Abstract Initial peopling Holocene transition. While FTPsmake up 31% of recovered instruments, other toolsarepart North Patagonia of the site. In this work, the possible activities developed in the site are analyzed, based on the techno-morphological and morphological-functional analysis of the rest of the tools. A variety of typologicalgroups was recognized, where the set of bifaces, endscrapers and sidescrapers are found mostly represented. At the functional level, a low degree of integrity and little functional variability were recognized. These results allow us to sustain that the AW site would have functioned not only as an FTP re-equipment site, but also where other activities would have been carried out, such as the preparation of leather strips and shafts production and other activities mainly oriented to the preparation and conditioning of hunting equipment.

Resumen El sitio Amigo Oeste (AW), concentra el mayor registro de puntas Cola de Pescado (PCP) de Patagonia, artefactos diagnósticos del poblamiento temprano en América durante la transición Pleistoceno-Holoceno. Si bien las PCP constituyen el 31 % de los instrumentos recuperados, otros artefactos formatizados forman parte del sitio. En este trabajo se analiza las posibles actividades desarrolladas en el sitio, a partir del análisis tecno-morfológico y morfológico-funcional del resto de los artefactos formatizados. Se reconoció variedad de grupos tipológicos, donde el conjunto de bifaces, raspadores y raederas se encuentran mayormente representados. A nivel funcional, se reconoció un alto porcentaje de piezas con alteraciones postdepositacionales, bajo grado de integridad, y escasa variabilidad funcional. Estos resultados nos permiten sostener que el sitio AW habría funcionado no sólo como un lugar de reequipamiento de PCP, sino también, donde se habrían llevado a cabo otras actividades como la preparación de tientosy producción de astiles, actividadesprincipalmente orientadas a la preparación y acondicionamiento del instrumental para la caza.

Resumen Introducción: La variabilidad en la estructura de las comunidades acuáticas se atribuye frecuentemente a cambios ambientales, no obstante, en ambientes estables como ríos regulados, las interacciones tróficas podrían ser otro factor ambiental clave determinante de la estructura de estas comunidades. Estas alteraciones podrían provocar un mayor crecimiento de algas y, a su vez, cambios en los grupos funcionales y en la composición de la comunidad de macroinvertebrados favoreciendo la dominancia de determinados grupos de organismos. Objetivo: Identificar el efecto de los cambios ambientales y de la estructura del ficoperifiton sobre la comunidad de macroinvertebrados de ríos Andinos regulados. Métodos: Se analizaron datos ambientales y biológicos recolectados en muestreos trimestrales realizados entre 2010 y 2018 en dos ríos de los Andes Centrales (Antioquia - Colombia), para un total de 27 muestras. La recolección de muestras empleó métodos estandarizados. Se utilizaron diferentes modelos estadísticos para establecer patrones espaciales y temporales de las variables ambientales, de la abundancia y/o densidad y diversidad de ficoperifiton y de los macroinvertebrados, así como las relaciones tróficas que existen entre ellos. Resultados: Se encontró que los ríos regulados presentan relativamente poca variabilidad ambiental. Los parámetros ambientales con mayor variación fueron: temperatura, turbidez y ortofosfatos; las dos últimas variables abióticas fueron las que más aportaron a la inestabilidad bentónica. Conclusión: La presencia de macroinvertebrados raspadores y recolectores fue más afectada por la estabilidad de la densidad del ficoperifiton que por las variables ambientales, evidenciando la importancia de las interacciones tróficas en ríos regulados y el control bottoom up en estos ecosistemas.

Abstract Introduction: The variability in the structure of aquatic communities is frequently attributed to environmental changes; however, in stable environments such as regulated rivers, trophic interactions could be another key environmental factor determining the structure of these communities. These alterations could cause a greater growth of algae, and in turn, changes in the functional groups and in the composition of the macroinvertebrate community favoring the dominance of certain groups of organisms. Objective: To identify the effects of environmental variations and changes in the structure of the phycoperiphyton on the macroinvertebrate community of regulated Andean rivers. Methods: We analyzed environmental and biological data collected in quarterly samples carried out between 2010 and 2018 in two rivers of the Central Andes (Antioquia - Colombia), for a total of 27 samples. Sample collections used standardized methods. Different statistical models were used to establish spatial and temporal patterns of the environmental variables, of the abundance and/or density and diversity of phycoperiphyton and macroinvertebrates, as well as the trophic relationships that exists between them. Results: We found that regulated rivers present relatively little environmental variability. The environmental parameters with the greatest variation were temperature, turbidity, and orthophosphates; these last two were the abiotic variables with the greatest contribution to benthic instability. Conclusion: The presence of scraping and foraging macroinvertebrates was more affected by the stability of the phycoperiphyton density than by environmental variables, showing the importance of trophic interactions in regulated rivers and the bottom up control in these ecosystems.

Abstract: Aim We evaluated the effects of native vegetation and agricultural activities on functional characteristics of aquatic insects’ assemblages in Atlantic Forest streams southern Brazil. Methods We collected information on land uses, riparian zone structural characteristics, and limnological variables of ten streams to characterize their environmental quality. In the same streams, we collected aquatic insects (Ephemeroptera, Plecoptera, and Trichoptera) and determined their functional characteristics (e.g. food habits, mobility, shape, and body size). The information for each trait category was quantified using a fuzzy code technique. To test the environmental conditions on aquatic insect functional attributes, we used an RLQ analysis. Results In our study, only five environmental variables showed variation in streams (temperature, pH, DO, native vegetation, and agriculture use). We collected a total of 2591 organisms distributed in 21 EPT genera. We observed that the functional attributes of EPT formed distinct groups in relation to the stream categories defined by the measured environmental variables. We observed that shredders and larger and flattened organisms were associated with natural streams. These attributes were associated with the genera Phylloicus, Anacroneuria, Tupiperla, and Farrodes. On the other hand, we observed greater proportions of scrapers, with spherical bodies and shelter builders in streams impacted by agriculture. The most frequent genera in these streams were Itaura, Wormaldia and Helicopsyche. Conclusions The modification of natural landscapes by agricultural areas caused significant functional changes in the aquatic invertebrate communities. Since aquatic insects participate effectively in ecological processes, alterations in the functional characteristics of these communities can cause changes in the streams’ functioning. Abstract Brazil uses quality Ephemeroptera, Ephemeroptera (Ephemeroptera Plecoptera Trichoptera e.g. eg e g (e.g habits mobility shape size. size . size) technique analysis study temperature, temperature (temperature pH DO use. use use) 259 2 Phylloicus Anacroneuria Tupiperla Farrodes hand scrapers Itaura Helicopsyche processes functioning e.g 25

Resumo: Objetivo Neste estudo avaliamos os efeitos da vegetação nativa e atividades agrícolas sobre as características funcionais de assembleias de insetos aquáticos em riachos de Mata Atlântica, sul do Brasil. Métodos Coletamos informações sobre usos do solo, características estruturais da zona ripária e variáveis limnológicas de dez córregos para caracterizar sua qualidade ambiental. Nos mesmos riachos coletamos insetos aquáticos (Ephemeroptera, Plecoptera e Trichoptera) e determinamos as características funcionais (e.g., hábitos alimentares, mobilidade, forma, tamanho do corpo). A informação para cada categoria de característica foi quantificada usando uma técnica de código fuzzy. Para testar as condições ambientais nos atributos funcionais de insetos aquáticos, utilizamos uma análise RLQ. Resultados Em nosso estudo, apenas cinco variáveis ambientais apresentaram variação entre os riachos (temperatura, pH, DO, vegetação nativa, uso agrícola). Coletamos um total de 2591 organismos distribuídos em 21 gêneros das ordens EPT. Observamos que os atributos funcionais do EPT formaram grupos distintos em relação às categorias de riachos definidas pelas medidas das variáveis ambientais. Observamos que fragmentadores e organismos maiores e achatados estiveram associados a riachos naturais. Esses atributos foram associados aos gêneros Phylloicus, Anacroneuria, Tupiperla e Farrodes. Por outro lado, em riachos impactados pela agricultura, observamos maiores proporções de raspadores, com corpos esféricos e construtores de abrigos. Nesses riachos, os gêneros mais frequentes foram Itaura, Wormaldia e Helicopsyche. Conclusões A modificação das paisagens naturais por áreas agrícolas causou mudanças funcionais significativas nas comunidades de invertebrados aquáticos. Como os insetos aquáticos participam efetivamente dos processos ecológicos, alterações nas características funcionais dessas comunidades podem causar mudanças no funcionamento dos riachos. Resumo Atlântica Brasil solo ambiental Ephemeroptera, Ephemeroptera (Ephemeroptera Trichoptera e.g., eg g (e.g. alimentares mobilidade forma corpo. corpo . corpo) fuzzy RLQ temperatura, temperatura (temperatura pH DO agrícola. agrícola agrícola) 259 2 Phylloicus Anacroneuria Farrodes lado agricultura raspadores abrigos Itaura Helicopsyche ecológicos e.g. (e.g 25 e.g

ABSTRACT Laguna Las Vegas is a high integrity and high resolution site. It is a penecontemporaneous record that was formed around 3050-3210 BP which is remarkable due to the high frequency of guanaco bones (Lama guanicoe) and, to a lesser extent, of cauquén remains (Chloephaga sp.). Additionally, a highfrequency ofbonepounders and chalcedony scrapers was recorded. Wepropose that this site was a campsite originated by an attritionally discard behavior within a short time frame, in which whole preys (guanacos) were taken for processing, consumption, and subsequent transport of their axial skeleton. The fact that cauquén remains were found suggests that human occupations took place, at least, during spring and summer. Due to these features, Laguna Las Vegas stands out as a valuable site, one which adds useful information about faunal resource management and mobility of the hunter-gatherer populations of the Coyle River middle basin.

RESUMEN El sitio Laguna Las Vegas posee una alta integridad y resolución. Es un registro penecon- temporáneo formado alrededor de 3050-3210 años AP que se destaca por la alta frecuencia de restos de guanaco (Lama guanicoe) y, en menor magnitud, de cauquén (Chloephaga sp.), acom pañados principalmente por machacadores óseos y raspadores de calcedonia. Se postula que el sitio es el resultado del descarte en un campamento formado atricionalmente y en un corto lapso, al que habrían ingresado presas enteras (guanacos) para su procesamiento, consumo y ulterior transporte del esqueleto axial. La presencia de restos de cauquén indica que las ocupaciones humanas habrían tenido lugar, al menos, durante los meses de primavera y verano. Todas estas características lo definen como un sitio novedoso que añade valiosa información sobre el manejo de recursos faunísticos y la movilidad de poblaciones cazadoras-recolectoras en la cuenca media del río Coyle.

Abstract: The process of occupation of Santa Cruz province by the Argentinean State towards the end of the 19th century and during the early 20th century, involved its division in small units (estancias) and promoted the settlement of groups of European descent focused on sheep breeding. At the same time, specific areas (“reservations”) were created with the intention of constraining indigenous families. In this vein, we present archaeological evidence of four sites occupied during the 20th century by families of Tehuelche/ Aonikenk-Mapuche origin. The analysis focuses on architectonic features and glass scrapers. Two sites are located inside the former “reservation” area of Lago Viedma (“Cerro Índice”), while the other two sites are placed nearby at the Hotel Punta del Lago and near the former “reservation” of Camusu Aike (Coyle river basin). This evidence broadens the variability of archaeological contexts from Patagonia historical times and advances in the visualization of indigenous people.

Resumen: El proceso de ocupación estatal del espacio correspondiente a la actual provincia de Santa Cruz hacia finales del siglo XIX involucró su progresiva división en unidades productivas (estancias) y fomentó el establecimiento de grupos criollo-europeos orientados a la cría de ganado ovino. En forma paralela se fueron creando áreas de “reserva”1 destinadas al establecimiento de familias de origen indígena. En relación con este proceso se presenta la información correspondiente a cuatro sitios arqueológicos ocupados durante el siglo XX por familias de ascendencia Tehuelche/ Aonikenk-Mapuche. La evidencia material relevada se focaliza sobre estructuras arquitectónicas y raspadores de vidrio. Dos sitios están ubicados en la antigua “reserva” de Lago Viedma (“Cerro Índice”), otro cercano a la misma -en el Hotel Punta del Lago- y, el último, en la Laguna Puesto Peter, lindante con la antigua “reserva” Camusu Aike, en la cuenca media del río Coyle. La nueva información amplía la variabilidad de contextos arqueológicos de tiempos históricos en Patagonia, a la vez que colabora con la visualización de los pueblos originarios.

RESUMEN Se plantea como hipótesis que el arco y flecha y las boleadoras como sistemas de armas fueron empleados simultáneamente -en ambientes diferentes- entre los grupos cazadores-recolectores aonikenk post 1520 AD, contrariamente a lo planteado por el registro histórico-etnográfico. A fin de contrastar la hipótesis, y ante la escasez de bolas en estratigrafía para dicho momento, se propuso un análisis de frecuencias de puntas de proyectil, raspadores y raederas, provenientes de 38 sitios postcontacto. Estos tres tipos de artefactos presentaban diferentes frecuencias que podían ser asociadas a las distintas funcionalidades de los sitios (actividades limitadas vs. actividades múltiples). Este análisis, junto con la ubicación topográfica de los sitios, permitió contrastar positivamente la hipótesis inicial, mostrando la utilidad del análisis regional en momentos postcontacto.

ABSTRACT This paper proposes that the use of the bow and arrow and boleadoras (stone throwers) as a weapon system was simultaneously employed -in different environments- by the Aonikenk hunter-gatherer groups in the post 1520 AD period, which is different from the hypothesis found in previous historical-ethnographic studies. To test our hypothesis and due to the scarcity of stone balls in the stratigraphic excavations, we chose an analysis of the frequency of projectile points, end-scrapers and side-scrapers found in 38 post-contact sites. These three types of artefacts presented different frequencies, which may be associated with the different functions of the respective sites (limited activities vs. multiple activities). This analysis, together with the topography of the sites, allowed us to confirm our initial hypothesis, showing the usefulness of a regional approach to the analysis of post-Contact archaeology.

RESUMO Apresenta-se a hipótese de que sistemas de armas como o arco e flecha e as boleadeiras foram empregados simultaneamente -em ambientes diferentes- entre os grupos caçadores-coletores aonikenk após 1520 AD, contrariamente ao apresentado pelo registro histórico-etnográfico. A fim de contrastar a hipótese e diante da escassez de bolas em estratigrafia para tal momento, propôs-se uma análise de frequências de pontas líticas e diferentes tipos de raspadores provenientes de 38 locais pós-contato. Esses tipos de artefatos apresentavam diferentes frequências que podiam ser associadas às distintas funcionalidades dos locais (atividades limitadas versus atividades múltiplas). Esta análise, juntamente com a localização topográfica dos locais, permitiu contrastar positivamente a hipótese inicial, mostrando a utilidade da análise regional em momentos pós-contato.

Resumo Objetivo Queimadas é um distúrbio natural nas paisagens do Bioma Savana. Este estudo avalia os efeitos do pós-fogo (antes e depois) na decomposição de serapilheira na comunidade de invertebrados e biomassa de fungos em diferentes detritos e malhas (fina e grossa) em riacho em curto prazo temporal. Métodos Folhas senescentes (2 ± 0,1 g de peso seco) foram colocadas em sacos (30 × 30 cm, 10 mm – de malha grossa e 0,5 mm - de malha fina) e submersas no fluxo antes e depois do fogo. Sacos replicados (n = 4) foram recuperados após 20 e 40 dias e lavados em uma peneira para separar os invertebrados (densidade, riqueza e grupo trófico funcional) para ambos os tratamentos (antes e após o fogo). Uma série de discos das folhas foi cortada para determinar a massa seca isenta de cinzas e o material restante foi seco em estufa para determinar o peso seco. Resultados O coeficiente médio de decomposição (k = -0,012 dia-1 antes do fogo) corresponde ao intervalo intermediário observado em outros riachos de Savana, com valores menores no pós-fogo (k = -0,007 dia-1). Isso pode ser explicado pelo fogo diminuir a importância da serapilheira alóctone para metabolismo de fluxo devido a aumentar a produção de autóctones (maior abertura do dossel pela queima do mesmo). O coeficiente de decomposição intermediário de todas as diferentes espécies de folhas pós-incêndio pode indicar que o fogo pode equalizar a qualidade da serapilheira em ecossistemas de lóticos. Por outro lado, raspadores (e não fungos ou fragmentadores) pela função de fragmentação foliar (por consumo de perifíton) diminuíram sua abundância (30-50%) no pós-fogo como a perda de massa foliar. Conclusões Isso pode indicar que o pós-fogo modifica as relações de importância dentro das comunidades decompositoras em riachos tropicais.

Abstract Aim Wildfire is a natural pulsed disturbance in landscapes of the Savannah Biome. This study evaluates short-term post-fire effects on leaf litter breakdown, the invertebrate community and fungal biomass of litter from three different vegetal species in a tropical stream. Methods Senescent leaves of Inga laurina, Protium spruceanum and Rircheria grandis (2 ± 0.1 g dry mass) were individually placed in litter bags (30 × 30 cm: 10 mm coarse mesh and 0.5 mm fine mesh) and submerged in the study stream before and after fire. Replicate bags (n = 4; individually for each species, sampling time, fire event and mesh size) were then retrieved after 20 and 40 days and washed to separate the invertebrates before fire event and again immediately after fire. Disks were cut from leaves to determine ash-free dry mass, while the remaining material was oven-dried to determine dry mass. Results The pre-fire mean decomposition coefficient (k = -0.012 day-1) was intermediate compared to that reported for other savannah streams, but post-fire it was lower (k = -0.007 day-1), due to decreased allochthonous litter input and increased autochthones production. Intermediate k values for all qualities of litter post-fire may indicate that fire is equalizing litter quality in the stream ecosystem. The abundance of scrapers was found to be more important than fungal biomass or shredder abundance, probably due to their functioning in leaf fragmentation while consuming periphyton growing on leaf litter. Conclusions Theses results indicate that fire can modify the relationships within decomposer communities in tropical stream ecosystems.

Resumen Las quebradas están fuertemente influenciadas por su vegetación ribereña y la deforestación afecta a la comunidad acuática. Se estudiaron los efectos de la deforestación sobre la diversidad taxonómica y funcional del ensamblaje de macroinvertebrados acuáticos en cuatro quebradas Andinas colombianas. El estudio incluyó 12 sitios, siete de ellos con cobertura arbórea en sus márgenes en áreas boscosas no perturbadas por la deforestación (estaciones de referencia) y los otros cinco sin cobertura arbórea en áreas deforestadas (estaciones alteradas). Se realizaron cuatro muestreos de campo entre junio 2011 y febrero 2012 y se recolectaron muestras de macroinvertebrados bentónicos utilizando el método D-net con malla de 500 μm y recolección manual, y se midieron diferentes variables fisicoquímicas in situ. Se calcularon los índices de Shannon-Wienner (H ‘) y Simpson (D). Se aplicaron análisis unidireccionales de varianza ANOVAs a cada variable ambiental y análisis canónicos discriminantes (CDA). Se recolectaron un total 8 370 individuos correspondientes a 80 taxones durante el estudio. La abundancia y diversidad fue mayor en las estaciones localizadas en áreas boscosas no perturbadas. Thraulodes, Anacroneuria y Rhagovelia, se asociaron con valores más altos de Calidad de Bosque de Ribera Andina (QBR-And), Índice de Hábitat Fluvial (IHF), Biological Monitoring Working Party Colombia (BMWP/Col) y temperatura en estaciones de referencia, mientras que Leptonema, Baetodes y Mayobaetis se asociaron con mayores valores de pH y altura sobre nivel del mar en estaciones alteradas. Los principales grupos funcionales tróficos (GFT) en las estaciones de referencia fueron colectores-recolectores/raspadores (27.2 %), raspadores (25.4 %) y depredadores (24.4 %), mientras que en estaciones alteradas fueron: Colectores filtradores (27.5 %), colectores-recolectores/raspadores (17.4 %) y raspadores (15.7 %). Los hábitos de vida más abundantes en las estaciones de referencia fueron agarradores (50.5 %), taxones con tres o más hábitos (28.7 %) y patinadores (16.1 %), mientras que en las estaciones alteradas fueron agarradores (68.1 %), taxones con tres o más hábitos (13.7 %) y excavadores (5.2 %). El conocimiento de las variables que determinan la estructura taxonómica y funcional de los ensamblajes de macroinvertebrados, y cómo responden a impactos como la deforestación, puede ayudar a determinar acciones de protección o restauración de las condiciones ambientales y ecológicas de las quebradas Andinas y los hábitats riparios.

Abstract The creeks are strongly influenced by their riparian vegetation, and the deforestation affect the aquatic community. The effects of deforestation on taxonomic and functional diversity of aquatic macroinvertebrate assemblage in four Colombian Andean creeks were evaluated. The study included 12 sites, seven of them with arboreal coverage at their margins in forested areas undisturbed by deforestation (reference stations) and the other five without tree cover in deforested areas (altered stations). Four field samplings were carried out between June 2011 and February 2012, and samples of benthic macroinvertebrates were collected using the D-net method with 500 μm mesh and manual collection, and different physicochemical variables were measured in situ. The Shannon-Wienner (H′) and Simpson´s index (D) were calculated. One-way analyses of variance (ANOVAs) to each environmental variable, and canonical discriminant analysis (CDA) to establish differences in environmental variables, taxonomic and functional diversity between references and altered stations were applied. 8 370 macroinvertebrate individuals corresponding to 80 taxa were collected in the study, with 6 758 individuals and 75 taxa in references stations and 1 612 individuals and 50 taxa in altered stations. The reference stations had higher values of diversity and the taxa that made major contributions to the variance between reference and altered stations were Thraulodes, Anacroneuria and Rhagovelia, which were associated with the highest values of Index of Andean riparian vegetation Quality (QBR-And), fluvial habitat index (IHF), Biological Monitoring Working Party Colombia BMWP/Col, EPT index (Ephemeroptera, Plecoptera, and Trichoptera) and temperature in reference stations, whereas Leptonema, Baetodes and Mayobaetis were associated with higher pH and elevation above sea level in altered stations. The main functional feeding groups (FFG) at the reference stations were collectors-gatherers/scrapers CG / SC (27.2 %), scrapers SC (25.4 %) and predators PR (24.4 %), and for altered stations were collectors-filterers CF (27.5 %), collectors-gatherers/scrapers CG / SC (17.4 %) and scrapers SC (15.7 %). The most abundant life habits were clingers Cg (50.5 %), taxa with three or more habits (28.7 %) and skaters Sk (16.1 %), in the reference stations, and clingers Cg (68.1 %), taxa with three or more habits (13.7 %) and burrowers Bu (5.2 %) in the altered stations. The knowledge of the variables that determine the taxonomic and functional structure of the macroinvertebrate assemblages, and how they respond to impacts such as deforestation, can help to determine actions of protection or restoration of the environmental and ecological conditions of the Andean streams and the riparian habitats.

In the framework of the analysis of the prehistoric occupations registered in rock shelters from the north coast of Santa Cruz, stratigraphic studies were carried out at the Alero 4 site. In this sense, an excavation was carried out on a surface of approximately 2m², which presented a stratigraphy depth of approximately 40 cm. A high frequency of lithic artifacts was recorded, among which were mainly flakes. Also, it is interesting to highlight the identification a high frequency of scrapers, which is a finding of relevance in virtue of the studies carried out to date in the area. The trends observed in the techno-morphological study of the pieces indicate the existence of certain geographical restrictions in the procurement and exploitation of the rocks used to made and use the scrapers. In this paper we intend to complement and discuss the information by virtue of the data generated in the functional analysis of the pieces, which somehow contradict said affirmation. In addition, the studies will evaluate the site's functionality within the framework of the settlement system and the mobility of the groups that occupied the area and generate new discussions regarding the scope of the technology of coastal hunter-gatherers.

En el marco de los análisis de las ocupaciones prehistóricas registradas en abrigos rocosos de la costa norte de Santa Cruz, se efectuaron estudios estratigráficos en el sitio Alero 4. En este sentido, se realizó una excavación en una superficie de aproximadamente 2m², la cual presentó una potencia estratigráfica de aproximadamente 40 cm. Se registró una alta frecuencia de artefactos líticos, entre los que se diferenciaron principalmente productos de talla. Asimismo, resulta interesante resaltar la identificación de una alta frecuencia de raspadores, la cual constituye un hallazgo de relevancia en virtud de los estudios realizados hasta el momento en el área. Las tendencias observadas previamente en el estudio tecno-morfológico de las piezas indicarían la existencia de ciertas restricciones geográficas en cuanto al aprovisionamiento y explotación de las rocas empleadas para confeccionar y utilizar los raspadores. En el presente trabajo se pretende complementar y discutir dicha información en virtud de los datos generados en el análisis funcional de las piezas, los cuales de alguna manera contradicen dicha afirmación. Asimismo, los estudios permitirán evaluar la funcionalidad del sitio en el marco del sistema de asentamiento y movilidad de los grupos humanos que ocuparon el área y generar nuevas discusiones en cuanto a los alcances de la tecnología de los cazadores-recolectores costeros.

RESUMEN Los insectos acuáticos son indicadores ecológicos de perturbación antrópica y actualmente existe una tendencia a explorar el enfoque funcional como herramienta para la evaluación de la calidad del agua. Los insectos pueden cambiar el modo y tipo de adquisición de alimento de acuerdo con las condiciones del medio. Se evaluó la influencia del impacto agrícola y minero sobre la diversidad, los grupos funcionales alimentarios y gremios tróficos de insectos acuáticos en la cuenca alta del río Chinchiná (Caldas, Colombia). Se eligieron dos localidades una minera y otra agrícola, y en cada una se evaluaron dos quebradas, una de referencia y otra impactada. Mediante red Surber se recolectaron 8239 individuos agrupados en ocho ordenes, 36 familias y 71 taxones (Cn=100%). Se analizó el contenido intestinal de los individuos de los nueve géneros más abundantes y según el porcentaje de material ingerido se clasificaron como: fragmentadores, recolectores, depredadores, raspadores y filtradores. El tipo de alimento no cambió entre zonas de referencia e impactadas, los recolectores fueron dominantes en el área de estudio, seguidos por los fragmentadores. La mayor diversidad estuvo asociada a las quebradas no impactadas. No se evidenciaron cambios en la dieta de los insectos acuáticos, posiblemente debido a la disponibilidad de recursos. La actividad agrícola presentó el efecto negativo más fuerte sobre la diversidad del grupo, lo que puede estar asociado tanto con la extensión de los cultivos hasta las quebradas, con la consecuente pérdida de la vegetación ribereña y con el uso de agroquímicos.

ABSTRACT Aquatic insects are ecological indicators of human disturbance and currently there is the tendency to use the functional approach as a potential tool to evaluate water quality. Insects can change the food acquisition mode and the type according to environmental conditions. This study aims to evaluate the influence of the agricultural and mining impacts upon the diversity and dominance of aquatic insect feeding functional groups and trophic guilds found upstream in the Chinchiná River (Caldas, Colombia). Two localities were selected, one with mining and one with agriculture activities, in each locality we evaluated a reference and an impacted creek. A total of 8239 individuals were collected using a Surber net; these are grouped into eight orders, 36 families and 71 morphospecies (Cn=100%). The intestinal content of the specimens whom belong to the nine most abundant genera of aquatic insects was analyzed and classified as: shredders, collectors, predators, scrapers, and filterers. No changes were noted regards to the diet between impacted and reference areas, possibly due to resource availability. Agricultural activity presented the strongest negative effect on the diversity of the group. This result may be linked to the complete loss of riparian vegetation due the immediate proximity of the crops to the studied streams, and to the use of agrochemicals.

RESUMO Lauxaniidae é uma das maiores famílias de Diptera Schizophora, com distribuição mundial, muito abundante nas áreas tropicais. A família está composta por cerca de 1.550 espécies. Os adultos apresentam o corpo pequeno a relativamente grande (2-11 mm), com coloração variada, muitas vezes com marcas, manchas, listras ou padrões reticulados. As larvas são conhecidas como saprófagas, alimentando-se em uma variedade de matéria vegetal em decomposição e mesmo em capítulos de flores. Adultos são raspadores de fungos em folhas. A fauna brasileira de Lauxaniidae compreende, até o momento, 74 espécies das quais 8 possuem registro assinalado para o estado do Mato Grosso do Sul.

ABSTRACT Lauxaniidae is one of the largest Diptera Schizophora families, worldwide in distribution, very common in tropical areas. The family comprises about 1,550 species. Adults may be small to moderately large (2-11 mm), varied in color patterns, often with marks, spots, bands, or reticulating patterns. Larval lauxaniids are widely documented as saprophages, feeding in a diverse array of decaying plant matter, and even feeding in flower heads. Adults are fungal grazers on leaves. The Brazilian fauna of lauxaniids comprises at the moment 74 species of which 8 have been recorded from the state of Mato Grosso do Sul.

O Leste da América do Sul, ou o que é hoje o território brasileiro, coloca questões interessantes sobre a ocupação humana no início das Américas. Três tecnologias líticas totalmente distintas e contemporâneas, datadas entre 11.000 e 10.000 14C AP, estão presentes em diferentes partes do país: a tradição Umbu no sul, com sua indústria formal bifacial, com raspadores bem retocados e pontas bifaciais; a tradição Itaparica no centro-oeste e nordeste, totalmente unifacial, cujos únicos artefatos formais são os raspadores plano-convexos; e a indústria de "Lagoa Santa", com ausência completa de quaisquer artefatos formais, composta principalmente por pequenas lascas de quartzo. Nossos dados sugerem que estas diferenças não estão relacionadas à subsistência ou restrições de matéria-prima, mas sim a diferentes normas culturais e transmissão cultural de cadeias operatórias fortemente divergentes. Essa diversidade na cultura material, quando abordada do ponto de vista da teoria da transmissão cultural (TC), parece em desacordo com um modelo simples de origem Clovis destas três tradições culturais, dado o tempo decorrido desde as primeiras idades Clovis e da estrutura populacional esperada para os primeiros colonizadores da América do Sul.

Eastern South America, or what is today Brazilian territory, poses interesting questions about the early human occupation of the Americas. Three totally distinct and contemporaneous lithic technologies, dated between 11,000 and 10,000 14C BP, are present in different portions of the country: the Umbu tradition in the south, with its formal bifacial industry, with well-retouched scrapers and bifacial points; the Itaparica tradition in the central-west / northwest, totally unifacial, whose only formal artifacts are limaces; and the "Lagoa Santa" industry, completely lacking any formal artifacts, composed mainly of small quartz flakes. Our data suggests that these differences are not related to subsistence or raw-material constraints, but rather to different cultural norms and transmission of strongly divergent chaînes opératoires. Such diversity in material culture, when viewed from a cultural transmission (CT) theory standpoint, seems at odds with a simple Clovis model as the origin of these three cultural traditions given the time elapsed since the first Clovis ages and the expected population structure of the early South American settlers.

Bioerosion trace fossils can shed light on the ecological interactions between species. Here we describe an unusual case of bioerosion on a turtle carapace of Hispaniachelys prebetica from the Oxfordian (around 155 Ma, Upper Jurassic) of the Prebetic (Betic Cordillera, South Spain). The specimen was found in a limestone bed of a marl-limestone rhythmite. Morphological analysis of the bioerosive structures reveals the dominance of epigenic traces produced by the grazing activity of regular sea urchins (ichnospecies Gnathichnus pentax). No other bioerosion structures are present. From an ethologic point of view only epigenic traces (pascichnia) are present. Gnathichnus pentax records short-term bioerosion produced exclusively on the carapace before its burial. The ichnological assemblage recorded herein typifies the Gnathichnus Ichnofacies. The carapace was the most favourable hard substrate for grazers in comparison to the surrounding muddy soft bottom. The carapace was oriented convex-down when found in the rock. Therefore, pascichnial activity probably occurred early after the death and accumulation on the sea floor of the turtle remains, but before the carapace was overturned by large scavengers. The low degree of fragmentation and the low dispersion of skeletal components indicate a low-energy environment and early burial in the sea bottom.

Las pistas fósiles de bioerosión son una herramienta útil para interpretar las relaciones ecológicas entre especies. En este trabajo se describe un caso poco habitual de bioerosiones en un caparazón de tortuga (Hispaniachelys prebetica) del Oxfordiense (Jurásico superior, hace aproximadamente 155 Ma) del Prebético (Cordillera Bética, S España). El especimen fue hallado en un banco calizo en una ritmita margoso-calcárea. El análisis morfológico de las estructuras bioerosivas revela la presencia de numerosas pistas epigénicas producidas por organismos raspadores, concretamente erizos regulares (ichnospecie Gnathichnus pentax). Gnathichnus pentax registra periodos cortos de bioerosión producidos exclusivamente sobre el caparazón previamente a su enterramiento. La asociación registrada tipifica la icnofacies de Gnathichnus. El caparazón fue el sustrato duro más favorable para los erizos irregulares raspadores en comparación con el fondo blando circundante. El caparazón se encontró en el afloramiento en posición invertida dentro de la capa caliza. Así, la colonización del mismo probablemente ocurrió en una fase temprana, tras la muerte del organismo y su acumulación en el fondo, pero antes de que el caparazón fuera girado a una posición invertida, probablemente por la acción de grandes carroñeros. El bajo grado de fragmentación y la escasa dispersión de los elementos del esqueleto apuntan a una baja energía en el medio así como un enterramiento relativamente rápido.