Understanding the Impact of Trampling on Rodent Bones

Experiments based on the premise of uniformitarism are an effective tool to establish patterns of taphonomic processes acting either before, or after, burial. One process that has been extensively investigated experimentally is the impact of trampling to large mammal bones. Since trampling marks caused by sedimentary friction strongly mimic cut marks made by humans using stone tools during butchery, distinguishing the origin of such modifications is especially relevant to the study of human evolution. In contrast, damage resulting from trampling on small mammal fossil bones has received less attention, despite the fact that it may solve interesting problems relating to site formation processes. While it has been observed that the impact of compression depends on the type of substrate and dryness of the skeletal elements, the fragility of small mammal bones may imply that they will break as a response to compression. Here, we have undertaken a controlled experiment using material resistance compression equipment to simulate a preliminary experiment, previously devised by one of us, on human trampling of owl pellets. Our results demonstrate that different patterns of breakage can be distinguished under wet and dry conditions in mandibles, skulls and long bones that deform or break in a consistent way. Further, small compact bones almost always remain intact, resisting breakage under compression. The pattern obtained here was applied to a Pleistocene small mammal fossil assemblage from Wonderwerk Cave (South Africa). This collection showed unusually extensive breakage and skeletal element representation that could not be entirely explained by excavation procedures or digestion by the predator. We propose that trampling was a significant factor in small mammal bone destruction at Wonderwerk Cave, partly the product of trampling caused by the raptor that introduced the microfauna into the cave, as well as by hominins and other terrestrial animals that entered the cave and trampled pellets covering the cave floor

Systemic Type I IFN Inflammation in Human ISG15 Deficiency Leads to Necrotizing Skin Lesions

Most monogenic disorders have a primary clinical presentation. Inherited ISG15 deficiency, however, has manifested with two distinct presentations to date: susceptibility to mycobacterial disease and intracranial calcifications from hypomorphic interferon-II (IFN-II) production and excessive IFN-I response, respectively. Accordingly, these patients were managed for their infectious and neurologic complications. Herein, we describe five new patients with six novel ISG15 mutations presenting with skin lesions who were managed for dermatologic disease. Cellularly, we denote striking specificity to the IFN-I response, which was previously assumed to be universal. In peripheral blood, myeloid cells display the most robust IFN-I signatures. In the affected skin, IFN-I signaling is observed in the keratinocytes of the epidermis, endothelia, and the monocytes and macrophages of the dermis. These findings define the specific cells causing circulating and dermatologic inflammation and expand the clinical spectrum of ISG15 deficiency to dermatologic presentations as a third phenotype co-dominant to the infectious and neurologic manifestations.Fil: Martin Fernandez, Marta. Icahn School Of Medicine At Mount Sinai; Estados Unidos. King Saud University; Arabia SauditaFil: Bravo García Morato, María. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Gruber, Conor. Icahn School Of Medicine At Mount Sinai; Estados Unidos. King Saud University; Arabia SauditaFil: Murias Loza, Sara. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Malik, Muhammad Nasir Hayat. Twincore; Alemania. University Of Lahore; Países Bajos. Leibniz Universitat Hannover; Alemania. Helmholtz Gemeinschaft; AlemaniaFil: Alsohime, Fahad. King Saud University; Arabia SauditaFil: Alakeel, Abdullah. King Saud University; Arabia SauditaFil: Valdez, Rita. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Doctor Cosme Argerich; ArgentinaFil: Buta, Sofija. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Buda, Guadalupe. Bitgenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Biología Celular e Histología; ArgentinaFil: Marti, Marcelo Adrian. Bitgenia; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Biología Celular e Histología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Larralde, Margarita. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Boisson, Bertrand. L'institut Des Maladies Génétiques Imagine; Francia. The Rockefeller University; Estados Unidos. Universite de Paris; FranciaFil: Feito Rodriguez, Marta. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Qiu, Xueer. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Chrabieh, Maya. L'institut Des Maladies Génétiques Imagine; FranciaFil: Al Ayed, Mohammed. Najran University; Arabia SauditaFil: Al Muhsen, Saleh. King Saud University; Arabia SauditaFil: Desai, Jigar V.. National Institutes of Health; Estados UnidosFil: Ferre, Elise M.N.. National Institutes of Health; Estados UnidosFil: Rosenzweig, Sergio D.. National Institutes of Health; Estados UnidosFil: Amador-Borrero, Blanca. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Bravo-Gallego, Luz Yadira. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Olmer, Ruth. Hannover Medical School; Alemania. German Center for Lung Research; AlemaniaFil: Merkert, Sylvia. Hannover Medical School; Alemania. German Center for Lung Research; AlemaniaFil: Bret, Montserrat. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Sood, Amika K.. University of North Carolina; Estados UnidosFil: Al-rabiaah, Abdulkarim. King Saud University; Arabia SauditaFil: Temsah, Mohamad Hani. King Saud University; Arabia SauditaFil: Halwani, Rabih. University of Sharjah; Emiratos Arabes UnidosFil: Hernandez, Michelle Marilyn. University of North Carolina; Estados UnidosFil: Pessler, Frank. Twincore; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Casanova, Jean Laurent. The Rockefeller University; Estados Unidos. Necker Hospital for Sick Children; Francia. Howard Hughes Medical Institute; Estados Unidos. Universite de Paris; FranciaFil: Bustamante, Jacinta. The Rockefeller University; Estados Unidos. Necker Hospital for Sick Children; Francia. Universite de Paris; FranciaFil: Lionakis, Michail S.. National Institutes of Health; Estados UnidosFil: Bogunovic, Dusan. Icahn School Of Medicine At Mount Sinai; Estados Unido

Geodivulgar: Geología y Sociedad

Con el lema “Geología para todos” el proyecto Geodivulgar: Geología y Sociedad apuesta por la divulgación de la Geología a todo tipo de público, incidiendo en la importancia de realizar simultáneamente una acción de integración social entre estudiantes y profesores de centros universitarios, de enseñanza infantil, primaria, de educación especial y un acercamiento con público con diversidad funcional

Small mammal Taphonomy, Palaeoecology and compared variability of climatic phenomena between the Northern and the Southern Hemisphere during the Holocene

El Holoceno se caracteriza por la presencia de pulsos climáticos rápidos, cuyo impacto en ecosistemas terrestres es poco conocido. En este sentido, los micromamíferos son considerados buenos indicadores terrestres de cambio ambiental, cuya presencia en los yacimientos fósiles depende en gran medida de la depredación. Por tanto, los estudios tafonómicos son una herramienta fundamental para confirmar la información ambiental extraída de los micromamíferos. Esta tesis plantea una comparación de las fluctuaciones climáticas del Holoceno entre ambos hemisferios y su impacto en ecosistemas terrestres, haciendo hincapié en la importancia de aplicar estudios tafonómicos para la obtención de interpretaciones paleoecológicas.La tesis es un compendio de cinco publicaciones. El primer trabajo presentado proporciona diferentes criterios para distinguir la digestión y la abrasión por agua y sedimento en elementos esqueléticos poscraneales. La distinción de ambos procesos es fundamental para una correcta interpretación del depredador involucrado y para descartar eventos de transporte que pueden llegar a comprometer la integridad de las inferencias paleoecológicas.Los tres trabajos posteriores se centran en el estudio de asociaciones fósiles de micromamíferos de Argentina de dos áreas ecotonales: la región Pampeana y la provincia de Mendoza. Para la región Pampeana, los ambientes de preservación, así como los distintos agentes de producción involucrados en estas asociaciones (entre los que destaca la intervención humana) demostraron estar influenciando las interpretaciones paleoecológicas. Aún así, fue posible inferir una importante estabilidad ambiental a lo largo del Holoceno para esta región. Este estudio también puso de manifiesto la necesidad de evaluar la utilidad paleoclimática del roedor Pseudoryzomys simplex. Para ello, se aplicaron análisis de nicho climático que demostraron que los procesos de antropización han reducido severamente el área de distribución actual de esta especie, poniendo en duda su utilidad como indicador de condiciones más tropicales en la región Pampeana. Por último, los análisis tafonómicos y paleoecológicos de Cueva Salamanca (sur de la provincia de Mendoza) reforzaron los resultados previos de estudios publicados para esta área en los que se observaron bajas o nulas fluctuaciones en los hábitats.Los resultados obtenidos para la Península Ibérica fueron englobados en una última publicación y en la discusión general de la tesis. Se planteó el estudio tafonómico de el yacimiento de El Mirador (Burgos, España). Este yacimiento registra una fase árida asociada al impacto del Evento Bond de hace 4200 años a través del registro polínico. Sin embargo, el análisis tafonómico puso de manifiesto la influencia de las preferencias del depredador sobre el conjunto taxonómico de micromamíferos analizados. A pesar de que el impacto de este evento no es claramente observado sobre la microfauna, los procesos tafonómicos posdeposicionales corroboraron la fase árida indicada por el polen. En contraste, los resultados paleoecológicos de otros sitios Holocenos de la Península, parecen indicar un cambio en la composición del paisaje durante este evento y fluctuaciones de hábitat más aparentes a lo largo de este periodo, especialmente en el Norte y Noreste de la Península Ibérica. Sin embargo, no todos los yacimientos de la Península han sido tafonómicamente estudiados.Los trabajos presentados en esta tesis respaldan la importancia de los análisis tafonómicos en las inferencias paleoambientales. La aplicación de estudios tafonómicos y paleoecológicos en periodos más antiguos como el Pleistoceno medio y final, proporcionará más información para corroborar las diferencias observadas a través de los resultados paleoecológicos obtenidos para Argentina y la Península Ibérica.Peer reviewe

When the opportunist becomes specialist: Comparison of the small mammal diet of eagle owl and barn owl in southwest Spain

Small vertebrate assemblages are usually the result of predator accumulations. Predatory activity and predator preferences may have an influence in the general view of the total animal community from which they hunt their prey. Specialist predators only eat certain types of prey, while opportunistic predators take all prey species available within a given size range. The European eagle owl (Bubo bubo) is usually considered a complete opportunist predator due to the varied nature of its diet. However, in the Iberian Peninsula, this large raptor shows a specialist behaviour, not observed in other countries from Europe. Its diet mainly consists of rabbits (Oryctolagus cuniculus), while brown rats (Rattus norvegicus), hedgehogs (Erinaceus europaeus) and hares (Lepus spp.) are alternatively consumed in areas of low rabbit abundance (Penteriani and Delgado, 2019). Considering these dietary preferences, small mammal assemblages accumulated by eagle owls in the Iberian Peninsula could be extremely biased, causing distorting effects in palaeoecological inferences. In this work, we analysed how the diet of eagle owls considerably varies in comparison with other nocturnal predators and how it may affect palaeoecological inferences from Iberian sites. A bibliographic review of the taxonomic diversity of small mammals from 28 eagle owl nests was compared with 23 barn owl nests (Tyto alba), an overall opportunist predator, in the southwest Iberia. Results indicated important differences between both predator assemblages. In general terms, the body mass of the prey spectra hunted by eagle owls is usually between 200 g and 2 kg, when lagomorphs are considered, and between 200-800 g considering only small mammals (< 1kg). Barn owls usually accumulated prey of less than 200 g, including incidentally some young rabbits. These results indicate that an important bias related to prey size intake is present and this fact may affect to palaeoecological inferences. Differences were also observed in the representation of the different taxonomic groups, with murids being the most frequent prey consumed by barn owls and arvicolines and glirids the best represented taxa in eagle owl assemblages when lagomorphs are not considered. These differences in prey assemblages from different predators were pointed out by Andrews (1990), which demonstrated the presence of differences between the prey spectra for three different predators hunting over the same area within one-time period. The application of the Habitat Weighting Method indicates different environmental conditions depending on the predator evaluated. Barn owl assemblages are dominated by open dry/humid environments and open woodland and open humid areas are best represented in eagle owl accumulations when lagomorphs are included in these analyses. On the 28 4th Meeting of the ICAZ Microvertebrate Working Group Tübingen (Germany) 8th 10th September 2022 contrary, in eagle owl prey assemblages in which only small mammals are considered wetland and woodland areas constituted more than the 50% of the habitats represented. These preliminary results highlight the necessity of applying taphonomic analyses prior to any palaeoecological inference. Likewise, knowing the feeding ecology of the predators in the different areas inhabited also plays a key role once a predator has been identified as the main accumulation agent of a small mammal assemblage

Rolling bones: A preliminary study of micromammal abrasion on different initial taphonomic stages

The identification of transport process is key to interpret the palaeoecology, the dating and the site formation. Apart from dispersal and size/shape selection, bone abrasion by water and sediment is an acquired taphonomic modification that makes transport recognizable in bone assemblages. Previous experiments with rodent bones used non-digested bones or emphasized abrasion on teeth to distinguish abrasion from digestion. Experiments with large mammals included different types of taphonomically modified bones. Following this procedure, two main aspects are here studied for the first time. On the one hand, we have focused on small mammal humeri and femora, which are also used to characterize digestion. We have also included different initial states or types of bones, such as digested, weathered or fossil bones to observe differences in abrasion behaviour that may help interpreting processes of water abrasion. On the other hand, we propose an easy test methodology to quantify the amount of surface loss. The resulting index to quantify surface loss shows light changes on bones abraded by clay and silts, in contrast to a more rapid and intense rounding of the salient angles by gravels. The latest yields a greater rounding and, therefore, surface loss, statistically significant. Cancellous tissues appear exposed after 72 hours of abrasion on proximal ends of femora and distal ends of humeri, mimicking corrosion produced by digestion. In this paper we describe key traits and quantify surface loss to distinguish between digestion and abrasion in postcrania, more specifically on proximal femora and distal humeri.This paper was funded by the project CGL2016-79334P of the Spanish Ministry of Research. SGM has a predoctoral grant from the Complutense University of Madrid (CT42/18-CT43/18)

Armadillo osteoderms altered by digestion and how taphonomy can help taxonomy

Diverse modifications of the original morphological features occur throughout the taphonomic history of osteological remains, which may lead in erroneous interpretations about the formation of an accumulation as well as taxonomic misidentifications. Here, we present a neo-taphonomic study in order to analyze and interpret the modifications generated by digestion on osteoderms of the armadillo Dasypus novemcinctus obtained from scats produced by Puma concolor. Results reveal intense breakage and modifications of the articular and broken edges, dorsal surface, bone tissues, and ornamentation pattern of the osteoderms. This work describes for the first time the modifications caused by digestion in armadillo osteoderms, improving the knowledge of preservation of this type of skeletal element and providing a modern analog that can be used to distinguish archeological and paleontological accumulations formed by predators from those generated by other processes. The recognition that digestion modifies the original ornamentation pattern is particularly significant because ornamentation features are used in nearly all taxonomic and phylogenetic studies of fossil cingulates. We use this new information to re-evaluate osteoderms recovered from carnivore coprolites of the classic Middle Miocene La Venta site (Colombia), which formed the basis for recognizing and characterizing the dasypodid species Nanoastegotherium prostatum. We highlight the importance of knowing with certainty the origin and taphonomic history of remains since, in the particular case of cingulates, taxonomic identification also has important biostratigraphic, paleoecological, paleoenvironmental, and paleobiogeo-graphical implications.This work was supported by projects PGI 24 H/154 (Universidad Nacional del Sur), G21()Universidad Nacional de La Pampa, and PUE-CONICET 229 20180100001. SGM has a predoctoral grant financed by the Universidad Complutense de Madrid and Banco Santander (CT42/18-CT43/18)Peer reviewe

Hyena as a predator of small mammals? Taphonomic analysis from the site of Bois Roche, France

Feeding behaviors may differ between past and current predators due to differences in the environments inhabited by these species at different times. We provide an example of this behavioral variability in spotted hyena (Crocuta crocuta), for which our analysis of a late Pleistocene micromammal assemblage indicates that hyenas preyed upon small rodents, a feeding habit that is rarely observed today among hyenas. The Bois Roche cave site is situated at the edge of a low bluff overlooking the floodplain of a small stream in Cherves-Richemont (Charente, France). The deposits are dated by electron spin resonance (ESR) to about 69.7 ± 4.1 Ka. Excavations at the site recovered fossil bones and teeth of large and small mammals, together with hyena coprolites. Water screening of the sediments produced large accumulations of rodent remains with low taxonomic diversity. Small mammal bones were recovered from hyena coprolites as well. Descriptions of small mammal bone modification, both from the sediments and coprolites, are reported here. The analysis yielded a distinct taphonomic pattern representative of large carnivores (over 30 kg), which differs from any other modern or fossil predator-accumulated microfaunal assemblage taphonomically analyzed to date. To our knowledge, previous studies of hyena diet have not recorded high concentrations of a single-rodent prey species. We conclude that the low species diversity of this small mammal assemblage most likely relates to a local abundance of the prey species due to an outbreak in the rodent population, rather than from specialist predator behavior and hunting technique.This investigation has benefited from projects CGL2007-66231 and CGL2016-79334P of the Spanish Ministry of Research. The Bois Roche excavations were funded by the French Ministry of Culture, the Leakey Foundation, the National Science Foundation, the General Council of the Charente Region, the Association of Archeologists of the Poitou-Charente Region, and Franklin and Marshall College.Peer Reviewe

Rodents, rabbits and pellets in a fluvial terrace (PRERESA site, Madrid, Spain)

The aim of this work is to study from a taphonomic view the small mammals assemblage located on the Pleistocene site known as PRERESA. The small mammal fossiliferous layer is a silt level located at a fluvial terrace. The samples studied included remains from rodents (Minimum Number of Elements: MNE=373) and lagomorphs (MNE=372). During the excavation seasons, a distinct high concentration of small mammals was recovered apart, named as fossil ‘pellet’. We consider this ‘fossil pellet’ to be an aggregation of several pellets and it has been taphonomically analyzed apart and included in this study. The presence of such concentrations/ aggregations is uncommon in this type of open-air sites. This aggregation contains 253 MNE fossil bones. The taphonomic study has considered three main aspects: anatomical representation, fragmentation, and corrosion by digestion. Due to the location of the site on a fluvial system, transport effects and abrasion were analyzed as well. The results obtained show a high representation of cranial elements (especially lagomorphs) as well as a high fragmentation of both cranial and postcranial elements. Digestion observed in this assemblage affects dental remains below 30% in both rodents and lagomorphs, being light and moderate digestion the most frequent degrees, but all samples reach extreme grades of digestion (in molars < 3%). Transport was analyzed using Voorhies groups (1969). All groups were present, even the easiest to transport. Group III (cranial remains) was the best represented. The simultaneous presence of all Voorhies groups suggests a low or null rate of transport. Results could indicate that the small mammal assemblage of PRERESA were produced by a nocturnal raptor, most likely an Eagle owl (Bubo bubo), whose nest or roosting site was installed near the fluvial channel

Assessment of the distribution of Pseudoryzomys simplex (Cricetidae, Sigmodontinae) in the Pampean region, central-east Argentina, in the late-Holocene

Pseudoryzomys simplex (Winge 1887) is a small to medium sized terrestrial oryzomyine rodent (Cricetidae, Sigmodontinae) widely distributed in humid environments of tropical and subtropical lowlands of South America with a marked rainy season. The occurrence of this species in the south-central Pampean region between 4700 and 200 ka cal BP was originally associated with some warm climatic episodes. A later hypothesis points out that P. simplex was a typical element of the Humid Pampa subregion during this period, whose distribution was retracted to the north due to the strong anthropic modifications in the area. To corroborate these hypotheses, the niche of occurrence of P. simplex was calculated to analyse the preferred climatic conditions of contemporaneous and fossil record of the species since 4700 ka cal BP. The derived climatic niche of P. simplex shows a marked preference for areas with seasonality precipitation patterns and tropical/subtropical conditions. Geographical estimations and climatic niches derived revealed a moderate overlapping between contemporaneous and Pampean late-Holocene projection, which in no case includes the localities where fossil data were found. Although a better comprehension of the ecological requirements of the species is necessary to discard a shift in its realized climatic niche, it is probable that P. simplex is able to maintain stable populations under similar conditions to the ones represented by fossil occurrences. The distribution of the species in the Humid Pampa subregion is probably affected by non-climatic factors today which are reducing its contemporaneous realized climatic niche and distorting the derived climatic niches obtained. These results support that this species cannot be considered a reliable palaeoclimatic indicator of more Brazilian conditions in the Humid Pampean subregion during the past.Peer reviewe