a mid pleistocene in situ fossil brown hyaena parahyaena brunnea latrine from gladysvale cave south africa abstract an in situ fossil latrine is reported from gladysvale cave south africa the latrine area is c 1 5 m in observable horizontal length and varies in height with a maximum of 20 cm indicating that deposition may have occurred over a considerable period of time the size of individual coprolites in the latrine varies with larger specimens 30 mm in diameter but the majority generally smaller c 15 20 mm the overall size and morphology of the coprolites and latrine are consistent with modern parahyaena brunnea which inhabit the caves today dated to between 195 and 257 ka the latrine indicates that troglodytic latrine making behaviour in p brunnea may be traced to at least the late middle pleistocene of southern africa

dated evidence of the interaction between humans and megafauna in the late pleistocene of sergipe state northeastern brazil abstract we present a radiocarbon date 12 742 12 562 cal bp for an eremotherium laurillardi tooth found in sergipe state northeastern brazil which shows anthropogenic marks our result provides additional information and reinforces the hypothesis that humans was present in south america earlier than accepted currently and interacted with megafauna during the late pleistocene in this region

unveiling the taphonomy of elusive natural tank deposits a study case in the pleistocene of northeastern brazil abstract fossiliferous natural tanks are a singular type of sedimentary deposit restricted to northeastern brazil which usually preserves a diversified late pleistocene vertebrate fauna their fossil assemblages are taxonomically well known but their taphonomy is poorly understood this work presents a detailed taphonomic analysis of a tank deposit from jirau site ceara state northeastern brazil to improve understanding of the processes that influenced fossil deposition and preservation in natural tanks and to shed light on paleoecological and paleoenvironmental aspects related to the late pleistocene vertebrate fauna from northeastern brazil tank deposits from different localities were also compared to figure out potential taphonomic patterns among them additionally comparisons with other brazilian pleistocene deposits and other debris flow deposits bearing vertebrates were undertaken the study revealed the predominance of the megamammal eremotherium laurillardi in the deposit which we attributed to its abundance in late pleistocene biocoenosis as well as bone resistance scarcity of non mammalian vertebrates is likely related to their paucity in late pleistocene biocoenosis time averaging was evidenced by the co occurrence of different weathering petrographic and color patterns and may have affected the ontogenetic profile of the accumulation relative to the original biocoenosis analyses of weathering stages tooth and trample marks indicate wide exposition of the thanatocoenosis before burial abrasion and petrographic patterns allow reworking in the assemblage to be inferred permineralization and substitution are the fossilization processes observed taphonomy indicates that floods deposited clasts and bioclasts in the tank under an arid or semiarid climate in a debris flow regime comparison with other tank deposits revealed several similar taphonomic features and differences related to sedimentology and stratigraphy taphonomic similarities suggest rather homogeneous environmental conditions in the northeastern brazil during the late pleistocene as previously suggested by taxonomic studies comparison with other brazilian pleistocene deposits shows that tanks have more temporal fidelity than caves coastal and some fluvial deposits the jirau vertebrate accumulation was produced by the reworking and transport of skeletal elements accumulated in a nearby thanatocoenosis and is similar to other better known debris flow hosted vertebrate accumulations

the quaternary vertebrate fauna of the limestone cave gruta do ioio northeastern brazil o quaternary pleistocene bahia brazil cave deposits abstract the present study reports the quaternary vertebrate fauna of gruta do ioi a partially submerged limestone cave located in central bahia northeastern brazil a semi arid weather prevails nowadays in the area which is mostly covered by a xeric low arboreal scrubland known as caatinga the identified taxa include rhamdia osteichtyes siluriformes caiman crocodyliformes caimaninae myocastor cf myocastor coypus rodentia myocastoridae holochilus sciureus rodentia sigmodontinae natalus cf natalus macrourus chiroptera natalidae tonatia bidens trachops cirrhosus chiroptera phyllostomi dae and eira cf eira barbara carnivora mustelidae whereas rhamdia and caiman have scarce fossil records the recovered mammals have already been reported from quaternary localities of northeastern brazil although only two of them are present in the current local fauna taphonomic signatures and the nature of the fossiliferous site indicate that the vertebrates lived inside or nearby the cave including the swamp by its main entrance radiocarbon dating of dental bioapatite yielded calibrated ages between 19 980 and 22 040 bp this indicates that the accumulation started at least during the late pleistocene within the last glacial maximum in agreement with the mode of life of most taxa recognized here previous studies indicated that this was a wetter period in the region

taphonomic analysis of a late pleistocene vertebrate accumulation from lage grande paleontological site pernambuco state northeastern brazil new remarks on preservational aspects of tank deposits biological stratigraphic and temporal processes act on the origin of fossil concentrations the influence of these phenomena on fossil vertebrate accumulations from tank deposits recently began to be analyzed in detail this paper documents taphonomic patterns recognized in the late pleistocene fossil vertebrate accumulation from a tank deposit of lage grande paleontological site lgps pernambuco state northeastern brazil the preservation observed in lgps differs strongly from the expected for tank accumulations and given the high quality of preservation and the low rate of time averaging inferred indicated by the low degrees of surface bone modifications it seems reasonable that lgps accumulation reflects nearly non biased biocenotic patterns under this hypothesis eremotherium laurillardi was the most abundant species in the region of lage grande during the late pleistocene similarly to other areas with tank deposits surprisingly cingulates were rare or absent non mammalian vertebrates and glossotherium were rare in that area taphonomic signatures indicate that the thanatocoenosis of lage grande experienced a short time span of subaerial exposure prior to burial and short transport to inside the tanks by debris flows thus lgps accumulation can be classified as parautochthonous besides the inferred rapid burial of the lgps assemblage when compared to other tank accumulations another feature that may had generated the peculiar taphonomic setting of lgps accumulation is the uncommon pond like morphology of this deposit morphology of the tanks may be one additional factor responsible for differential preservation of vertebrates in this kind of deposit

holocene survival of late pleistocene megafauna in china a critical review of the evidence late quaternary megafaunal extinction chronologies are poorly understood across eastern and southeast asia previous radiometric studies suggested that surprisingly many extinct late pleistocene large mammal species survived into the holocene in northern china bos primigenius coelodonta antiquitatis mammuthus primigenius and southern china ailuropoda baconi crocuta crocuta ultima megatapirus augustus stegodon orientalis sus cf xiaozhu indicating that chinese megafaunal extinctions may have been staggered across the late quaternary we critically re examined all radiometric evidence suggesting holocene survival of chinese late quaternary megafauna and conducted new dating of mammal material from reportedly holocene sites containing characteristically late pleistocene faunas evidence for holocene survival of any chinese late pleistocene megafaunal species is weak or untenable no previous radiometric dates used to support holocene megafaunal survival represent direct bone dates for species of interest and stratigraphic association between material yielding holocene dates and megafaunal remains is dubious at most sites concerns over accurate identification of faunal material further confuse claims for holocene survival of many species robust radiometric last occurrence dates for extinct chinese megafauna are all restricted to the late pleistocene similar to the timing of many other late quaternary megafaunal species extinctions elsewhere in eurasia and the americas c 2013 elsevier ltd all rights reserved

u series dating of bone using the diffusion adsorption model abstract u series dating of bone has suffered problems of reliability since its inception because bone remains an open system with respect to uranium commonly applied a priori assumptions of u uptake such as early uptake or linear uptake are inadequate because they have no physical or chemical bases no means of demonstrating which model is suitable for a particular bone and no intrinsic tests of reliability despite this and numerous examples of anomalous u series dates such assumptions are still routinely applied we address this problem using the diffusion adsorption d a model of u uptake millard and hedges 1996 which incorporates a physicochemical description of u uptake using this model we show how the u uptake of a bone responds to geochemical changes in the burial environment which can lead to phenomena such as the removal of u from bones leaching or u uptake late in their burial history recent uptake and we show how the overall uptake history is reflected in distributions profiles of u and u series isotopes across a bone section we present measurements of u concentration profiles and 230 th 234 u profiles on archeological bone from a number of different sites and burial environments and compare the results to profiles predicted by the d a model bones that have undergone complex uptake histories which include u leaching or recent uptake are identified on the basis of these profiles and rejected as unsuitable for dating for bones that appear to have undergone uptake under constant geochemical conditions the d a model is applied to calculate u series dates with much improved reliability

cyclic sedimentation in brazilian caves mechanisms and palaeoenvironmental significance abstract caves associated with doline slopes in the tectonically stable area of eastern brazil display remarkable sequences of clastic sediment intercalated with calcite layers sediment erosion has also occurred allowing access to formerly sediment filled passages the palaeoenvironmental meaning and chronology of these three processes i e clastic sediment input clastic sediment erosion and speleothem precipitation were studied in both semi arid campo formoso and sub humid lagoa santa areas through 230 th dating and stratigraphical analyses the dry climate of the campo formoso area prevents speleothem deposition at present but soil erosion results in valley aggradation and cave infilling growth periods of speleothems and travertines in this area have allowed the recognition of recurrent past phases of increased humidity correlated with wet conditions recorded in southeastern brazil speleothem calcite at the lagoa santa area there is limited speleothem precipitation and sediment input at present however sediment entrainment is actively exhuming speleothems and exposing cave passages sediment erosion inside caves in the area is interpreted as being due to intermediate climatic conditions not wet enough to favour speleothem deposition and not too dry to allow doline slope erosion and sediment transport into caves due to the low rates of denudation and isostatic rebound inherent to tectonically stable areas cave passages will remain within the range of sediment infill and erosion for a much longer time than in tectonically active areas spanning in average at least three full glacial interglacial cycles as uplift proceeds cave passages will be decoupled from the doline bottom and no longer will be affected by erosion or infilling episodes sediment filled passages in many caves in the lagoa santa region are relict features that display ancient clastic and chemical precipitation the three processes described above have occurred throughout the life history of the caves resulting in complex sediment assemblages that can however show significant intra and inter site variations

stratigraphical and palaeontological data from the early pleistocene pirro 10 site of pirro nord puglia south eastern italy the pirro nord palaeontological and archaeological locality has been the object of recent field research to investigate the fossil content of its early pleistocene vertebrate palaeocommunities and to understand the genesis of the karst network and related deposits that delivered the lithic industry representing the earliest human occupation of europe known so far spanning 1 7e1 3 ma the succession of the pirro 10 site has been described in terms of facies and fossil vertebrate content of the 37 distinguished sedimentary units su on the whole the succession is made of chemical and clastic sediments that include debris fall and alluvial deposits su are distinguished according to lithology colour discontinuities lamination fossil concentration and taphonomical parameters palaeomagnetic data and biochronological characteristics refer the pirro 10 site to the latest late villafranchian mammal age of the italian biochronological mammal scale the fossil content is quite homogenous common taxa are axis eurygonos hystrix refossa ursus etruscus canis mosbachensis together with small mammal remains mainly represented by chiroptera and the arvicolid microtus allophaiomys e x gr ruffoi a significant change in the taxonomic record occurs in

a new record of a scelidotheriine ground sloth xenarthra mylodontidae from central brazil quaternary cave stratigraphy taxonomy and stable isotopes abstract an upper fourth molariform of a scelidotheriine ground sloth is reported from carneiro cave which is located in the karstic region of serra da mesa goias in this limestone cave the tooth was found at the base of a depositional sequence associated with a 2 m thick debris flows deposit which is covered by the lowest carbonate crust dated at approximately 200 000 yr bp detailed morphological description stable isotope data and stratigraphic context are provided this represents the first megafauna record for this region of central brazil where this record is found in direct association with a diverse microvertebrate fauna

identification and importance of critical depositional gaps in pitfall cave environments the fossiliferous deposit of cuvieri cave eastern brazil abstract the majority of extinct brazilian late quaternary mammal i e megafauna remains comes from cave deposits and was retrieved through excavations lacking detailed stratigraphical context this poses a major problem since these deposits present multifaceted processes of formation based on the meticulous excavation of a pitfall site within cuvieri cave minas gerais eastern brazil this article describes a critical albeit subtle temporal discontinuity between different fossiliferous sedimentary facies and discusses its significance to the contextualization of the paleontological remains recovered from the site the discontinuity was described based on sedimentary analyses bone deposition processes taxonomy and ams radiocarbon chronology two facies were distinguished and named according to their color and texture an upper dark brown silt loam bsl and a lower dark reddish brown silt loam rbsl besides color differences they present differences in grain size distribution and chemical composition these analyses show that the rbsl has in its composition only half the sand and one third more the silt than bsl it also shows that mean percent values for the rbsl in comparison to the bsl are higher for silica 42 35 versus 15 80 aluminum 18 63 versus 7 58 and iron 8 45 versus 3 79 and lower for calcium 10 07 versus 36 14 and volatiles 13 86 versus 30 10 these differences are attributed to changes in sediment source and entrance route differences were also observed in the faunal remain analyses rbsl has abundant megafauna remains originally deposited within this facies while the scarce megafauna material found in bsl is the result of mixing processes despite these differences animal entrapment is considered the best scenario to explain bone accumulation in both facies ams radiocarbon dates indicate that the bsl was deposited during the holocene with dates ranging from 8580 cal yr bp to the present while the rbsl deposition dates to the holocene pleistocene transition 13 600 10 660 cal yr bp radiocarbon dating also indicates that the subtle erosional surface that limits both facies represents a temporal gap between a minimum age of 8 4 cal kyr bp and a maximum age of 11 0 cal kyr bp the recognition of this discontinuity allows for a more accurate interpretation of bone accumulation enabling the differentiation of faunal assemblages that might otherwise be considered part of a continuum

isotopic paleoecology δ13c from mammals from iuiu ba and paleoenvironmental reconstruction δ13c δ18o for the brazilian intertropical region through the late pleistocene abstract stable isotopes of carbon and oxygen of fossil specimens are widely used for paleoecological and paleoenvironmental inferences and there has been an effort to better understand the isotopic paleoecology and chronology of herbivores that inhabited the brazilian intertropical region during the late quaternary in the present work new radiocarbon datings and carbon and oxygen isotopes data for eremotherium laurillardi notiomastodon platensis tapirus terrestris tayassu pecari and mazama gouazoubira are presented from specimens that lived on iuiu county toca fria and jatoba caves state of bahia in the brazilian intertropical region e laurillardi was dated as of 32 ka bp representing the oldest direct dating for this species in the brazilian intertropical region while n platensis was dated as of 25 ka bp fossils of the extant species t pecari m gouazoubira and t terrestris presented radiocarbon ages of 23 ka bp 21 ka bp and 15 ka bp respectively showing that some of these species lived in iuiu during the last glacial maximum according to our analyses t terrestris was the only specialist 13c 11 0 pic3 0 76 ba 0 49 whereas the remaining taxa were generalists mixed feeders 13c 1 3 to 10 0 pic3 0 24 to 0 69 ba 0 58 the paleoenvironment reconstruction in iuiu and other localities in bir during 32 ka bp to 15 ka bp allow us to suggest that the dry arboreal to open savanna habitats rich in grass and shrubs were the most common environment

megafauna from the late pleistocene holocene deposits of the upper ribeira karst area southeast brazil abstract the carbonate caves of the upper ribeira valley southeastern sao paulo state brazil preserve an abundant fossil record of pleistocene holocene south american megafauna nevertheless in comparison with other localities of the country its paleontological knowledge still can be considered sparse and in need of further research this work presents an update taxonomic survey of the megafauna material collected since the beginning of the explorations in the area based on this it discusses paleobiogeographic and paleoecological questions the fossil megafauna of the upper ribeira karst region include eremotherium laurillardi nothrotherium maquinense lestodon armatus catonyx cuvieri ocnopus gracilis ahytherium aff aureum glyptodon clavipes g reticulatus hoplophorus cf toxodon spp stegomastodon waringi equidae hippidion cf tapirus terrestris panthera onca and smilodon populator only p onca and t terrestris still remain in the region despite the occurrence of some typical taxa of the pampean paleobiogeographical province the fossil assemblage recorded shows greater affinity to the mega mammal community of the intertropical region the ecology of species found suggests the previous occurrence of fairly different environmental settings than the existing one in the area there were more temperate climates both dry and wet until the current mesophytic forest was finally established the studied material does not show any kind of chrono correlation given the type of genesis of the cave accumulations these fossils depict different faunistic moments related to climate changes during the quaternary to better understand the information provided by these deposits efforts on dating and detailed taphonomic investigations should be conducted the studies of the quaternary fauna in the state of sao paulo fill an important gap in the intricate biogeographical history of the south american megafauna

calcareous nannofossils and milankovitch cycles the example of the albian gault clay formation southern england a quantitative study of calcareous nannofossil assemblages was carried out on the albian gault clay formation england this unit consists of grey marly claystones and marlstones with phosphatic nodules and glauconitic layers as minor lithologies two cores were analyzed in detail to focus on changes in nannofloral assemblages and consider their significance preservation of calcareous nannofossils is excellent and therefore diagenesis cannot be invoked to explain not even partially the changes registered in assemblages fast fourier spectral analysis was performed on percentages of selected nannofossil species fluctuations in abundance of both biscutum constans and watznaueria barnesae regarded as fertility and non fertility indices respectively appear to be orbitally driven because spectral analysis showed periodicities of approximately 41 kyr obliquity cycle and 100 kyr short eccentricity cycle in all the spectra the axial obliquityc cycle is a strong signal as expected at these high latitude sites from the boreal realm the same pattern was observed in another fertility controlled taxon zygodiscus cf erectus but cross correlation shows that its abundance plot is displaced with respect to that of b constans orbital perturbations induce variations in climate and ocean circulation because they influence the earth s insolation and seasonality during times of high seasonality strong gradients cause vigorous oceanic circulation a better cycling of nutrients and higher fertility whereas during times of low seasonality low gradients induce more sluggish circulation and lower fertility the carbonate content of the gault clay cores is not correlatable to the higher fertility indices as the abundance curves of b constans w barnesae and z cf erectus are displaced with respect to caco3 content variations this also means that cyclicity in nannofossil assemblages is not a result of diagenesis but an original signal abundance fluctuations of repagulum parvidentatum and combined parhabdolithus asper p splendens colder and warmer water indicators respectively provide evidence for orbital periodicities suggesting that also cyclic variations of surface water temperature might have influenced the nannofossil assemblage patterns within the gault clay

reconstructing diagenetic conditions of bone at the gray fossil site tennessee usa abstract the preservation of vertebrate fossils requires transformation of the original bioapatite mineral matrix predominantly hydroxylapatite during diagenesis into a thermodynamically more stable phase fossil bone geochemistry and structure provides a wealth of information on the conditions present during diagenesis including site redox and ph and about sedimentation rates during burial the gray fossil site preserves late neogene lacustrine deposits that serve as one of a few records of north american paleoclimate during a critical period of the cenozoic despite having 40 vertebrate species and diverse plant assemblages none of the prior studies used bone composition to understand what paleoenvironmental and diagenetic conditions must have been like to facilitate bone preservation and fossilization alligator sp phalanges were examined using multiple geochemical tools including fourier transform infrared spectroscopy x ray diffraction and electron microprobe analyses evidence of bioerosion within thin cortical and isolated trabecular regions of bone suggests biotic utilization of organics collagen and or the mineral s following deposition chemically zoned and laminated cortical alligator bone is interpreted as preserved lines of arrested growth that developed during life and supports previous interpretations of a regional seasonal climate lastly the alligator bones are mineralogically heterogeneous as fluorinated and iron containing apatite phases compared to modern bone iron concentrations were high at up to 3 wt the uptake of fe by the alligator bones examined in this study suggests that fluids present during diagenesis that led to bone preservation within the lacustrine sediment at the gray fossil site were likely acidic anoxic and reducing

extended range luminescence chronologies suggest potentially complex bone accumulation histories at the early to middle pleistocene palaeontological site of huescar 1 guadix baza basin spain abstract the palaeontological site of huescar 1 contains a diverse faunal assemblage and has played an important role in establishing local scale biozone successions in the guadix baza basin here we provide the first ages for the fossil bearing deposits at this site using a suite of extended range luminescence dating approaches including optically stimulated luminescence osl of quartz supergrains multi grain and single grain thermally transferred osl of quartz and post infrared infrared stimulated luminescence of k feldspars assessments of luminescence characteristics and laboratory quality assurance tests indicate that the huescar 1 sediments are well suited for extended range dating applications and the resultant chronologies obtained using different luminescence approaches display a high degree of consistency our combined luminescence ages reveal that the fossil bearing fluvial sediments at this marginal lacustrine site were deposited 420 460 ka or possibly 420 570 ka which is younger than some of the tentative late early to early middle pleistocene ages inferred from faunal associations comparison of the dating results with taphonomic taxonomic and geomorphic evidence suggests that the site may preserve an admixture of bones in primary depositional context and reworked fossils sourced from potentially older deposits in the surrounding valley as such the luminescence ages obtained for the host sediments may not be contemporaneous with all of the faunal remains preserved at huescar 1

comments on an anthropogenic modification in an eremotherium tooth from northeastern brazil over150yearsago peterw lundproposedthatlatequaternaryextinct megafauna henceforth just megafauna and homo sapienscoexisted in brazil lund 1844 but only recently his hypothesiswas supported by direct radiocarbon dating on megafauna bones neves and pilo 2003 hubbe et al 2007 2009 2011 these datesshowed that in some brazilian regions at least some speciessurvived until the beginning of the holocene and became extinctafter the arrival of the rst human groups besides the chronolog ical evidence which indicates that humans and megafauna lived inthe same region at the same time there are also claims that theymayhaveinteractedmoreactivelybasedonthe ndingofsingle orvery few bones or bone fragments associated with human occu pation levels near archeological material or showing marks thatsuggest their usage by humans however based on the meticulousrevision provided by prous 2002 it is possible to rule out most ofthese cases due to theircontroversial nature in fact few of those ifany can be held as solid evidence of this close interaction notconsidering scavengingon bones from a long ago deceased animal prous and fogaca 1999 recently dantas et al in press reported the nding of a singletooth fragment of the ground sloth eremotherium in sergipe state northeastern brazil that according to the authors presentsanthropogenic marks that favor the coexistence of this species andh sapiens however in our opinion their work does not providesolid evidence of an interaction of this nature and therefore theaim of this comment is to discuss the validity of their nding asreliable evidence of megafauna more speci cally eremotherium and humans coexistence in sergipe the coexistence and notablythe close interaction between the former and the later may haveimportant implications to the understanding of the initial humanoccupation of south america hence this kind of nding should notbe taken as granted but rather should be analyzed with rigorouscriteria in the following comments we question the interpretationof the marks seen in the tooth as human made cutmarks based on1 thenatureandlocationofthecutmarksand2 thearchaeologicalandpaleontologicalcontextof the nding furthermore wediscussreasons why the conclusions based on this nding could beseverely distorted dantas et al in press 1 described the marks found on thereported tooth as an effort to build a triangular object based onthe material the location of the marks and the scant informationprovided e g it is notclear if morebones fromeremotheriumwerefound if there are more bones from other species with marks whichother species were found it is hardtoaccept that the marksobserved are the result of human intervention on the tooth themarks are described by dantas et al in press 1 as being humanbecause they have parallel grooved striations narrower anddeeper which follow the curvature of the tooth along apical andlateral borders unfortunately these characteristics are unclear tous in the pictures presented by the authors fig 2f shows onlystriations fig 2g appear to show microwear striations when thescaleofthephoto 0 1mm istakenintoaccount andfig 2hshowsa network of shallow striations that crisscross the surface in everydirection in summary it is not possible to see the diagnosticfeatures in the pictures presented by the authors to justify theirconclusions of an anthropogenic origin for them added to the diagnostic dif culties of the marks in this tooth their occurrence is not in accordance to the standard patternsobserved for food processing in ethnographic and archaeologicalcontexts e g walker 1978 lupo 2002 lyman 2005 martinez 2009 thus diminishing the possibility of butchering marks onthis tooth indeed dantas et al in press never claimed thesemarks were the result of butchering however it is very hard to

insights into holocene megafauna survival and extinction in southeastern brazil from new ams 14 c dates abstract the extinction of late quaternary megafauna in south america has been extensively debated in past decades the majority of the hypotheses explaining this phenomenon argue that the extinction was the result of human activities environmental changes or even synergism between the two although still limited a good chronological framework is imperative to discuss the plausibility of the available hypotheses here we present six new direct ams 14 c radiocarbon dates from the state of sao paulo brazil to further characterize the chronological distribution of extinct fauna in this part of south america the new dates make evident that ground sloths toxodonts and saber toothed cats lived in the region around the pleistocene holocene transition and in agreement with previous studies also suggest an early holocene survival for the ground sloth catonyx cuvieri taken together with local paleoclimatic and archaeological data the new dates do not support hunting or indirect human activities as a major cause for megafauna extinction although more data are required parsimony suggests that climatic changes played a major role in this extinction event

u series dating and taphonomy of quaternary vertebrates from brazilian caves abstract the geochronology and taphonomy of internationally important fossil bearing cave deposits were studied both in the semi arid northern bahia area and the subtropical southeastern lagoa santa area of brazil taphonomic analysis suggests that the processes responsible for bone accumulation in the brazilian caves vary between sites and taphonomic bias can therefore be significant in causing differences in faunal composition in the toca da boa vista caves the presence of single articulated skeletons and the entrance related distribution indicate that random penetration of animals is the main mechanism of fossil accumulation a process that biases the assemblage to smaller species and takes place over extended time periods in nearby toca dos ossos cave transport by runoff in the cave river is predominant and biases the fauna remains to larger more robust bones and species deposition probably also occurred only at times of enhanced runoff giving a more contemporaneous assemblage similar processes were responsible for emplacement of the copious fossil remains in the more humid lagoa santa area where terrigenous fossil deposits are found intercalated by massive speleothem calcite layers in this area runoff under a drier climate probably accounts for the sediment emplacement inside caves in both areas the mode of emplacement implies bias in the fossil record resulting in fossil assemblages that do not mirror surface faunas limiting palaeoenvironmental reconstruction mass spectrometric u series analysis of speleothem calcite overlaying fossil remains gives minimum ages for fossil deposition these ages confirm the previous view that many of the deposits derive from the late glacial but also show that much older material some 350 000 yr is also present the habitat requirements of critical fossil species such as bats and monkeys strongly suggest that they derive from much wetter periods when forest cover was present in the currently semi arid northern bahia area taphonomy exerts a major control on the diversity and mode of emplacement of cave fossil deposits in eastern brazil and thus detailed sedimentological and hydrological studies coupled with a sound geochronological approach are essential in quantifying the relative importance of each taphonomic processes before faunal and palaeoecological interpretations can be attempted

local scale proxy evidence for the presence of closed canopy forest in north western borneo in the late pleistocene bones of strategy i bats from the archaeological record of the great cave of niah sarawak abstract the limits of the distribution of closed canopy forest in southeast asia during the glacial cycles of the pleistocene are the subject of continuing debate in this context this paper reports the results of an analysis of a novel line of evidence as a local scale case study 22 dated assemblages of bat bones that were recovered from the archaeological sequences of the great cave of niah in sarawak malaysian borneo were examined by examination of the morphological characteristics of the distal articulation of the humerus seven families and nine genera were identified five species level attributions could be made these assemblages formed a time series of 14 chronological intervals 48 0 35 ky bp ky bp 103 calibrated years before present 1950 incorporating samples from the high glacial interval 26 18 ky bp and last glacial maximum 23 19 ky bp bones of bat taxa that are adapted to forage in the cluttered environments in the interior of closed canopy forest strategy i bats were employed as proxy evidence for the presence of closed canopy forested habitats in the vicinity bones of strategy i bats principally small hipposideros spp were identified in all examined assemblages and intervals in the time series statistical testing indicated no evidence of differences in the absolute frequency of distal humeri from strategy i bats in the pleistocene samples 48 11 8 ky bp or in the entire time series 48 0 35 ky bp and no significant linear trend was found in the time series to suggest an increase of the bones strategy i bat taxa with the onset of the holocene these findings suggest that closed canopy forest habitats have been a persistent component in the landscape around the great cave of niah since 48 ky bp a taphonomic hypothesis is proposed to explain the dichotomy between the findings of this study and the pollen record of the site

carbonate replacements after sulfate evaporites in the middle miocene of egypt abstract massive zones of diagenetic carbonate which replace sulfate deposits are observed in the middle miocene evaporites in several outcrops along the egyptian coast of the gulf of suez these carbonates display marked similarities of morphology lithofacies and stable isotope composition to diagenetic carbonates described in some portions of messinian gessoso solfifera formation of sicily and in the castiles of the upper permian castile formation of the delaware basin the mechanism of mineral transformation is basically bacterial sulfate reduction because the low 13c values of these carbonates argue for the organic origin of carbon the 18o values fall i to two distinct groupings indicating that the carbonates were crystallized during two different diagenetic stages the early diagenetic stage occurred soon after deposition in pore waters of marine origin and at different levels of evaporation organic matter used by bacteria was produced in situ the late diagenetic stage occurred when the tectonic or halokinetic uplift of the sequence caused flushing of the sediments by groundwaters of the phreatic aquifer and hydrocarbon migration furthermore to explain the very low 18o values of these carbonates it is inferred that locally ambient temperatures reached more than 35 c due to the large quantities of energy released during the bacterial sulfate reduction

missing records and depositional breaks in french late pleistocene cave sediments abstract cave entrance and rock shelter infillings are positioned within the pleistocene chronology for three areas of france northern alps franche comte and perigord despite minor local variations it is possible to identify regional types with a consistent depositional record over long intervals of time the interregional variability relates to the frequency and position of the gaps within the infillings sites in the northern alps have not yielded any artifacts older than the upper paleolithic magdalenian and dated sedimentary sequences do not go back beyond the older dryas more complete sequences in franche comte contain mousterian industries two major gaps occur here one lasting about 50 000 yr during the lower glacial and lower pleniglacial periods and the other lasting some 10 000 yr during the upper pleniglacial the sequences are more complete in the perigord where all major climatic phases have been identified with no significant sedimentary gaps differences in sedimentary records can be explained by variations in regional conditions during the last interglacial glacial cycle and especially by the distance from the maximum advance of ice daring glaciation

vertebrate taphonomy and paleoecology in an upper pleistocene tank deposit of paraiba brazil taphonomic modes evidence of temporal and spatial resolutions and paleoecological patterns of the brazilian intertropical region abstract curimatas paleontological site cps preserved one of the most iconic fossil assemblages of late pleistocene vertebrates of brazil fossils were collected in a tank deposit a singular type of quaternary vertebrate bearing deposit of south america in this work a detailed taphonomic study of the tank assemblage of cps is presented this analysis also provides taphonomic and paleoecological data obtained through the application of common multivariate techniques and provides estimates of time and spatial resolution for tank deposits the results show that although the cps assemblage has experienced an array of taphonomic processes the long distance transport was the main process controlling the taphonomic pathway of the thanatocoenosis during the biostratinomic phase and was responsible for the co occurrence of other processes such as abrasion fragmentation and bioclastic sorting the origin of the taphonomic modes of vertebrates in the tank deposit of cps may have been controlled by three major taphonomic phenomena i a taphonomic bias towards the large bodied size ii long time span of transportation towards the final burial environment and iii some degree of reworking furthermore the analysis of these taphonomic modes supports a previous hypothesis although taphonomic biases affect the origin of tank assemblages paleoecological patterns can be preserved with considerable fidelity the time resolution in tank accumulations is of the order of 10 3 to 104 years and their spatial resolution seems to be from local to regional

a key site for inferring the timing of dispersal of giant deer in sardinia the su fossu de cannas cave sadali italy abstract su fossu de cannas sfc cave is one of several known cavities in the sadali plateau in sardinia italy the evolution of the cave is the result of complex erosional and deposital processes that occurred during the neogene and quaternary a fossiliferous cemented conglomerate containing various deer remains now forms the ceiling of a cavity tunnel the faunal remains belong to a large cervid which show some morphological affinity with large deer that have an endemic sardinian lineage praemegaceros sardous praemegaceros cazioti palaeoecological data based on some peculiar features and the large size of the sfc deer suggest that it is the most primitive megacerine found in sardinia to date and the first representative of the endemic lineage the 450 ka u th age for the flowstone capping the fossiliferous layer defines the end of sedimentation in which sadali deer remains are preserved and the dispersal from the mainland of the ancestor of the endemic sardinian megacerini stratigraphic and micromorphological analyses of the cave deposits allow the reconstruction of the timing of the cave s development throughout the pliocene to the holocene

the dominance of an extant gregarious taxon in an attritional accumulation taphonomy and palaeoecological implications abstract a recurrent aspect of the fossil record is the observation of a disproportionate number of specimens or individuals of a single taxon in some deposits which is stated as dominance commonly the dominance is explained as the result of catastrophic or short term mass death events or are proxies for palaeoecological inferences regarding gregariousness however taphonomic stratigraphic and chronologic analyses of fossiliferous deposits have shown that this is not always true to contribute to the study of dominance in fossil assemblages we describe a probable quaternary skeletal accumulation dominated by the extant gregarious rock dwelling rodent kerodon rupestris recovered from sumidouro do sansao a 65 m deep pitfall cave in northeast brazil and discuss the palaeoecological implications of our findings we provide taxonomic identification taphonomic analyses and chronological assessment besides k rupestris minimum number of individuals mni 35 we recorded three taxonomic groups that are the ground sloth catonyx cuvieri mni 1 the anteater tamandua tetradactyla mni 1 and the cougar puma concolor mni 1 the taphonomic analysis of the k rupestris remains supports the idea that entrapment of individuals was the main process of bone accumulation and that the death of cave inhabitants followed by short transport to the main hall possibly occurred kerodon rupestris remains persisted on the surface of the cave deposit for different time spans and were exposed to fragmentation weathering invertebrate boring and encrustation inside the cave environment direct dating suggests differences in the ages obtained and intermittent deposition of the individuals inside the cave it highlights the influence of taphonomic controls on gregarious taxa such as k rupestris towards dominating attritional time averaged assemblages furthermore it demonstrates that such assemblages do not necessarily support inferences about single event mortality and gregariousness of the dominant taxon

uranium series chronology and environmental applications of speleothems an increasing number of scientists recognize the value of speleothems1 as often extremely well preserved archives of information about past climate vegetation hydrology sea level nuclide migration water rock interaction landscape evolution tectonics and human action well constrained data are required to document past changes reconstruct past patterns and predict future responses of the earth system at a wide range of spatial and temporal scales speleothems are particularly useful in this regard because they can be found in many locations of the globe sampled at high resolution and reliably dated using high precision uranium series techniques speleothems are bodies of mineral material formed in caves as the result of chemical precipitation from groundwater flowing or dripping in a cave most speleothems are composed of calcite formed by slow degassing of co2 from supersaturated groundwater but aragonite and gypsum forms are also common particularly near cave entrances where evaporative effects are important a host of different speleothem types decorate the walls ceilings and floors of caves and their mineralogy and morphology is a function of fluid flow and chemistry of waters feeding a particular location as well as the ambient conditions temperature chemistry light in the air or water filled void subaerial forms include the familiar stalagmites stalactites draperies flowstones subaqueous forms include rimstone pools rafts mammillary calcite wall coatings and dog tooth spar for an extensive review of the types of speleothem that have been observed see hill and forti 1997 speleothems are used in a multitude of ways to explore past environmental conditions perhaps the most fundamental of which is their very presence or absence deposition of speleothems relies on sufficient water supply and soil co2 to enable dissolution and transport of reactants in the vadose zone to underlying caves in arid or glacial times conditions may not have been favorable for speleothem formation

quaternary ecological and geomorphic changes associated with rainfall events in presently semi arid northeastern brazil several geomorphic features and palaeobiotic remains in now semi arid northeastern brazil indicate major palaeoenvironmental changes during past periods of increased rainfall 230th mass spectrometric ages of speleothems and travertines have allowed the determination of the timing and duration of wetter than present conditions the data demonstrate that wet events have occurred throughout much of the pleistocene present dry conditions having been established at the end of the younger dryas a markedly different fauna comprising megafaunal elements not adapted to the present low arboreal scrubland caatinga vegetation existed in the area palaeobotanical remains embedded in travertine indicate forested vegetation at these wetter intervals suggesting that the caatinga was then replaced or mixed with a semi deciduous forest due to the abundance of travertine sites containing fossil botanical remains in northeastern brazil it is believed that forest expansion occurred over large areas of the now semi arid zone showing that the long hypothesised forested links between biodiversity rich amazon and atlantic rainforests may indeed have existed during these moister phases copyright 2004 john wiley sons ltd

mid pleistocene cave fills megafaunal remains and climate change at naracoorte south australia towards a predictive model using u th dating of speleothems abstract the limestone caves of the naracoorte region in south australia contain extensive deposits of megafauna rich sediments and intercalated cave formation speleothems high precision thermal ionisation mass spectrometry tims u th dating of flowstones directly associated with several large deposits reveals a distinct cyclicity in the timing of sediment and flowstone depositional events in the naracoorte caves this pattern parallels a cyclical alternation of wet phases and intervening periods with a water deficit over the last 500 ka ayliffe et al 1998 geology 26 147 dates from flowstone interlayers in the fossil deposits coincide with the massive speleothem growth events which characterise wet phases hiatuses in flowstone deposition correlatable through several cave systems imply that water deficits were initiated by regional aridity during full glacial and then extended into the succeeding warmer wetter interglacials clastic deposits in caverns with restricted entrance shafts correlate with hiatuses suggesting many of these deposits contain fauna representative of full glacial and interglacial climates caverns with small openings have often been sealed from the surface and dating has constrained the length of accumulation episodes in several fossil deposits one to less than 20 ka the hydrological regimes and environmental conditions inferred from the timing of speleothem deposition have been used to develop a model for cyclic sediment and bone accumulation in the caverns at naracoorte over the last 400 ka the giant victoria fossil chamber deposit accumulated prior to 200 ka and because its entrance is large it may contain faunas representative of all climatic phases there has been no apparent change in faunal diversity at naracoorte over at least three glacial interglacial cycles of the middle pleistocene

successful application of uranium series dating of fossil bone abstract a novel approach to uranium series disequilibrium dating is presented and used successfully to date bones from several european archaeological and palaeontological sites a method is described based on a proposed mechanism of uranium uptake and fixation derived from present understanding of the biochemistry of fossilizing bones and the geochemistry of uranium stability of uranium in fossil bone is predicted under particular conditions of local depositional environment and the importance of the inhomogeneous distribution of uranium through bone to uranium series dating is explained sample bones from several different sites have been examined taking into account the three factors of uptake mechanism uranium distribution and sedimentary environment and have yielded ages in good agreement with those derived by alternative dating methods or from chronologically fixed stratigraphical positions

fossil bats from the quaternary of serra da capivara northeast brazil abstract the serra da capivara national park in the southeast of state of piaui is widely recognized for its important archeological sites however in the areas surrounding the park there are also paleontological sites especially limestone caves where fossils of small mammals have been found this material was recovered from deposits attributed to the late pleistocene and early holocene previous works have listed the occurrence of eight species of bats in two caves toca do gordo do garrincho and toca da janela da barra do antoniao the present study reports new data on the chiroptera from serra da capivara based on cranio mandibular fragments from three caves from toca do barrigudo we identified tonatia sp phyllostomus discolor and artibeus planirostris the latter two species have also been identified from toca do serrote do artur in addition to lophostoma sp and eptesicus fuscus from toca do gordo do garrincho the record of desmodus rotundus is confirmed along with the identification of lophostoma sp thus the following taxa are recorded for the first time for the quaternary of the serra da capivara region lophostoma sp phyllostomus discolor and eptesicus fuscus all taxa currently occur in the area except eptesicus fuscus which has previously been recorded for the quaternary of brazil in the states of rio grande do sul and bahia suggesting a much wider geographical distribution at least until the beginning of the holocene which is corroborated by the serra da capivara findings