Ten sediment cores (2.0-8.5 m long) from various locations in Lake of the Woods (LOTWs) and Shoal Lake (SL) were recovered in August 2006, using a Kullenberg piston corer. From the study of the macrofossils (primarily ostracodes and thecamoebians) and the sediments in six processed cores, variations in paleoconditions were observed both spatially and temporally, and the timing of these changes were identified in over 10,000 years of postglacial history. Ostracodes disappeared from the LOTWs record from about 9000 to 7600 calendar years before present (BP) (about 5800 in SL), after LOTWs became isolated from glacial Lake Agassiz. Thecamoebians appeared in many cores around 2000 calendar years BP, with the earliest appearance at 9200. Buried paleosols in three cores indicate portions of the lake dried on several occasions during the Hypsithermal, perhaps indicating the region’s future climate response. One core contained a pink clay bed indicative of the Marquette readvance about 11,300 years (BP), and the subsequent input of water from the Superior basin.

The intracontinental endorheic Aral Sea, remote from oceanic influences, represents an excellent sedimentary archive in Central Asia that can be used for high-resolution palaeoclimate studies. We performed palynological, microfacies and geochemical analyses on sediment cores retrieved from Chernyshov Bay, in the NW part of the modern Large Aral Sea. The most complete sedimentary sequence, whose total length is 11 m, covers approximately the past 2000 years of the late Holocene. High-resolution palynological analyses, conducted on both dinoflagellate cysts assemblages and pollen grains, evidenced prominent environmental change in the Aral Sea and in the catchment area. The diversity and the distribution of dinoflagellate cysts within the assemblages characterized the sequence of salinity and lake-level changes during the past 2000 years. Due to the strong dependence of the Aral Sea hydrology to inputs from its tributaries, the lake levels are ultimately linked to fluctuations in meltwater discharges during spring. As the amplitude of glacial meltwater inputs is largely controlled by temperature variations in the Tien Shan and Pamir Mountains during the melting season, salinity and lake-level changes of the Aral Sea reflect temperature fluctuations in the high catchment area during the past 2000 years. Dinoflagellate cyst assemblages document lake lowstands and hypersaline conditions during ca. 0–425 AD, 920–1230 AD, 1500 AD, 1600–1650 AD, 1800 AD and since the 1960s, whereas oligosaline conditions and higher lake levels prevailed during the intervening periods. Besides, reworked dinoflagellate cysts from Palaeogene and Neogene deposits happened to be a valuable proxy for extreme sheet-wash events, when precipitation is enhanced over the Aral Sea Basin as during 1230–1450 AD. We propose that the recorded environmental changes are related primarily to climate, but may have been possibly amplified during extreme conditions by human-controlled irrigation activities or military conflicts. Additionally, salinity levels and variations in solar activity show striking similarities over the past millennium, as during 1000–1300 AD, 1450–1550 and 1600–1700 AD when low lake levels match well with an increase in solar activity thus suggesting that an increase in the net radiative forcing reinforced past Aral Sea’s regressions. On the other hand, we used pollen analyses to quantify changes in moisture conditions in the Aral Sea Basin. High-resolution reconstruction of precipitation (mean annual) and temperature (mean annual, coldest versus warmest month) parameters are performed using the “probability mutual climatic spheres” method, providing the sequence of climate change for the past 2000 years in western Central Asia. Cold and arid conditions prevailed during ca. 0–400 AD, 900–1150 AD and 1500–1650 AD with the extension of xeric vegetation dominated by steppe elements. Conversely, warmer and less arid conditions occurred during ca. 400–900 AD and 1150–1450 AD, where steppe vegetation was enriched in plants requiring moister conditions. Change in the precipitation pattern over the Aral Sea Basin is shown to be predominantly controlled by the Eastern Mediterranean (EM) cyclonic system, which provides humidity to the Middle East and western Central Asia during winter and early spring. As the EM is significantly regulated by pressure modulations of the North Atlantic Oscillation (NAO) when the system is in a negative phase, a relationship between humidity over western Central Asia and the NAO is proposed. Besides, laminated sediments record shifts in sedimentary processes during the late Holocene that reflect pronounced changes in taphonomic dynamics. In Central Asia, the frequency of dust storms occurring during spring when the continent is heating up is mostly controlled by the intensity and the position of the Siberian High (SH) Pressure System. Using titanium (Ti) content in laminated sediments as a proxy for aeolian detrital inputs, changes in wind dynamics over Central Asia is documented for the past 1500 years, offering the longest reconstruction of SH variability to date. Based on high Ti content, stronger wind dynamics are reported from 450–700 AD, 1210–1265 AD, 1350–1750 AD and 1800–1975 AD, reporting a stronger SH during spring. In contrast, lower Ti content from 1750–1800 AD and 1980–1985 AD reflect a diminished influence of the SH and a reduced atmospheric circulation. During 1180–1210 AD and 1265–1310 AD, considerably weakened atmospheric circulation is evidenced. As a whole, though climate dynamics controlled environmental changes and ultimately modulated changes in the western Central Asia’s climate system, it is likely that changes in solar activity also had an impact by influencing to some extent the Aral Sea’s hydrology balance and also regional temperature patterns in the past. <hr> The appendix of the thesis is provided via the HTML document as ZIP download. / Der Aralsee ist ein intrakontinental gelegenes endorheisches Gewässer fernab von ozeanischen Einflüssen, welches ein exzellentes sedimentäres Archiv für hochauflösende Paläoklimastudien in Zentralasien darstellt. In der vorliegenden Studie wurden umfangreiche palynologische, mikrofazielle und geochemische Analysen anhand von mehreren Bohrkernen aus der Chernyshov-Bucht im NW des heutigen Großen Aralsees durchgeführt. Die vollständigste der erbohrten Sequenzen weist dabei eine Länge von 11 m auf und beinhaltet näherungsweise die letzten 2000 Jahre des Holozän. Die hochauflösenden palynologischen Analysen der Studie, welche sowohl die Untersuchung von Dinoflagellatenzysten als auch Pollen beinhaltet, zeugen von einschneidenden Umweltveränderungen im Aralsee und seinem Einzugsgebiet. Die Untersuchung von Diversität und räumlicher Verbreitung der fossilen Dinoflagellatenzysten vermittelt dabei ein genaues Bild von den Salinitäts- und Seespiegeländerungen der letzten 2000 Jahre. Aufgrund der weitgehenden Abhängigkeit der hydrologischen Verhältnisse des Aralsees von der Wasserführung seinen tributären Flüsse, hängt sein Seespiegel unmittelbar von den Schmelzwasserzuflüssen im Frühjahr ab. Da der Schmelzwasserzufluss seinerseits mit den Temperaturveränderungen im Tien Shan und Pamir während der Schneeschmelze in Verbindung steht, spiegeln die Paläo-Salinität und der Paläo-Seespiegel des Aralsees folglich die Temperaturveränderungen im hochgelegenen Einzugsgebiet des Aralsees wider. Die Untersuchung der fossilen Dinoflagellatenzysten belegt besonders niedrige Seestände und hypersaline Bedingungen während der Perioden 0–425 AD, 920–1230 AD, 1500 AD, 1600 AD, 1800 AD und seit 1960, wohingegen oligohaline Bedingungen und höhere Seestände zwischen diesen Phasen dokumentiert sind. Ferner stellen umgelagerte Dinoflagellatenzysten aus Paläogenen und Neogenen Ablagerungen wertvolle Proxies für den Beleg von extremen Flächenspülereignissen dar, wie sie beispielsweise 1230–1450 AD aufgetreten und durch sehr hohe Niederschläge dokumentiert sind. Anhand der in der Studie erarbeiteten Daten ist davon auszugehen, dass die am Aralsee nachgewiesenen Umweltveränderungen im Wesentlichen von klimatischen Änderungen induziert wurden, durch historischen Bewässerungsfeldbau oder militärischen Konflikten jedoch noch verstärkt werden konnten. Darüber hinaus zeigen die Seestandsveränderungen eine sehr hohe Korrelation mit der Sonnenaktivität im letzten Jahrtausend, wie etwa während den Perioden 1000–1300 AD, 1450–1550 und 1600–1700 AD. Komplementär zu der Untersuchung von Dinoflagellatenzysten liefert die Pollenanalyse wertvolle Klimadaten für das Becken des Aralsees. Verschiedene Temperatur- (Jahresmittel, kältester gegen wärmster Monat) und Niederschlagsparameter wurden mit Hilfe der Methode der „probability mutual climatic spheres“ quantitative ausgewertet, womit die Klimaentwicklung im westlichen Zentralasien der letzten 2000 Jahre nachvollzogen werden konnte. Kalte und aride Bedingungen wiesen demnach die durch trockenangepasste Vegetation und Steppenelementen geprägten Perioden 0–400 AD, 900–1150 AD und 1500–1650 AD auf. Andererseits traten warme und weniger aride Klimabedingungen in den durch niederschlagsbedürftigere Pflanzen gekennzeichneten Zeiträumen 400–900 AD and 1150–1450 AD in den Vordergrund. Die Studie zeigt für das Becken des Aralsees, dass die Veränderungen im Niederschlagsmuster hauptsächlich vom zyklonalen System des östlichen Mittelmeergebietes (EM) gesteuert werden, welches den nahen Osten und das westliche Zentralasien mit Feuchtigkeit im Winter und Frühjahr versorgt. Da seinerseits das EM maßgeblich von Luftdruckänderungen der Nordatlantischen Oszillation (NAO) während seiner negativen Phase reguliert wird, ist ein Zusammenhang zwischen der Feuchtigkeit im westlichen Zentralasien und dem NAO anzunehmen. Außerdem belegen die laminierten Sedimente Veränderungen in den Sedimentationsprozessen während des späten Holozän, sowie ausgeprägte Änderungen im taphonomischen Verhalten. In Zentralasien hängt die Häufigkeit der im Frühjahr auftretenden Staubstürme hauptsächlich von der Intensität und der Position des Sibirienhochs (SH) ab. Der Gehalt an Titanium (Ti) als Proxy für äolischen Eintrag in den laminierten Sedimenten erlaubt die Rekonstruktion von winddynamischen Veränderungen in Zentralasien in den letzten 1500 Jahren. Die Studie beinhaltet daher die bislang längste Analyse der Variabilität des SH. Hohe Titaniumwerte sprechen für eine stärkere Winddynamik während den Perioden 450–700 AD, 1210–1265 AD, 1350–1750 AD und 1800–1975 AD, und dokumentieren demzufolge eine stärker ausgeprägtes SH während des Frühjahrs. Umgekehrt belegen geringe Titaniumwerte für die Zeit von 1180–1210 AD, 1265–1310 AD, 1750–1800 AD und 1980–1985 AD einen reduzierten Einfluss des SH.

Ten sediment cores (2.0-8.5 m long) from various locations in Lake of the Woods (LOTWs) and Shoal Lake (SL) were recovered in August 2006, using a Kullenberg piston corer. From the study of the macrofossils (primarily ostracodes and thecamoebians) and the sediments in six processed cores, variations in paleoconditions were observed both spatially and temporally, and the timing of these changes were identified in over 10,000 years of postglacial history. Ostracodes disappeared from the LOTWs record from about 9000 to 7600 calendar years before present (BP) (about 5800 in SL), after LOTWs became isolated from glacial Lake Agassiz. Thecamoebians appeared in many cores around 2000 calendar years BP, with the earliest appearance at 9200. Buried paleosols in three cores indicate portions of the lake dried on several occasions during the Hypsithermal, perhaps indicating the region’s future climate response. One core contained a pink clay bed indicative of the Marquette readvance about 11,300 years (BP), and the subsequent input of water from the Superior basin.

South-western Australia is a globally significant hotspot of plant species diversity, with high endemism and many rare plant species. Proteaceae is a major component of the south-western flora, though little is known about how its diversity developed. This prompted the present study to investigate changes in the abundance and diversity of Proteaceae, in south-western Australia, by concurrently studying three sediment sequences of different ages over the Cainozoic and a modern pollen rain study. Modern pollen-vegetation relationships in the two Proteaceae species rich nodes of the northern and southern sandplains were quantified. It was found that Proteaceous genera can contribute up to 50% of the total pollen rain. Banksia/Dryandra pollen was the most abundant with Isopogon, Petrophile and Lambertia also commonly noted. The vegetation and environmental setting during three pivotal periods of the Cainozoic: Holocene, Pliocene and Eocene, were investigated. Eocene sediment from Lake Lefroy confirmed the presence of a Nothofagus dominated rainforest in the Middle to Late Eocene. At this time Proteaceae species were at least as diverse as today, if not more so, contributing up to a maximum of 42% of the total pollen rain. Taxa recorded included: Banksieaeidites arcuatus, Propylipollis biporus, Proteacidites confragosus, Proteacidites crassus, Proteacidites nasus and Proteacidites pachypolus. Several taxa remain undescribed and unnamed. This study also identified that Proteaceae pollen representation varies across small lateral distances. Thus as samples varied spatially and temporally, single core samples are not sufficient to identify spatial patterns in Proteaceae or other low pollen producing taxa. Some 7.91 cm of laminated Pliocene sediment from Yallalie, south-western Australia, was also examined. It covers 84 years of record and confirmed other regional reports that south-western Australia was covered by a rich vegetation mosaic consisting of heathy and wet rainforest elements. Although Proteaceae species were a consistent component of the pollen counts, diversity and abundance (maximum of 5%) was low throughout the studied section. Banksia/Dryandra types were most commonly noted. A 2 m core was retrieved from Two Mile Lake, near the Stirling Ranges and provided an early Holocene vegetation history. Geochemical and palynological evidence recorded little change, suggesting the environment of deposition was relatively uniform. Proteaceae species were noted throughout the core, though in low numbers, at a maximum of 3.5 % of the total pollen rain. Banksia/Dryandra was the most abundant while Isopogon, Lambertia, Petrophile and Franklandia were also noted. A regression model was developed through the modern pollen rain study to predict the number of Proteaceae in the vegetation. This was also applied to the fossil pollen records. The estimated number of Proteaceae species in the Eocene suggests a maximum of 20 and a minimum of 10 taxa. For the Pliocene record, an estimated 7 - 9 species was found and for the Holocene pollen, between 7 - 8 were present. Thus the Eocene was similar in Proteaceae diversity to today. The results from the Pliocene and Holocene suggest that Proteaceae diversity was lower than today. Findings of this research indicate that Proteaceae species are an important and consistent component of vegetation in south-western Australia over the Cainozoic. It is likely that both changing pollination mechanisms and changes in associated vegetation are important in the determining the dispersal of Proteaceaous pollen. By understanding how the vegetation has changed and developed in south-western Australia, present vegetation can be managed to include intra-specific variation and ensure the majority of species are conserved for present and future generations to enjoy.

Les industries lithiques de l’Holocène moyen, entre 8.000 et 4.000 BP dans le centre et le nord-est du Brésil ont souvent été décrites non pas en fonction des caractères présents mais de ceux absents : absence de lesma (pièce façonnée unifacialement), absence de céramique. Les traits techniques spécifiques à la période sont difficiles à cerner à cause de la diversité des artefacts. Décrites comme peu élaborées ou simples, ces industries interrogent pourtant par leurs caractères extrêmement différents de ceux de la période antérieure. Des hypothèses liées à des facteurs externes ont été évoquées pour expliquer de tels changements dans la culture matérielle : changement climatique avec une forte modification de l’environnement, remplacement de la population par une nouvelle vague de peuplement. Toutefois, il est difficile d’évaluer les modalités de cette rupture tant les analyses sur des assemblages de la période sont peu nombreux. Nous proposons dans ce travail de caractériser les systèmes techniques de l’Holocène moyen et par ce biais aborder le phénomène de rupture technique avec le technocomplexe Itaparica. Deux assemblages lithiques de l’Holocène moyen ont été étudiés selon une approche techno-fonctionnelle : la Toca Nova do Inharé dans la Serra da Capivara (Piauí) et le site Cajueiro (BA-RC-19) au nord-est du plateau central (Bahia).Les résultats obtenus mettent en évidence l’existence de caractères partagés et de variabilités importantes. L’organisation des différentes parties fonctionnelles des outils, structurée par la présence récurrente de pans abrupts, constitue un caractère commun fort. Les supports d’outils sont en revanche très variables selon les sites, expliquant cette impression d’absence d’outils clairement définis déjà soulignée.La confrontation de nos résultats aux données disponibles dans la littérature nous a permis d’affirmer ces caractères comme une spécificité des industries de l’Holocène moyen et de confirmer également l’existence d’une rupture technique importante avec le technocomplexe Itaparica. / During middle Holocene, between 8000 and 4000 BP, central and northern Brazil lithic industries were often described in terms of lacks more than tangible characteristics: lacks of “lesma” (unifacial shaping tool), lacks of ceramics. Specific technical features linked to that period are not easy to pinpoint because of a high level of artifacts diversity. Described as somewhat elaborate or simple, the specific nature of these industries highlights differences between this period and the previous one. To explain such a change in material culture, external factor hypothesis were proposed: huge environment modification due to climate change, new population that replaces another one. However, it is uneasy to evaluate break modalities regarding few studies on these period assemblages.Our work proposes to characterize the technical systems for the middle Holocene, and, by this way, to broach the technical break phenomenon using Itaparica techno-complex. Two middle Holocene lithic assemblages were study in a techno-functional way: la Toca Nova do Inharé, in Serra da Capivara (Piauí) and the Cajueiro site (BA-RC-19) northeastern of the central plateau (Bahia). Results reveal shared characteristics and significant variability. Organization of different functional parts of tools outlined around recurrent presence of abrupt sides, form a strong shared feature. Tool blanks have, however, high degree of variability according to different sites, explaining the lack of strictly defined tools. Our results compared to available literature data allow us to confirm that these features are specific to these middle Holocene industries and also to bear out the existence of a significant technical break with the Itaparica techno-complex.

Vaste plateau de grès découpé d'innombrables vallées sèches au sein du Sahara oriental, le Gilf el-Kebir a servi de zone refuge pendant l'optimum holocène, d'environ 8000 à 4000 avant notre ère. Les données archéologiques permettent de restituer les pratiques quotidiennes et les stratégies de moyen ou long terme des groupes ayant fréquenté la région pendant cet intervalle. L'habitat et la mobilité, la gestion des ressources et approvisionnements et l'organisation des activités sont autant de témoins de la relation de l'homme à son environnement, et de la façon dont il l'exploite pour ses besoins. Au Gilf el-Kebir, l'appropriation de la nature se traduit en termes matériels et idéels. Au VIe millénaire avant notre ère, l'adoption du pastoralisme implique des changements sur le plan de l'économie domestique, de l'organisation sociale et des symboles. Sur les parois des abris du nord-ouest, l'art rupestre traduit en images la façon dont l'homme conceptualise sa place et son rôle au sein de son environnement. Les figurations atypiques de bêtes mi-homme mi-animal participent à notre compréhension des procès de socialisation de la nature. / With its foothills carved by numerous dry valleys, the sandstone plateau of the Gilf el-Kebir has been used as a refuge area in the Eastern Sahara during the Holocene optimum, from around 8000 to 4000 Be. Archaeological data allow understanding the daily practices and also the medium- and long-term strategies of the groups who settled in the region. Housing and mobility, management of resources and procurement and organization of the activities are ail witnesses of the relationship of man to his environment, and how he uses it for his needs. In the Gilf el-Kebir, the appropriation of nature is reflected in the material and conceptual fields. During the VIth millennium BC, the adoption of cattle pastoralism involves changes both in domestic economies and in social and symbolic life. In the northwestern shelters, rock art translates into images the conception that the painters and the engravers had of their own place and role among their environment. The atypical representations of half-human half-animal beasts take part in our understanding of the process for socializing nature.

Four continuous high-resolution peat records for the Holocene have been reconstructed across a ~300km transect from Shebster in Caithness to Yell in the Shetland Isles. These records describe the nature and extent of North Atlantic climate changes inferred from indicators of storminess and minerogenic aeolian dust, and are supported by radiogenic isotope analysis, tephrochronology and radiocarbon dating. The environmental changes at all four sites displays a significant degree of synchrony in response to changes in the position of the polar front jet (PFJ) stream and the phase of the North Atlantic Oscillation (NAO). Bromine concentrations in the peat, derived from sea spray, are used to reconstruct storm frequency and storm intensity, and mire surface wetness is used as an indicator of longer-term climate shifts. The results suggest a strong link between positive phases of the NAO and storminess. Subtle differences between the bromine concentrations and the mire surface wetness suggest that high intensity but perhaps less frequent periods of storminess are not necessarily associated with a wetter climate. Atmospheric minerogenic dust concentrations are used to reconstruct large-scale climate changes across the wider North Atlantic region. The results suggest a sympathy between dust activity and periods of glacial advance and a negative index of the NAO. Radiogenic isotope analysis suggests that the smallest particles may originate from Iceland.

This article presents key data and discussion about the initial peopling of northwestern South America, highlighting its strategic significance in the continental context, cultural variability and landscape change over time. In Colombia there is very little relevant information regarding occupations prior to 12,000 BP; in contrast, the information is abundant relative to a number ofearly contexts during the Pleistocene-Holocene transition. The variability among unifacial and bifacial lithic assemblages reported in different physiographic regions indicates alternative models on early settlement to regional level. Considering the importanceof the inter-Andean valley of the Magdalena River, this article emphasizes the archaeological contexts and paleoenvironmental information, highlighting environmental impacts associated not only to global climate change, but in particular of the effects ofvolcanism. The article stresses the findings and chronologies of bifacial lithic assemblages of the Magdalena Valley in relation to the early archaeology of northwestern South America. / En este artículo se presentan los principales datos y reflexiones asociados al poblamiento inicial del noroccidente de Sudamérica debido a su significado estratégico en el marco continental, se destacará la variabilidad cultural y se enfatizarán los cambios depaisajes en el transcurso del tiempo. En Colombia existe muy poca información relevante relacionada con las ocupaciones anterioresa 12.000 AP; en contraste, la información es abundante en cuanto al número de contextos tempranos durante la transición Pleistoceno-Holoceno. La variabilidad entre los conjuntos líticos unifaciales y bifaciales reportados en distintas regiones fisiográficas plantea propuestas de modelos alternativos sobre el poblamiento temprano a escala regional. Considerando la importancia del valle interandino del río Magdalena, se recalcan los contextos arqueológicos e información paleoambiental. Asimismo, se destacan los impactos ambientales que demuestran por qué no perduraron las evidencias del Pleniglacial, lo que podría deberse a efectos asociados no solo al cambio climático global, sino, en particular, a causa del vulcanismo. Este trabajo resalta los hallazgos y cronologías de los conjuntos líticos bifaciales del valle del Magdalena en relación con la arqueología temprana del noroccidente de Sudamérica.

Palaeoenvironmental reconstruction of the late Pleistocene and Holocene geological periods for central and southern Africa has been hampered by the erratic distribution of suitable sites, incomplete and inaccurately dated sequences and the limited nature of published data. One geomorphological feature which has supplied valuable evidence for fluctuations in past environmental conditions, is the vlei or dambo. The type-site of these waterlogged features is in south central Africa, but similar features have been described on other continents. The clastic and organic sediments contained within these features are affected by, and therefore reflect to some degree, the environment under which they were formed. The characteristics of the sediments supply information as to their transport and mechanisms of deposition. From these processes, the environmental conditions at the time of vlei formation can be inferred. The environmental history of the Eastern Cape region has been considerably neglected, and is far less well understood than other countries such as Malawi, Zambia and Zimbabwe. A study site in the Winterberg Range (Eastern Cape) was selected which permitted the comparison of two vleis, the objective being to establish an accurate late Pleistocene sediment chronology for the entire plateau area. Radiocarbon dates from organic layers indicate that these sediments span the last 12 000 years BP, suggesting that organic accumulation at this site began at roughly the same time as at sites further afield. The vlei sediments are analysed in terms of their morphology, particle slze distribution, and other physical and chemical characteristics. These data facilitate the construction of detailed stratigraphic diagrams and a chronological summary of sediment accumulation, from which the period and governing processes of vlei development under changing environments may be described. It is found that the Winterberg vleis contain sediments which respond to changes in the prevailing environment. This makes these sediments useful indices from which to trace such changes during the late Pleistocene and Holocene times. These features are found to be similar in many respects to those described elsewhere in Southern Africa. The study attempts to provide greater understanding of contemporary vlei processes and emphasises the necessity of their preservation, as finite and valuable resources, by future generations

Nas últimas décadas os estudos sobre mamíferos fósseis do Brasil aumentaram significativamente, mas ainda assim pouco se conhece sobre o registro daqueles de pequeno porte (Didelphimorphia, Chiroptera e Rodentia, Hystricognathi). Apesar destes serem registrados para onze estados brasileiros, as ocorrências são muito pontuais e fragmentárias, exceto pela fauna de Lagoa Santa, Estado de Minas Gerais. Estudou-se os mamíferos de pequeno porte de dois sítios arqueológicos com datações que abrangem desde o Holoceno inicial (± 9.400 anos AP) até o Holoceno final (± 3.700 anos AP). Os sítios localizam-se na porção nordeste do estado, nos Municípios de Montenegro e Santo Antônio da Patrulha, no limite entre duas sub-regiões biogeográficas neotropicais, a Chaquenha e a Paranaense. Além da taxonomia, também estudou-se aspectos paleoclimáticos e paleoambientais para as duas áreas. Registrou-se 24 táxons de mamíferos de pequeno porte, sendo eles: Gracilinanus agilis, G. microtarsus, Monodelphis americana, Thylamys velutinus, Thylamys cf. T. velutinus, Didelphis sp., Philander opossum (Didelphidae), Chrotopterus auritus, Pygoderma bilabiatum (Phyllostomidae), Eptesicus brasiliensis, Eptesicus fuscus, Myotis cf. Myotis ruber, Vespertilionidae aff. Lasiurus (Vespertilionidae); Tadarida brasiliensis, Molossus molossus (Molossidae), Cavia sp., C. aperea, C. magna (Caviidae), Ctenomys sp. (Ctenomyidae), Myocastor coypus (Myocastoridae), Phyllomys sp., Euryzygomatomys mordax, Dicolpomys fossor e uma nova espécie, Clyomys sp. nov. (Echimyidae). A composição da fauna de pequenos mamíferos em ambos os sítios, especialmente em relação aos Echimyidae, evidencia uma similaridade taxonômica com a fauna de Lagoa Santa. Entre os táxons registrados, pelo menos três deles estão extintos (D. fossor, E. mordax e Clyomys sp. nov), o que poderia indicar uma maior diversidade dos Echimyidae durante o Holoceno, assim corroborando a hipótese de extinções mais tardias da fauna de roedores na região mais ao norte da América do Sul do que no extemo sul deste continente. Em relação ao paleoclima, a fauna de marsupiais e roedores caviomorfos manteve-se quase a mesma ao longo do tempo em ambas as áreas, o que pode ter-se devido a mudanças climáticas mais lentas e graduais. A ocorrência de marsupiais e roedores caviomorfos de ambientes campestres e áreas florestadas nos mesmos níveis poderia dever-se a um ambiente em mosaico, mas com predomínio dos campos. A diferença temporal no início da expansão das florestas entre as duas áreas, a qual é hipotetizada pelos dados palinológicos, não pôde ser corroborada pelo registro dos mamíferos de pequeno porte, já que desde o Holoceno inicial (± 8.000 anos AP) estavam presentes em ambos os sítios animais típicos de áreas florestadas. Os Chiroptera não contribuiram para com as análises paleoambientais e paleoclimáticas devido à sua distribuição estratigráfica irregular e o pequeno número de espécimes. As inferências paleoclimáticas e paleoambientais embora preliminares, são as primeiras com vistas ao melhor entendimento do Holoceno do Estado do Rio Grande do Sul. / During the last decades, there was an increase in the studies about the fossil mammals from Brazil, although very little is known about the record concerning those of small size (Didelphimorphia, Chiroptera e Rodentia, Hystricognathi). Although these animals are recorded for eleven Brazilian states, most occurrences are isolated and fragmentary, except from Lagoa Santa, Minas Gerais State. Small mammals from two archaeological sites were studied, dating from the Early Holocene (± 9,400 years BP) until the Late Holocene (± 3,700 years BP). The sites are in the Northeast of Rio Grande do Sul State, at Montenegro and Santo Antônio da Patrulha Counties, situated at the boundary of two neotropical biogeographic subregions, Chaco and Parana. Besides from taxonomy, there were also studied paleoclimatic and paleoenvironmental aspects of both areas. There were recorded 24 taxa of small mammal: Gracilinanus agilis, G. microtarsus, Monodelphis americana, Thylamys velutinus, Thylamys cf. T. velutinus, Didelphis sp., Philander opossum (Didelphidae), Chrotopterus auritus, Pygoderma bilabiatum (Phyllostomidae), Eptesicus brasiliensis, Eptesicus fuscus, Myotis cf. Myotis ruber, Vespertilionidae aff. Lasiurus (Vespertilionidae); Tadarida brasiliensis, Molossus molossus (Molossidae), Cavia sp., C. aperea, C. magna (Caviidae), Ctenomys sp. (Ctenomyidae), Myocastor coypus (Myocastoridae), Phyllomys sp., Euryzygomatomys mordax, Dicolpomys fossor and a new species, Clyomys sp. nov. (Echimyidae). The small mammal fauna composition from the two sites, mainly that of Echimyidae, made evident a taxonomic similarity with the fauna from Lagoa Santa. Among the taxa recorded, at least three of them are extinct (D. fossor, E. mordax and Clyomys sp. nov), what might indicate a greater diversity of Echimyidae during Holocene, in this way corroborating the hypothesis of rodent extinctions occurring much later northern than in southern South America. Concerning paleoclimatic aspects, the composition of the marsupials and caviomorphs was quite the same over time in both areas, indicating that climatic changes during the Holocene were possibly slow and gradual. The occurrence of marsupials and caviomorphs of grasslands and other ones of forested areas at the same levels incates a mosaic environment, but with grasslands predominance. The temporal difference in the beggining of forest expansion in both areas, which is hypothetized by the palynological data, could not be corroborated on the basis of the small mammals, because since Early Holocene (± 8,000 years BP) forest animals were present at both sites. Data on the Chiroptera did not contribute to the paleoclimatic and paleoenvironmental analyses, because of their irregular stratigraphic distribution and small number of specimens. The paleoclimatic and paleoenvironmental inferences although preliminary, are the first contribution to a better understanding of Holocene of Rio Grande do Sul State.