and the annual average precipitation. During the Pleistocene-Holocene transition (12,287 ± 212–11,609 ± 218 ca BP) and in the Middle-Holocene (5592 ± 79 ca BP), colder and drier climates appear in comparison to the present climate, the remaining of the Holocene (3496 ± 81–160 ± 120 ca BP) shows warmer and humid climates as compared to today’s climate conditions. Our results are in agreement with the paleoenvironmental inferences obtained by other proxies, such as deposition, paleosols, phytoliths, diatoms, ostracods, and pollen for Late Pleistocene -Holocene of the region, showing that the abundance of small mammals can accurately record the climatic fluctuations of the Late Pleistocene-Holocene in the Pampas of Argentina.

RECENSIÓN. Advances in Angiosperm Paleobotany and Paleoclimatic Reconstruction – Contributions Honouring David L. Dilcher and Jack A. Wolfe.

La serie Courier Forschungsinstitut Senckenberg (Cfs) publica artículos de interés internacional en el ámbito de la geología y paleontología, con especial énfasis en la publicación de volúmenes especiales que resuman el conocimiento actual sobre alguna de las materias encuadradas en estas temáticas. El volumen 258 incluye parte de los trabajos presentados durante el encuentro de investigadores en Paleobotánica en Gainesville (Florida), auspiciado por el Museo de Historia Natural de Florida. Este volumen se estructura en dos partes bien definidas. La primera incluye las semblanzas personales y académicas de los homenajeados incluyendo un listado de sus publicaciones. La segunda parte recoge 14 contribuciones que abordan los últimos avances en el campo de la Paleobotánica del Cretácico y del Cenozoico y de la Paleoclimatología. Nos encontramos con una obra de gran interés para conocer la trayectoria científica de J. Wolfe y D. Dilcher. Los trabajos publicados en este volumen permiten conocer los avances más significativos alcanzados en los últimos años en el conocimiento del registro fósil de angiospermas y de las interpretaciones climáticas que a partir de estos datos pueden realizarse. Las cuestiones tratadas por los diferentes trabajos de este volumen no abarcan ni mucho menos el total de líneas de investigación que se desarrollan sobre el grupo de las angiospermas. No obstante, este volumen ofrece una magnífica oportunidad para conocer el estado actual de nuestro conocimiento sobre algunos aspectos del último de los grandes planes estructurales de plantas aparecido sobre la tierra.

Paleoclimatic reconstruction in the Tatra Mountains of the western Carpathians during MIS 9–7 inferred from a multiproxy speleothem record

The SC-3 speleothem from Szczelina Chochołowska Cave, located in the Tatra Mountains, was studied in detail. U-series dating and age–depth modeling allowed us to constrain the period of speleothem growth to between approximately 330 and 200 ka, that is, during Marine Isotope Stages (MIS) 9–7. The complementary use of stable isotope analyses, petrographic studies, and trace element analyses allowed the identification of warm and wet climatic conditions that were favorable for speleothem growth during MIS 9e and MIS 9c. Unfavorable climatic periods included the cold glacial conditions of MIS 8 and the MIS 9/MIS 8 transition. The breaks in the growth of the SC-3 stalagmite were most likely connected with a reduction in precipitation in MIS 9a and extreme hydrologic events during MIS 8. Comparisons with other European records suggest that the climatic variability recorded in the speleothem from the Tatra Mountains is not only a record of local environmental conditions but can also be linked to European climatic patterns during both interglacial and glacial intervals. This makes our study the northernmost paleoclimatic record for the whole Carpathian range and one of the very few records from those periods worldwide.