the taphonomic record of upper siwalik pinjor stage landscapes in the pabbi hills northern pakistan with consideration regarding the preservation of hominin remains abstract the pabbi hills contain a late pliocene and early pleistocene sequence that was extensively surveyed for fossil remains ca 40 000 specimens from an estimated 1000 individual animals were collected from three types of fossil occurrences n 445 twenty fossil accumulations produced ca 50 of all fossils found and over half of all fossil occurrences contained 100 kg adult body size although buried fossils were generally well preserved much information was lost after re exposure by fragmentation and sub aerial weathering comparisons with miocene siwalik faunas and environments indicate considerable loss of habitat diversity fewer types of herbivores increased herbivore body size and an increased role of predators notably pachycrocuta as accumulating agents the absence of hominin remains can be attributed to biases towards the preservation of larger animals the effects of fragmentation and the absence or rarity of stone suitable for making stone tools

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

a large mammal site in a meandering fluvial context fonelas p 1 late pliocene guadix basin spain sedimentological keys for its paleoenvironmental reconstruction abstract the fonelas p 1 large mammal site is located stratigraphically in the youngest unit late pliocene pleistocene of the endorheic fill of the guadix basin betic cordillera at the site location this unit is represented by fluvial sediments of the basin s axial drainage system the general succession of the site consists of stacked fining upward cycles basically beginning with gravel and or sand filling a meandering channel and concluding with floodplain mud and carbonate each of the cycles is made up of four facies associations determined by sedimentological analysis of the sections measured in the paleontological excavation of the site these associations correspond to sedimentation in definite areas of the fluvial system a filling of a sinuous channel at maximum activity b levee deposits c abandoned channel and d floodplain in the cycle in which the site is located there is a fifth association e where the main fossil concentration is found fonelas p 1 this is a facies bioturbated by mammals moving over sediments of the abandoned channel association c by space time reconstruction of the fluvial environments we can infer that the morphological depression caused by a meander abandonment due to chute cut off was used as a hyena den the animal settlement ended when overflow from the laterally migrating active channel began to bury the abandoned meander with floodplain sediments

ichnofossils of the alluvial willwood formation lower eocene bighorn basin northwest wyoming u s a abstract the ichnofossil assemblage of the lower eocene willwood formation consists of at least nine distinct endichnia that are preserved in full relief four forms three ichnogenera and four ichnospecies are new and represent fodinichnia and domichnia of oligochaete worms an insect or spider an unknown vertebrate probably a mammal and domichnia of an unidentified organism other potential trace makers of the ichnofauna include insects mollusks and decapods in contrast to an egyptian oligocene fluvial ichnofauna produced largely by animals that burrowed in stream channel deposits the willwood assemblage is principally of flood plain origin though the ichnofauna occurs in a variety of paleosol types most of the fossils are restricted in distribution to specific sediment and soil types and within paleosols to specific identifiable horizons this attribute will make them valuable indiced of paleoenvironment once they are better known in other ancient alluvial sequences the environment suggested by the willwood trace fossils damp but not wet soils with fluctuating water tables is consistent with the warm temperate to subtropical possibly monsoonal conditions that are interpreted for the willwood formation by independent evidence of body fossils and paleopedology

taphonomy of vertebrate assemblages from the paleogene of northwestern wyoming and the neogene of northern pakistan abstract we compare the taphonomy of vertebrate assemblages from two long continental records the early paleogene of the bighorn basin wyoming and the neogene siwalik sequence of northern pakistan both sequences contain a similar array of fluvial facies and the abundance of these facies differs among formations we document environments of preservation of vertebrate localities over time to determine comparability of fossil assemblages within and between sequences changes in sample size and species richness are noted to reveal potential sampling effects on patterns of faunal turnover preservational history determined the environment sample size quality of specimens taxonomic composition and spatial and temporal resolution of fossil assemblages and thereby the quality of the fossil record and its suitability for further analyses in both sequences changes in prevailing taphonomic processes reflect changes in lithofacies and habitat distribution correlated changes are found in fossil productivity species richness and faunal composition both sequences contain some episodes of apparent faunal change in which appearances and disappearances of rare taxa can be attributed principally to changes in sample size the paleogene record has high taxonomic resolution i e to genus or species for most mammalian fossil remains temporal and spatial averaging of paleogene fossil assemblages changes with lithofacies the neogene record has higher taxonomic resolution for remains of small mammals different preservational circumstances impose different constraints on paleocological and evolutionary analyses the best opportunities for paleocommunity reconstruction are provided by high taxonomic resolution large samples nd varied environments of preservation these circumstances are found in limited portions of each record the best opportunities for documenting evolution within lineages and species replacement patterns are provided by high taxonomic resolution high temporal resolution and consistent preservational context these taphonomic attributes pertain to the more common paleogene mammals particularly from the rich paleosol localities of the willwood formation and to the more common neogene small mammals from abandoned channel fills of the siwalik record

taphonomic and paleoecologic investigations of the late cretaceous santonian iharkut vertebrate assemblage bakony mts northwestern hungary abstract the iharkut vertebrate locality an open pit mine in the bakony mountains western hungary has provided a rich and diverse assemblage of late cretaceous santonian continental vertebrates the isolated and associated remains represent 31 different taxa including fish amphibians turtles lizards pterosaurs crocodilians non avian dinosaurs and birds sedimentologic investigations suggest that the iharkut depositional environment was represented by the floodplain of a very low gradient river the 10 50 cm thick bonebed of site sz 6 is the most important fossiliferous layer in the open pit mine and analysis of this site indicates alternating energy conditions during the bone accumulation which resulted in fossils of different states of preservation being deposited together the vertebrate assemblage of site sz 6 includes three main different subsets with widely different taphonomic history the characteristics and the preservation mode high rate of abrasion and the spherical shape of the bone pebbles suggest that this type of the isolated bones was more exposed to abrasion and probably the remains were transported from farther away than the other isolated bones the second group includes 88 of the iharkut collection containing most of the identified isolated bones and teeth and represents polytypic attritional remains transported and deposited by high density flow during ephemeral flood events meanwhile the monospecific ankylosaur skeletal material from iharkut site sz 6 may represent a mass death assemblage because seven skeletons of hungarosaurus were discovered from an area of approximately 400 m 2 and in many cases close to each other in the same layer the iharkut vertebrate assemblage is dominated by bones of aquatic semi aquatic animals while the number of terrestrial animal remains is subordinate the taphonomic analysis of the ankylosaur material from iharkut locality further strengthens the previously suggested hypothesis that some of the ankylosaurs preferred wetland habitats e g areas along fluvial systems while the other two herbivorous dinosaur groups from iharkut ornithopods and ceratopsians were probably living in distal habitats

sedimentation in an arid zone anastomosing fluvial system cooper s creek central australia abstract cooper s creek is a large ephemeral multi channel fluvial system in the lake eyre basin of arid central australia the large extent and aggradational regime of the system make it a suitable model for interpreting ancient successions formed under similar environmental conditions the dominant channel pattern in the cooper is a combination of relict braids and active anastomosing channels the braids are the partly buried surface expression of a sand sheet attributed to a pluvial episode about 5 000 years ago whereas the anastomosing pattern is interpreted as an adjustment to the present arid climate tectonism and eolian processes are minor localized influences the anastomosing channels accumulate sand but they occupy a small part of the floodplain on which overbank mud is blanketing the relict braids a preliminary depositional model for arid zone anastomosing fluvial systems comprises a mud dominated succession with minor isolated channel sands other features are deep desiccation cracks minor carbonaceous horizons duricrusts and evaporite horizons

taphonomic modes on fluvial deposits of the monte hermoso formation early pliocene buenos aires province argentina abstract the sedimentary deposits of the monte hermoso formation outcropping at its type locality farola monte hermoso buenos aires province argentina accumulated through fluvial processes acting on highly sinuous rivers the monte hermoso formation comprises a rich vertebrate fauna corresponding to the montehermosan stage age early pliocene which includes numerous and diverse vertebrate remains comparative taphonomic analysis indicated that the faunal assemblages coming from two different fossiliferous levels fl 1 and fl 2 recognized in floodplain deposits and channel deposits respectively are composed of remains affected by diverse taphonomic processes and therefore representing distinct taphonomic histories the variations recorded between both fossiliferous levels with respect to their taphonomic attributes and sedimentary context allowed the recognition of two distinct taphonomic modes floodplain in the fl 1 and channel lag in the fl 2 these taphonomic modes represent different conditions within the range of taphonomic histories for the monte hermoso formation assemblage formed by attritional accumulation of remains at the moment continental systems linked to fluvial environments have been poorly analyzed for the south american neogene this study contributes new information on taphonomic and paleoenvironmental characteristics of this type of deposit

the miocene climatic optimum evidence from ectothermic vertebrates of central europe abstract data sets of central european temporal distributions of thermophilic ectothermic vertebrates channidae varanidae chamaeleonidae cordylidae tomistomidae alligatoridae giant turtles and of north alpine foreland basin nafb distributions of ectothermic vertebrates adapted to dryer habitats albanerpeton inexpectatum salamandra sansaniensis bufo cf viridis chamaeleo caroliquarti gekkonidae varanus hofmanni bransateryx sp are analysed two main migration events of thermophilic ectotherms at 20 ma and 18 ma in the lower miocene are discerned they indicate the beginning of the miocene climatic optimum in central europe 42 45 n palaeolatitude with a lower limit of the mean annual temperature mat of 17 4 c derived from the minimal mat of their extant relatives furthermore additional palaeobotanical data and records of bauxite point to a mat of 22 c this warm and humid optimum peaked at 18 16 5 ma ottnangian karpatian and is confirmed by the coexistence of all investigated thermophilic taxa the following period early badenian is characterised by probably unchanged temperatures but a seasonality in precipitation with dry periods up to six months two major seasonal phases between 16 3 and 15 7 ma earliest early badenian and between 14 7 and 14 5 ma early middle badenian transition are indicated by an immigration of dry adapted taxa from the surrounding karst plateau to the nafb it is presumed that the tectonical reorganisation of the central paratethys realm had considerable influence on this regional humidity pattern the warm period ended abruptly between 14 0 and 13 5 ma middle late badenian transition with major regional extinction events of most of the thermophilic groups in central europe and a drop of the mat of probably more than 7 c to temperatures around 14 8 15 7 c this drop can be attributed predominantly to a decrease of more than 11 c of the minimum cold months temperature this temperature decrease marked the beginning of a climatic zonation of the european continent and is also evidenced by a progressively southward disappearance of the crocodile diplocynodon from 38 45 n palaeolatitude to 30 37 n during the middle and earliest late miocene the results correlate well with palaeobotanical data from the mid latitudes of europe and north america and the deep sea temperature curve generated from oxygen isotope ratios

preliminary taphonomic analyses on the mammalian remains from wulanmulun paleolithic site nei mongol china abstract nearly three thousand specimens of mammalian remains were unearthed from wulanmulun paleolithic site in ordos nei mongol during 2010 2012 rescue excavations the majority of the remains belong to medium and large sized hoofed mammals particularly woolly rhinoceros the materials are mostly fragmental and associated with thousands of stone artifacts taphonomic analyses show that the remains were subjected to little alluvial transportation but some weathering before burial only two kinds of bone tools antler hammers and shaft points were identified the cut marks on the bones showed that the animals were mostly hunted and butchered on the spot rather than scavenged the prey were likely lured or driven into the site and trapped in the muddy alluvial deposits and butchered near or after their death the site is more probably a trap for hunting large animals and a follow up butchery shop

an early pennsylvanian waterhole deposit and its fossil biota in a dryland alluvial plain setting joggins nova scotia the terrestrial ecology of pennsylvanian tropical wetlands is understood in detail but coeval dryland ecosystems remain highly enigmatic to fill this gap in our knowledge a pennsylvanian langsettian continental red bed succession was studied at the classic joggins locality nova scotia these units represent the deposits of seasonally dry alluvial plains traversed by anastomosed drainage networks one channel complex informally known as the hebert beds the focus of this study contains an unusual fossil assemblage and is interpreted as an alluvial waterhole deposit that formed following drought induced cessation of channel flow adpressed and charred fossil plant remains indicate that the alluvial plain surrounding the waterhole was covered by fire prone cordaite vegetation with hydrophilic lycopsids and sphenopsids restricted to waterlogged riparian niches gigantic unionoid freshwater bivalves locally in life position and occurring in large numbers in the waterhole were probably infaunal suspension feeders during periods of fluvial activity but aestivated in channel bottom muds when flow ceased abundant terrestrial gastropods found clustered around fossil plant detritus may have been deposit feeders scavenging dry portions of channel floors common partially articulated remains of small to medium sized tetrapods possibly represent animals drawn to the waterhole during drought when surface water was scarce elsewhere in terms of both sedimentology and biology the hebert beds alluvial complex bears a very close similarity to the seasonal drainages and waterholes of present day central and northern australia this unique deposit sheds significant new light on the nature of pennsylvanian dryland tropical ecology

evolution of catskill upper devonian river systems intra and extrabasinal controls abstract the frasnian catskill magnafacies of the catskill region new york state represents alluvium deposited in a foreland basin adjacent to the acadian fold thrust belt facies characteristics vary in space and time in association with a series of transgressive regressive sequences on the order of 102m thick away from the paleoshoreline and upsection the channel belt sandstone bodies within a given regressive sequence show 1 an increase in mean grain size from fine to medium and coarse sand 2 an increase in amount of large scale cross stratification relative to small scale cross stratification and planar stratification 3 a decrease in the inclination of lateral accretion surfaces and more common truncation of their upper parts by chute channel fills 4 an increase in th proportion of sandstone filled channels relative to those filled with sandstone plus mudstone the overbank sandstone mudstone beds concomitantly increase in mean grain size the proportion of channel belt deposits relative to overbank deposits increases slightly with distance from the paleoshoreline and the degree of overlap connectedness of channel belt sandstone bodies increases markedly paleohydraulic analysis shows that channels had low sinuosity less than 1 25 and were predominantly unbraided channels ranged from tens to hundreds of meters wide and were meters in depth channel slopes ranged from approximately 0 0001 to 0 0003 increasing with mean grain size of channel deposits but decreasing as bankfull discharge increased bankfull mean velocity varied little from 0 5 to 0 7 m s with distance from the paleoshoreline channels decreased in sinuosity and increased in sediment size slope and braiding index increase in proportion and connectedness of channel belt deposits with distance from the paleoshoreline probably reflects upvalley increase in channel belt width floodplain width ratio rather than variation in deposition rate avulsion frequency ratio du ing regression and transgression these spatial facies changes are reflected in respectively coarsening upward and fining upward vertical sequences eustasy probably had a minor influence on frasnian regressive transgressive sequences compared to the effects of varying rates of tectonic uplift sediment supply and subsidence there is no evidence of long term climatic change either in the distribution of river channel geometries or in the distribution of paleosols and plant and animal activity on the extensive floodplains

plant and mammal diversity in the paleocene to early eocene of the bighorn basin abstract abundant plant and vertebrate fossils have been recovered from fluvial sediments deposited in the bighorn basin wyoming during the first 13 m y of the tertiary here we outline and discuss changes in the composition and diversity of floras and faunas during this period which includes the recovery of terrestrial ecosystems from the k t boundary extinctions and later during the paleocene eocene transition the greatest global warming of the cenozoic floral diversity has been studied at three levels of spatial resolution sub local at individual collecting sites local along a single bed or stratigraphic horizon and basin wide regional sub local diversity shows a moderate increase from the early to late paleocene followed by a decrease across the paleocene eocene boundary then an increase into the later early eocene local heterogeneity was lower in paleocene backswamp floras although distinct groups of species dominated in different local fluvial settings such as backswamps and alluvial ridges heterogeneity of backswamp forests increased by about 65 from the early to late wasatchian early eocene the number of plant species inferred from the bighorn basin dataset rose gradually from the puercan to an early clarkforkian peak of about 40 species declined sharply to about 25 species by the clarkforkian wasatchian boundary then rose through the wasatchian to about 50 species a regional analysis of mammalian genera shows high turnover and a rapidly increasing number of genera within a million years of the k t boundary 10 50 genera a slight decline to 40 genera by the early clarkforkian then an increase from 40 to 75 genera by the late wasatchian our analyses found no major extinctions in mammals during the paleocene and early eocene in the bighorn basin but a one third decrease in the number of plant species at about the paleocene eocene boundary rates of taxonomic turnover were much higher for mammals than plants the diversity trends for plants and mammals show little congruence implying that the two groups responded in a very different manner to post k t extinction opportunities there is also little congruence between plant diversity levels and change in mean annual temperature mat as inferred from foliar physiognomy

facies architecture and palaeoenvironmental implications of the upper cretaceous santonian csehbanya formation at the iharkut vertebrate locality bakony mountains northwestern hungary abstract the csehbanya formation santonian exposed in the iharkut open pit bakony mountains hungary is made up of a cyclic alternation of conglomerate sandstone and variegated siltstone and clay deposited in a fluviolacustrine environment as a result of continuous excavation since 2002 it has yielded rich and diverse continental vertebrate and plant assemblages a facies and architectural analysis of the csehbanya formation at this location identified four main lithofacies associations with eight subtypes consisting of 1 lenticular sandstones representing river channels 2 conglomerates with sandstone coarse grained likewise representing channel deposits 3 heterolithic channel fill high density flash flow deposits 4 splay sandstones produced by crevasse splays 5 dark sandy siltstone small scale stagnant pool deposits with high organic content 6 greenish grey claystone deposits of shallow lakes and ponds 7 reddish moderately drained paleosols and 8 yellowish mottled hydromorphic paleosols the sedimentological investigations revealed that the terrestrial deposits exposed by the iharkut open pit were formed in an anastomosing fluvial system because i the alluvial architecture is characterized by large proportion of overbank deposits encasing the channel sandstone bodies ii the ribbon shaped sandstone bodies are dominant iii cross bedding and lateral accretion are almost completely absent in the channel fill deposits and iv the sandstone bodies are clearly isolated from each other embedded in floodplain sediments suggesting multiple co existing channels the most important vertebrate fossil site sz 6 was examined in special detail because it shows peculiar lithological features the layers richest in fossils unit 1 of sz 6 site are interpreted as a lag deposit formed during an episodic high density flash flood event representing a relatively short time interval i e probably within a single rainy season

terrasses de la riera dels canyars gava barcelona the landscape of heinrich stadial 4 north of the ebro frontier and implications for modern human dispersal into iberia abstract terrasses de la riera dels canyars is an upper pleistocene fluvial deposit containing the remains of large mammals principally accumulated in the framework of hyena denning in the area as well as a few artifacts radiocarbon dated to 39 6 ka cal bp the time of heinrich stadial hs 4 this site enables us to reconstruct the environmental conditions then prevalent in the ne of the iberian peninsula the concentration in a single locus of finds generated by different agents relates to a flash flood event the rapidity of which combined with the absence of archaeological ecological or paleontological incongruities in the composition of the assemblage warrants an assumption of broad contemporaneity for its contents the ecofactual evidence fauna pollen charcoal phytoliths indicates a steppe dominated environment for the coastal areas between the pyrenees and the ebro delta the dominant elements are cold and dry adapted species but a mediterranean component is present implying a less rigorous climate than farther north in europe the artifacts are clearly upper paleolithic and assignment to the modern human associated aurignacian technocomplex is supported by the radiocarbon dates and the typology of a bilaterally retouched blade this evidence is consistent with the notion that anatomical modernity spread across europe over open landscape niches available pollen data from deep sea cores indicate that during some of the interstadials of marine isotope stage mis 3 a significant vegetation gradient existed at 40 n broadly coincident with the ebro frontier temperate and warm temperate trees expanded significantly to the south while steppe tundra landscapes remained dominant to the north a contrast best seen during greenland interstadial gi 8 such an environmental boundary must have implied a durable barrier to diffusion and migration during interstadials under the cold and arid conditions of hs4 the site of canyars shows that the eurasian steppe tundra extended as far south as the llobregat delta however the environmental reconstructions available for the lower ebro valley and adjacent mountains of the iberian range farther south suggest that they formed at this time a belt of semi desert or steppe desert landscapes thus maintaining the boundary effect despite the climatic reversal the persistence of such a boundary through hs4 and the interstadials that bracket it must have played a role in the delayed arrival of the aurignacian and modern humans to southern and western iberia which continued to be settled by middle paleolithic neanderthals well beyond 40 ka cal bp

fluvial transport of bovid long bones fragmented by the feeding activities of hominins and carnivores this study explores the hydraulic transportability of bovid long bone fragments created through hominin and carnivore carcass consumption in order to determine the effect of fluvial transport on the incidences of hominin and carnivore induced bone surface modifications transportability was determined using an oval race track flume and 311 long bone fragments from modern control collections of hominin and carnivore modified bone results show that the fluvial transport of long bone fragments is predicted by animal size class and bone specimen size as measured by maximum cortical thickness maximum length and maximum width all of these variables can be measured on fossil specimens long bone portion midshaft near epiphysis and epiphysis does not affect transport and hydraulic transport does not substantially modify the incidences of tooth percussion and cut marking in transported or lag assemblages in low energy fluvial environments implications of this study are 1 animal size classes and cortical thickness length and width of long bone fragments can be used to identify fluvial winnowing in fossil assemblages 2 analyses concerning the relative timing of hominin and carnivore carcass consumption based on the proportions of long bone fragments bearing tooth percussion or cut marks can be meaningfully applied to fossil assemblages deposited in low energy fluvial environments

isochronous fluvial systems in miocene deposits of northern pakistan a palacomagnetic isochron dated at about 8 1 myr bp and detailed lithostratigraph of a 40 m interval exposed along strike for 40 km establish the depositional patterns of two contemporaneous interfingering fluvial systems in the upper part of the meddle siwalik sequence the two systems referred to as the buff and blue grey differ in unit shape lithofacies bedding sequence palaeocurrent direction and sand composition interfingering occurs along the south west north east strike of the outcrops with the palaeodrainage directions of the two systems generally perpendicular to this line the axis of the blue grey system which deposited widespread sheet sands and silts lay toward the south west end of the study area the more complex axis of the buff system which deposited shoe string sand bodies and lage volumes of silt and clay lay toward the north east the source area for both systems was the rising himalyan belt to the north and noth east of the study area at maximum extent the blue grey system occupied a channel belt at least 25 km wide channel belt widths and depths for the buff system are 1 3 km and 3 7 m respectively current directions averge 94 for blue grey sands and 136 for buff sands blur grey sands contain 20 more rock fragments and are otherwise less mature than buff sands the buff system shows a verticla pattern of avulsion palaeosol formation and floodplain aggradation which we attribute to autocyclic processes of parallel rivers the blue grey system shows phases of erosion accompaniced laterally by plaeosol formation folowed by valley fill and overfowing of interfluve surfaces theis pattern may be caused by allocyclic presses affecting the source area we interpret the blue grey system as a major drainage from the interior himalayas perhaps the ancestral indus and the buff system as a complex of smaller drinages along the mountain front which were probably ributaries to the bluegrey syste vertebrate fossils including hominoid primates from the area are almost exclusively associated with lithofacies of the buff system and this probably refects both taphonomic and palaeoecological differences between the two systems

interaction of an antecedent fluvial system with early normal fault growth implications for syn rift stratigraphy western corinth rift greece continental overfilled conditions during rift initiation are conventionally explained as due to low creation of accommodation compared with sediment supply alternatively sediment supply can be relatively high from the onset of rifting due to an antecedent drainage system the alluvial lower group of the western plio pleistocene corinth rift is used to investigate the interac tion of fluvial sedimentation with early rifting this rift was obliquely super imposed on the hellenide mountain belt from which it inherited a significant palaeorelief detailed sedimentary logging and mapping of the well exposed syn rift succession document the facies distributions palaeocurrents and stratigraphic architecture magnetostratigraphy and bios tratigraphy are used to date and correlate the alluvial succession across and between fault blocks from 3 2 to 1 8 ma a transverse low sinuosity braided river system flowed north north east to east across east west striking active fault blocks 4 to 7 km in width deposits evolved downstream from coarse alluvial conglomerates to fine grained lacustrine deposits over 15 to 30 km the length scale of facies belts is much greater than and thus not directly controlled by the width of the fault blocks at its termination the distribu tive river system built small stacked deltas into a shallow lake margin the presence of a major antecedent drainage system is supported by i a single major sediment entry point ii persistence of a main channel belt axis iii downstream fining at the scale of the rift basin the zones of maximum sub sidence on individual faults are aligned with the persistent fluvial axis sug gesting that sediment supply influenced normal fault growth instead of low accommodation rate during the early rift phase this study proposes that facies progradation can be controlled by continuous and high sediment sup ply from antecedent rivers

taphonomy of the late cretaceous dinosaur bearing beds of the lano quarry iberian peninsula abstract the lano quarry located in the northern part of the iberian peninsula basque cantabrian region has yielded a diverse continental vertebrate assemblage from the late cretaceous late campanian to early maastrichtian the fossil assemblage consists of almost 40 species including bony fish amphibians lizards snakes turtles crocodilians dinosaurs pterosaurs and mammals lano is the most productive european vertebrate locality hitherto known from the late cretaceous the sedimentology of the lano section shows that the three associated fossiliferous beds known as l1a l1b and l2 were deposited in an alluvial system composed primarily of fluvial sands and silts the sedimentary structures are consistent with channel areas within an extensive braided river the l1a level was excavated in detail and mapped following a square metre grid system the main features of the multispecies vertebrate assemblage are as follows wide range of body size including microfossils large proportion of adult individuals rare articulated skeletal parts size sorting and dominance of small elements high spatial density long bones showing some preferential orientation variable dip variable degree of breakage and large proportion of splintering wide range of weathering and abrasion no evidence of predatory activity or chemical alteration on the basis of these features we suggest that the lano association lies between the taphonomic modes for attritional vertebrate assemblages in fluvial channels though it tends more toward the channel fill than the channel lag mode the l1a sample of lano is a heterogeneous assemblage of elements ranging from isolated bones and teeth to articulated skeletons with allochthonous and para autochthonous characteristics it consists of a mixture of vertebrates from different palaeocommunities and includes aquatic or semi aquatic elements and remains transported from a variety of habitats on the alluvial plain the dinosaur bones are commonly broken and show a greater degree of abrasion than those of freshwater vertebrates indicating that they may be allochthonous however actinopterygians amphibians pleurodiran turtles and eusuchian crocodilians are interpreted as being para autochthonous palaeobatrachid frogs bothremydid turtles and alligatoroid crocodilians are the most relatively abundant vertebrates of the lano fossil assemblage the occurrence of pelomedusid turtles and crocodilians is indicative of an intertropical warm climate

experiments in taphonomy abstract several long term taphonomic experiments are described with the aim of providing comparative data with which to interpret palaeontological and archaeological sites the study of taphonomy is an adjunct to site interpretation especially the reconstruction of palaeoecology and an understanding of taphonomic processes can only come about through actualistic and laboratory analyses experiments described include the overton down earthworks 32 year old buried bone trampled bone from draycott 17 years old weathered amphibian bone also from draycott 16 years old surface weathered bone from arabia following 10 years exposure bone dispersal weathering burial burning and scavenging in rhulen wales with many skeletons ranging from 1 to 20 years old and finally a series of laboratory experiments set up to test particular processes these included earthworm activity abrasion breakage and predation on small mammals two examples are given at the end to show how the effects of these processes can be identified in the past and how their identification can help to resolve particular issues in two palaeontological sites these are the middle pleistocene deposits at westbury sub mendip somerset and middle miocene deposits at pasalar turkey

evidence of early c 4 grasses habitat heterogeneity and faunal response during the miocene climatic optimum in the mojave region abstract major changes to landscapes climate and mammalian faunas occurred at the regional scale in western north america during the miocene climatic optimum mco between 17 and 14 ma but few studies have looked at how the mco affected basin scale environments paleoenvironmental reconstructions coupled with mammalian fossil assemblages from the crowder and cajon valley formations in the mojave desert california contribute insights into local scale 10s of kilometers responses to warming during the hemingfordian and barstovian north american land mammal ages by integrating lithological descriptions phytolith analyses carbon isotope composition of preserved soil organic matter 13csom and elemental geochemistry of paleosols we provide reconstructions of depositional environments vegetation and precipitation through the mco phytolith and 13csom evidence suggest that paleoenvironments were predominately c3 grasslands with the earliest potential presence of c4 grasses in the region found within the crowder formation at 17 ma based on elemental geochemistry of paleosols mean annual precipitation estimates are 807 182 mm yr 1 at 17 ma in the crowder formation and 740 800 182 mm yr 1 from 16 to 15 ma in the cajon valley formation our multiproxy approach indicates that the crowder and cajon valley basins were stable large scale braided stream and floodplain systems with intermittent paleosol development and heterogeneity in vegetation and moisture conditions across spatial scales overall we find a signal of local paleoenvironmental stability during the mco however a significant drying trend in the crowder formation does correspond with faunal turnover and reduction in the number of taxa present high species diversity within faunal assemblages especially among small mammals and fewer shared species between the crowder and cajon valley assemblages than expected based on bootstrap analysis indicate that peak mammal diversity was accommodated at both local and regional scales during sustained tectonic activity and the mco in western north america

ongoing research at the late middle pleistocene site of la polledrara di cecanibbio central italy with emphasis on human elephant relationships abstract the site of la polledrara di cecanibbio latium italy is related to deposits of the pg6 sequence middle pleistocene aurelia formation mis 10 and 9 the sediments are mainly volcaniclastic in composition and constitute the filling of incised valleys mainly characterized by fluvial deposits at the base passing upward to fluvio lacustrine and palustrine deposits containing abundant fossil mammal remains and artifacts the arrangement of the specimens and taphonomic observations suggest that most of the transport of the bones occurred during flooding events followed by progressive swampy phases resulting in the formation of areas with stagnant and muddy waters where some elephants became trapped as indicated by remains in partial anatomical articulation recent excavations carried out at the site permit a better definition of the palaeoenvironmental reconstruction already partially outlined in previous publications in particular an area showing a close correlation between the skeleton of an elephant and human activity allows documentation and better understanding of some aspects of human elephant interaction probably mainly represented by scavenging activity

evolution of miocene fluvial environments eastern potwar plateau northern pakistan the miocene pliocene siwalik group records changing fluvial environments in the himalayan foreland basin the nagri and dhok pathan formations of this group in the eastern potwar plateau northern pakistan comprise relatively thick tens of metres sandstone bodies and mudstones that contain thinner sandstone bodies metres thick and palaeosols thick sandstone bodies extend for kilometres normal to palaeoflow and are composed of large scale stratasets storeys stacked laterally and vertically adjacent to each other sandstone bodies represent single or superimposed braided channel belts and large scale stratasets represent channel bars and fills channel belts had widths of km bankfull discharges on the order of 103 cumecs and braiding parameter up to about 3 individual channel segments had bankfull widths maximum depths and slopes on the order of 102 m 101 m and 10 4 respectively and sinuosities around 1 1 these rivers are comparable to many of those flowing over the megafans of the modern indo gangetic basin and a similar depositional setting is likely thin sandstone bodies within mudstone sequences extend laterally for on the order of 102 m and have lobe wedge sheet and channel form geometries they represent crevasse splays levees and floodplain channels mudstones are relatively bioturbated disrupted and represent mainly floodbasin and lacustrine deposition mudstones and sandstones are extremely disrupted in places showing evidence of prolonged pedogenesis these mature palaeosols are m thick and extend laterally for km lateral and vertical variations in the nature of their horizons apparently depend mainly on deposition rate the 500 m thick nagri formation has a greater proportion and thicker sandstone bodies than the overlying 700 m thick dhok pathan formation the thick sandstone bodies and their large scale stratasets thicken and coarsen through the nagri formation then thin and fine at the base of the dhok pathan formation compacted deposition rates increase with sandstone proportion 0 53 mm year for nagri 0 24 mm year for dhok pathan and palaeosols are not as well developed where deposition rates are high within both formations there are 100 m scale variations representing on the order of 105 years in the proportion and thickness of thick sandstone bodies and tens of m scale alternations of thick sandstone bodies and mudstone sandstone strata that represent on the order of 104 years formation scale stratal variations extend across the potwar plateau for at least 100 km although they may be diachronous however 100 m and smaller scale variations can only be traced laterally for up to tens of km alluvial architecture models indicate that increases in the proportion and thickness of thick sandstone bodies can be explained by increasing channel belt sizes mainly average deposition rate and avulsion frequency on a megafan comparable in size to modern examples 100 m scale variations in thick sandstone body proportion and thickness could result from regional shifts in the position of major channels possibly associated with fan lobes on a single megafan or with separate megafans however such variations could also be related to local changes in subsidence rate or changes in sediment supply to the megafan system formation scale and 100 m scale stratal variations are probably associated with interelated changes in tectonic uplift sediment supply and basin subsidence increased rates of hinterland uplift sediment supply and basin subsidence recorded by the nagri formation may have resulted in diversion of a relatively large river to the area alternatively changing river sizes and sediment supply rates may be related to climate changes affecting the hinterland possibly linked to tectonic uplift climate during deposition of the siwalik group was monsoonal although the deposits contain no direct evidence for climate change independent evidence indicates global cooling throughout the miocene and the possibility of glacial periods e g around 10 8 ma corresponding to base of nagri formation if the higher himalayas were periodically glaciated a mechanism would exist for varying sediment supply to megafans on time scales of 104 105 years although eustatic sea level changes are related to global climatic change they are not directly related to siwalik stratigraphic changes because the shoreline was many 100 km away during the miocene

the cave of the monk ban fa suai chiang dao wildlife sanctuary northern thailand biostratigraphic and paleoecological analyses of southeast asian pleistocene faunal sites are based on the assumption that paleontological assemblages are homogeneous this means that the sites formed during a time range shorter than biological evolution range and above all without faunal replacement induced by environmental successions detailed study of the cave of the monk paleontological site in thailand has lead to the conclusion that the complex pattern of this southeast asian paleontological site cannot support such an assumption the cave of the monk provides an ailuropoda stegodon assemblage typical of southeast asia pleistocene fauna the pluridisciplinary study presented here includes i site morphology description ii sedimentological analysis of fossiliferous deposits iii taphonomy study of the bone assemblage and iv electron spin resonance esr dating of tooth samples this integrated approach demonstrates the existence of a pleistocene porcupine den inhabited during mis 3 and 2 the features of this site are commonly reported for other paleontological sites of the area indicating that this kind of site formation is a very general one in southeast asia esr dating and porcupine ethological reports are used to question the site time averaging a time range of a few tens of thousands of years is suggested the paleoecological value of the site can then be discussed on one hand the assemblage is thought to be a valuable paleoenvironmental record considering that the bone accumulation agent is reputed to represent the fauna present in the environment without bias on the other hand the time averaging of the site indicates that site formation range likely covered the environmental fluctuations of the last climatic cycle this last hypothesis is confirmed by the alternating association of species indicated by the stratigraphic distribution of the faunal remains the research demonstrates the need for integrated and pluridisciplinary taphonomic study of southeast asian paleontological sites it also reveals the utility of a microstratigraphic analysis of a fossiliferous karst deposit in order to disentangle the succession of pleistocene mammals in response to environmental changes

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

taphonomy of a late cretaceous mammal bearing microvertebrate assemblage from the deccan inter trappean beds of naskal peninsular india abstract taphonomic analysis of a microvertebrate assemblage from the late cretaceous deccan inter trappean sequence of naskal peninsular india is undertaken to infer the taphonomic factors involved in the accumulation of bones at a time predaceous avians and large mammals were non existent approximately 1 ton of matrix was screen washed and a large number 9100 of isolated skeletal remains of fish amphibians turtles lizards snakes crocodiles mammals and dinosaurs in addition to pelecypods ostracodes gastropods and charophytes were recovered different mechanisms are postulated for the initial accumulation of the fauna whereas scavenging activity played no significant role in the accumulations hydraulic sorting was responsible for accumulation of the terrestrial and semi aquatic component of the fauna the wide distribution of bone fragments presence of pre burial fractures on some of the bones and the occurrence of the assemblage in a thin calcareous palaeosol unit indicate that the vertebrate remains accumulated rapidly as a consequence of a prolonged drought induced mass mortality event and were subjected to subaerial exposure the study concludes that the naskal assemblage accumulated in a distal floodplain lake which served as a natural death trap on whose banks terrestrial and other animals might have gathered in search of food and water during a prolonged drought and perished subsequently due to the desiccation of the lake

preservation of exceptional vertebrate assemblages in middle permian fluviolacustrine mudstones of kotel nich russia stratigraphy sedimentology and taphonomy the kotel nich locality in european russia has long been a rich source of high quality tetrapod fossils including pareiasaurs dicynodonts gorgonopsians and theriodonts the age of the kotel nich locality has been debated but it corresponds to early severodvinian in the russian stratigraphic scheme equivalent to the late capitanian late middle permian on the international time scale remarkably the majority of specimens are complete quite unlike those from most russian permo triassic red bed localities commonest of all are 1 2 metre long pareiasaur skeletons of the genus deltavjatia preserved in hollows on top of a consolidated palaeosol horizon previous taphonomic scenarios in the russian literature have included suggestions that the animals were overwhelmed beneath sand dunes mired in soft fluviatile sediments caught at the bottom of a deep lake trapped in burrows or dumped in fluviatile scours it is probable that the pareiasaurs were searching for water in a time of catastrophic aridification and died weakened in shallow hollows in this case we also emphasise the importance of floodplain microtopography in creating the sedimentary conditions necessary for the preservation of exceptional vertebrate assemblages in a slowly aggrading fluviolacustrine setting

geology and taphonomy of the l espinau dinosaur bonebed a singular lagoonal site from the maastrichtian of south central pyrenees abstract the l espinau site is a dinosaur bonebed from the upper cretaceous of the south central pyrenees north eastern spain that have provided hundreds of bone remains attributed to hadrosauroids together with a rich assemblage of herpetofauna fish and microflora magnetostratigraphy calibrated the site with the early late maastrichtian and the combined sedimentology stable isotope geochemistry and palaeoecology revealed that this fossil site formed in a lagoon in which a mixed freshwater brackish palaeoenvironment was developed this setting displays a south north charophyte zonation from freshwater clavator brachycerus dominated assemblage to brackish or eurihaline conditions feistiella malladae dominated assemblage revealing a palaeoenvironment change towards the coast sedimentology and taphonomy bidirectional arrangement of long bones abrasion and disarticulation indicate that the l espinau site is the result of a cohesive mass flow event originated very close to the sea this process entrained and mixed fauna from both the terrestrial and the brackish marine environment of a lagoon an increasing of the water runoff e g by intense rainfall reworking poorly consolidated sediments is considered here as the most probable triggering mechanism mass flow hosted bonebeds are commonly linked to fluvial palaeoenvironments so our study case is a rare example of bones accumulating near the sea this study adds evidence that hadrosauroids inhabited littoral environments during the maastrichtian in the southern pyrenean area

vertebrate preservation in fluvial channels abstract two taphonomic modes for attritional vertebrate assemblages in channels are proposed based on the sedimentary context of the vertebrate remains and taphonomic features of the bones themselves the channel lag mode includes bones that are buried with coarse lithologies near the bases of active channels the channel fill mode occurs in fine grained to mixed fills of abandoned channels the extreme for a channel lag assemblage would be a cluster of allochthonous abraded unidentifiable fragments and the extreme for a channel fill assemblage would be a cluster of autochthonous unbraded complete skeletons between these extremes there is a broad spectrum of possible taphonomic histories for bones in channels but distinct channel lag vs channel fill modes can be recognized in fluvial deposits in different tectonic and climatic settings throughout the phanerozoic physical and biological processes that affect the different modes produce different samples of vertebrate paleocommunities with bones in the channel lag mode representing transported remains from a variety of habitats whereas channel fill assemblages are more autochthonous and habitat specific channel facies channel pattern and alluvial architecture are used to develop hypotheses concerning how the taphonomic modes relate to different scales of fluvial processes fluvial systems with numerous abandoned channels provide more sites for preservation of relatively complete fossil vertebrates in channel fills while systems that continually rework sediments by lateral migration preserve more vertebrate remains as channel lags large scale physical controls on channel pattern and fluvial architecture probably have had significant effects on the quality and quantity of the vertebrate record throughout the history of land vertebrates taphonomic modes provide a basis for comparing faunas with similar preservational histories throughout the geologic record and they can help to minimize biases in important paleobiological parameters such as diversity estimates and the timing of appearance and extinction events

anastomosing river deposits sedimentation rates and basin subsidence magdalena river northwestern colombia south america situated in a tectonically active foreland basin the magdalena river consists of vertically accreting levee confined channels and adjacent extensive wetlands which are interpreted as an anastomosing river sedimentary system equivalent rates of basin filling and subsidence average 3 8 mm yr 1 based on 18 14c dates from five bore holes drilled to depths of 55 m and sediment transport budgets from 35 years of measurement located in a savanna tropical climate anastomosing river deposits of the magdalena are remarkably similar to the anastomosing deposits of the upper columbia river in a temperate cold climate in western canada suggesting that climate is not a controlling factor of anastomosis the geometry of anastomosing channel fills in the magdalena consists of stratigraphically non uniform low sinuous narrow stringers of sand up to 30 m thick by 600 m wide a width depth ratio of 20 thin 1 2 m off channel crevasse splay sand sheets extend laterally up to 10 km distance when buried both sand deposits become encased by lacustrine or marsh mud to form stratigraphic traps while there are few modern anastomosing river systems as compared to braiding and meandering there may be a disproportionately large number of ancient anastomosed fluvial rock sequences due to the rapid rate of vertical accretion such a different depositional style and geometry of sand bodies have considerable significance in the interpretation of some ancient fluvial rock sequences because it provides an alternative to the meandered and braided river deposition models

early permian depositional environments and pond bonebeds in central archer county texas abstract the lower permian redbeds of north texas contain the oldest abundant non aquatic vertebrate fauna in the past collecting of fossils and study of their paleozoology has been emphasized with the exception of the pioneering work of olson 1958 1977 little attention was paid to sedimentological paleoecological and taphonomical aspects of the fauna this study focuses on the sedimentary framework paleoenvironment fossil content and taphonomy of the most common type of fossil occurrence the pond bonebed five sedimentary facies are recognized meanderbelt sandstones large straigt channel fill sandstones small straight channel fill sandstone interbedded facies and floodplain mudstone these are the components of small meandering river systems with local tributaries and crevasse splays pond bonebeds occur as gray claystone lenses in red floodplain mudstones deposited in oxbow lakes or swamps the fauna is largely aquatic orthacanthus ectosteorhachis paleoniscoids sagenodus or semiaquatic eryops trimerorachis archeria edaphosaurus with subordinate terrestrial elements diadectes dimetrodon fossil plants found as impressions petrifactions and charcoal are indicative of swamps psaronius and well drained soils conifers all of the organic debris accumulated gradually by biological and physical processes occasional isolated but complete vertebrate skeletons are found in the floodplain mudstones

taphonomy of the lamy amphibian quarry a late triassic bonebed in new mexico u s a located in santa fe county new mexico usa the lamy amphibian quarry is a late triassic adamanian bonebed stratigraphically low in the garita creek formation of the chinle group well known for its mass accumulation of metoposaurid amphibians it was initially interpreted as a drought induced death assemblage based on microstratigraphic and sedimentological studies additional and extensive collecting at the quarry and a revised understanding of the bonebed we provide a detailed taphonomic analysis of the lamy amphibian quarry that identifies it as a low diversity multitaxic and monodominant bonebed in pedogenically modified floodplain mudstone the lamy bonebed shows no evidence of drought and is characterized by a high density of completely dissociated bones that show clear alignment by current and sorting enrichment of voorhies group ii and iii elements the bones show no significant abrasion or weathering stage 0 preserve virtually no evidence of scavenging and show no evidence of trampling based on skull lengths the metoposaurid assemblage has a type i survivorship curve and lacks juveniles we thus posit that the following sequence of events formed the lamy amphibian bonebed 1 aggregation cause unknown of a large number of metoposaurid amphibians at a site different from the location of the bonebed though not distant 2 catastrophic mass mortality 3 complete disarticulation and disassociation of the skeletons and 4 rapid transport of the disarticulated bones onto a floodplain surface that was undergoing pedogenesis the lamy amphibian bonebed is representative of the late triassic metoposaurid bonebeds from morocco and the western usa which are monodominant and nearly monotaxic they indicate that aggregation probably of breeding populations and mass death of metoposaurids were relatively common across the riverine floodplains of late triassic pangea

gombore ii melka kunture ethiopia a new approach to formation processes and spatial patterns of an early pleistocene acheulean site abstract to assess the integrity of pleistocene archaeological sites is crucial in the analysis of human behaviour most of the early palaeolithic sites are in active fluvial environments where it is necessary to understand the degree of sedimentary disturbance the analysis of the formation processes through geoarchaeological and geostatistical techniques offers new tools to evaluate if the archaeological assemblage is in autochthonous or allochthonous position gombore ii 850 ka within the archaeological and paleontological complex of melka kunture ethiopia extends over estimated 1000 m2 and yielded a large number of acheulean artefacts fossil mammal bones and two fossil hominin remains the geomorphological setting and deposition patterns of high energy sedimentation in a fluvial channelized environment are similar to those of many other early palaeolithic african sites this is traditionally described as producing a disturbed record with the fortuitous association of faunal remains and lithic industry driven by fluvial processes to assess this hypothesis we analyse here the formation processes and the spatial patterning of the remains we apply geoarchaeological orientation and fabric and spatial tests density grouping k means to the mapped archaeological surfaces and to a present day fluvial surface we observe substantial differences in geoarchaeological features and spatial patterning between the archaeological record lithic materials and faunal remains and the natural clasts of both the archaeological deposit and the bed of the present day river this suggests different depositional processes or temporal events we conclude that the remains produced by the hominins did not haphazardly accumulate after extensive erosion and re sedimentation they rather preserve a reasonable degree of taphonomic and spatial integrity and are possibly representative of different activities

paleoenvironmental controls on vertebrate bearing abandoned channels in the upper carboniferous abstract a paleoenvironmental study of the vertebrate bearing sapropelic coal that underlies the upper freeport coal westphalian d upper carboniferous at linton ohio identifies a hierarchy of physical and chemical controls that influenced the formation of this deposit surface and subsurface data from previous work and field study of extensive exposures show that the fossiliferous cannel occurs at the bottom of an approximately 15 m deep abandoned river meander within a sandstone dominated multistorey sediment body storeys of this sediment body fine upward and consist of varying proportions of sandstones and siltstones within lateral accretion beds that are interpreted as point bar deposits associated channel fills are generally organic rich and composed of coals such as the linton cannel or carbonaceous mudstones maximum observed channel depth is approximately 18 m and the maximum thickness of the multistorey sediment body reaches nearly 40 m the sandstone dominated sediment body that contains the linton cannel trends northwestwardly and contrasts with mudstone dominated coarsening upward sequences that were deposited contemporaneously in adjoining areas this lithic pattern suggests that fluvial activity was restricted to a persistent topographic low that may have resulted from movement along the transylvania fault zone a previously documented basement controlled feature rapid subsidence on the southern side of this structure confined the fluvial system and favored the preservation of deposits within the meander belt including the fossil bearing sapropelic channel fill at linton the low inorganic content and oxbow like outline of the linton fossil deposit and its lateral relationship to other storeys in the multistorey channel sequence indicate that the abandoned meander was closed rapidly by neck cutoff and in the absence of clastic influx filled by sapropelic peat remains of aquatic to terrestrial animals that lived in or near the oxbow lake slowly rotted in this scavenger free anaerobic setting because of the substantial depth of the original meander and a lack of coarse grained fill materials a prolonged period of sapropelic filling insured the preservation of an abundant and diverse autochthonous vertebrate assemblage most westphalian tetrapod deposits represent sapropelic peats and muds and share some of the taphonomic attributes of the linton deposit the high degree of autochthony evidenced by westphalian vertebrate accumulations indicates that taphonomic controls of low lying peat forming alluvial and delta plain systems differ significantly from those of well drained alluvial valley settings

vertebrate paleoecology of the chinle formation late triassic of the southwestern united states abstract the late triassic chinle formation is an extensive series of fluvial and lacustrine sediments exposed mostly in the colorado plateau region fossil vertebrates occur in local concentrations throughout the vertical and horizontal extent of the formation although the most diverse accumulations occur within the petrified forest member in arizona and new mexico successive faunas are known from the lower and upper units of the petrified forest member and can be subdivided into terrestrial and aquatic communities faunal turnover occurs among herbivores phytosaurs and metoposaurs between the lower and upper units no major change is observed in fish faunas throughout chinle deposition mass accumulations of vertebrate fossils in the chinle occurred on floodplains in bogs and small ponds and in or near fluvial channels paleontological and sedimentological evidence supports the interpretation of chinle paleoclimates as having significant precipitation but being strongly seasonal vertebrate occurrences do not clearly reflect the gradual aridification at the end of chinle deposition suggested by sedimentological study

taphonomy of debris flow hosted dinosaur bonebeds at dalton wells utah lower cretaceous cedar mountain formation usa abstract a taphonomic study of the lower cretaceous dalton wells dw dinosaur bonebeds near moab utah provides insight into the origins preservational biases and paleobiological significance of one of the richest and most diverse early cretaceous dinosaur sites known the bonebeds occur in a stacked succession of debris flows at the base of the yellow cat member of the cedar mountain formation which was deposited in a seasonally dry alluvial lacustrine setting although only 5 of the locality has been collected more than 4200 bones were recovered representing an assemblage overwhelmingly dominated by dinosaurs with a minimum of 67 individuals that represent at least eight genera the assemblage also includes eight elements from four non dinosaurian reptiles the dinosaur fauna is sauropod dominated mni minimum number of individuals 41 a basal macronarian mni 15 venenosaurus mni 3 a camarasaurid mni 2 and a large number mni 21 of generically unassigned sauropod elements other dinosaurs include the theropods utahraptor mni 9 nedcolbertia mni 2 a possible ornithomimid mni 2 plus a large iguanodontid mni 4 and the ankylosaurid gastonia mni 9 patterns of skeletal articulation and clustering ontogenetic representation and bone surface modification indicate that the assemblage accumulated and was exposed for more than a year as the result one or more multiple mass mortality events likely droughts that culled large numbers of subadults from the biocoenose carcasses and disarticulated elements were reworked then later transported a short distance and buried by a succession of debris flows skeletal representation data patterns of sorting breakage burrows abrasion and scratch marks provide evidence for sorting trampling and scavenging prior to debris flow reworking pre debris flow sorting is attributed to earlier hydraulic winnowing of easily transported elements the intensity and thoroughness of breakage involving 97 of the elements suggest highly focused high load impacts compatible with trampling by sauropods and iguanodontids lightly abraded and vertically displaced elements indicate episodes of trampling in soft mud trampling occurred before and after debris flow transport theropod tooth marks are uncommon but bone scavenging by osteophagous insects was common and severe resulting in substantial damage to articular surfaces comparisons of dw and other debris flow hosted bonebeds indicate that there are few consistent patterns among fossil assemblage and bone modification data however there are numerous similarities in the geological and spatial taphonomy datasets from these sites resulting from the similar physico hydraulic conditions under which elements were transported reworked and buried geologically and taphonomically dalton wells is similar to the blagoveshchensk monodominant hadrosaur bonebed in the udurchukan formation of eastern russia which also is interpreted as a debris flow hyperconcentrated flow deposit dalton wells also shares geologic and taphonomic characteristics with four bonebeds southeast of the town of green river utah and all occur at the base of the yellow cat member the uniform stratigraphic occurrences of the dalton wells blagoveshchensk and the green river sites resting on an unconformity and their shared sedimentologic and taphonomic features indicate that these sites originated in response to similar tectonic depositional and biostratinomic factors

terrestrial and marine records of the last glaciation from western tasmania do they agree abstract no neoglacial or late glacial readvances of ice are known from tasmania the main phase of glaciation occurred after 25 ka bp and attained a maximum slightly before 19 ka bp most ice had decayed by 14 ka bp but some may have survived at high altitude to 10 ka bp an early phase of ice advance prior to 47 ka bp is identified in the upper king valley pollen records of vegetation history show that herbaceous and alpine subalpine shrub vegetation communities were widespread in the lowlands during the late glacial stage and indicate a cold climate the middle last glacial stage vegetation was comprised mainly of subalpine shrub and woodland vegetation that suggests cool moist interstadial climatic conditions a marine pollen record from core so36 7sl suggests herbaceous and scrub vegetation development during isotope stage 4 preceded by wet forest at the end of stage 5

holocene flooding and species diversity in southwestern amazonia abstract a thick blanket of holocene alluvium lies over southwestern lowland amazonia and may possibly occur throughout much of the amazon basin these deposits resulted from massive seasonal flooding from about 11 000 to about 5000 yr b p that was followed by two cycles of erosion and deposition interpretations based on these geologic data suggest that southwestern lowland amazonia is ecologically an island in a state of supersaturated disequilibrium as a result of colonization from pleistocene refugia on its perimeter and that habitats of highest diversity may be the most recent in origin conservation efforts and studies of amazonian biogeography soils and paleoethnography should be reevaluated in light of the geologic data

time averaging overcompleteness and the geological record time averaging makes events that happened at different times appear to be synchronous in the geological record it can generate overcompleteness by concentrating objects e g fossils clasts from a longer time interval into a unit that formed during a shorter interval time averaging results both from extrinsic agents e g vertical mixing condensation analytical pooling of data and the intrinsic properties of the fossilized objects preservational potential and abundance variation in intrinsic and extrinsic factors results in disharmonious time aver aging different taxa preserved together may be time averaged over different time scales because extrinsic and intrinsic factors vary in time and space the geological record is characterized by vertical and lateral variations in time averaging the importance of time averaging depends on the time aver aging threshold which is determined by the time scale of the process of interest significant time aver aging occurs when the scale of temporal mixi

new taphonomic data of the 1 myr hominin butchery at untermassfeld thuringia germany abstract untermassfeld has provided a butchered bone assemblage and a mode 1 lithic record demonstrating hominin presence at a site which was classically viewed as paleontological this archaeological record was found during fieldwork and surveying in fluvial river banks and low to medium energy channel erosion sediments paleomagnetism and biostratigraphy has yielded an age for this hominin occupation close to the onset of the jaramillo subchron ca 1 07 myr in this paper we present new taphonomic data of the cut marked and hammer related bone material corresponding mainly to large sized herd species i e bison but also from cervids eucladoceros giulii and cervus s l nestii vallonnetensis and megafaunal species i e stephanorhinus hundsheimensis and hippopotamus amphibius antiquus distribution of skeletal elements and bone surface features suggests that this bone assemblage consists of animal remains with different taphonomic origins the assemblage formed during at most two or three sediment laden floods transporting both lithic tools and remains of animals that died of natural causes or were killed by predators the new taphonomic results presented here are important to analyze hominin colonization and adaptation to european mid latitude environments at 1 myr in competition for meat resources with large carnivores i e pachycrocuta brevirostris and panthera onca gombaszoegensis

taphonomy of some gondwana vertebrate assemblages of india abstract the gondwana formations of india comprising a thick succession of permo mesozoic continental sedimentary rocks occur in rift basins formed within the indian plate successions developed in some of the gondwana basins namely pranhita godavari damodar satpura and son mahanadi contain an array of vertebrate fossil assemblages among the four basins the pranhita godavari basin contains vertebrate assemblages from late permian middle and late triassic and early jurassic sediments an early triassic assemblage is known to occur in the damodar basin the satpura basin has yielded a middle triassic assemblage while a late triassic assemblage is known from the son mahanadi basin all these assemblages are confined mainly to the fluvial red bed successions taphonomic aspects of some of the assemblages of these gondwana basins are described here for the first time on the basis of the nature of occurrences of the skeletal assemblages six major taphonomic types termed here as a f have been identified from the gondwana basins of india type a includes complete articulated or semi articulated skeletons type b exhibits disarticulated skeletons of a large number of monospecific individuals type c is characterized by disassociated bones of monospecific individuals in a log jam condition type d exemplifies disarticulated bone assemblage of mixed individuals while isolated remains of single individuals belong to type e type f typifies isolated fragmentary bones analyses of these skeletal assemblages provide considerable information of death transportation and burial of the terrestrial vertebrates these results when integrated with the sedimentary features of the host rocks provide additional palaeoenvironmental and palaeocological information

formation process of pyrite polyframboid based on the heavy metal analysis by micro pixe pyrite framboid in sedimentary rocks could be concerned with arsenic contamination in groundwater of acidic environment and has been studied for the formation process of its unique morphology however not much has been discussed about the formation process based on the heavy metal distribution in pyrite framboids and their aggregates to reveal the formation process of pyrite framboids and their aggregates mudstone from the late cretaceous hakobuchi group central hokkaido japan are investigated for mode petrographical mineralogical and micro pixe particle induced x ray emission analysis in this study spherical and sub spherical pyrite framboids observed in polyframboids can be divided into two types based on the diameter of framboids d and the average diameter of microcrystals d within framboids type 1 ranging from 2 to 9 m and from 0 4 to 0 9 m respectively and type 2 ranging from 8 to 50 m and from 0 5 to 1 8 m respectively based on the quantitative traverse analyses and 2 d elemental mapping results by micro pixe heterogeneities in the concentrations of heavy metals within the analyzed aggregations of pyrite are exhibited on the basis of the as and pb zoning patterns the time range and chronological stages of pyrite aggregation growth are revealed

evidence for taphonomic size bias in the dinosaur park formation campanian alberta a model mesozoic terrestrial alluvial paralic system a study of the distribution of dinosaurian body masses in the dinosaur park formation dpf campanian southern alberta reveals a prominent negative skew a pattern distinct from those of modern terrestrial faunas we find a direct and robust correlation between taxon size estimated live body mass and known completeness there is a clear dichotomy between large and small bodied taxa at around 60 kg in which taxa less than 60 kg are significantly less complete mean completeness 7 6 than those with an estimated mass of 60 kg or greater mean 78 2 along with completeness there is also a strong association of body size and taphonomic mode with small taxa known largely from isolated and occasionally associated remains and large taxa known from articulated skeletons in addition there is a significant correlation between taxon body mass and both date of discovery and of description with taxa 60 kg the rates of both cumulative discovery and description for large taxa are best described by a logarithmic curve nearing an asymptote whereas small taxa show either a linear or power increase through time this suggests that our current knowledge of the large bodied dinosaur assemblage is reasonably representative of the true biological fauna with few discoveries likely to be made in the future however small taxa are greatly underestimated in both their diversity and abundance with many more potential discoveries to be made given that 1 the sedimentary deposits and fossil assemblages in the dpf together represent one of the best studied examples of a mesozoic alluvial paralic terrestrial palaeoecosystem and 2 similar patterns have been suggested but not documented for other mesozoic terrestrial ecosystems in the western interior of north america we suggest that this pattern of size bias may typify vertebrate fossil assemblages in terrestrial mesozoic systems if so such biases must be considered before patterns of diversity in dinosaur communities through time can be considered accurate or used to compare and interpret mesozoic palaeoecosystems

preliminary taphonomical studies of some pleistocene fauna from the central narmada valley madhya pradesh india abstract preliminary taphonomical studies carried out on a pleistocene faunal assemblages from the central narmada valley madhya pradesh india reveals that the assemblage has undergone hydrodynamic sorting resulting in the transportation of the fossils also there has been a delayed burial of the bones field sedimentological evidence supports the occurrence of the assemblage in channel deposits under the influence of moderate currents

the timing and cause of megafauna mass deaths at lancefield swamp south eastern australia abstract lancefield swamp south eastern australia was one of the earliest sites to provoke interest in pleistocene faunal extinctions in sahul pleistocene australia new guinea the systematic investigation of the deposit in the early 1970s identified megafaunal remains dominated by the 100 200 kg kangaroo macropus giganteus titan associated radiocarbon ages indicated that the species was extant until c 30 000 bp suggesting significant overlap with human settlement of sahul this evidence was inconsistent with contemporary models of rapid human driven extinctions instead researchers inferred ecological tethering of fauna at lancefield swamp due to intense drought precipitated localised mass deaths consistent with late pleistocene climatic variability later investigations in another part of the swamp the mayne site remote to the initial investigations concluded that mass flow disturbed this area and electron spin resonance esr analyses on megafauna teeth returned wide ranging ages to clarify site formation processes and dating of lancefield swamp we excavated new test pits next to previous trenches in the classic and mayne sites we compared absolute chronologies for sediments and teeth sedimentology palaeo topography taphonomy and macropod age at death across the swamp luminescence dating of sediments and esr analysis of teeth returned ages between c 80 000 and 45 000 years ago we found no archaeological remains in the bone beds and evidence of carnivore activity and fluvial action in the form of reactivated spring flow the latter disturbed limited parts of the site and substantial areas of the bone beds remained intact the faunal assemblage is dominated by megafaunal adult macropus consistent with mass die offs due to severe drought such droughts appear to have recurred over millennia during the climatic variability of marine isotope stages 4 and 3 these events began tens of millennia before the first appearance of aboriginal people in sahul and only the very youngest fossil deposits could be coeval with the earliest human arrivals therefore anthropogenic causes cannot be implicated in most if not all of mass deaths at the site climatic and environmental changes were the main factors in site formation and megafauna deaths at lancefield swamp

a new complete sequence from lower to middle paleolithic el provencio complex cuenca spain abstract this paper presents the results of the archaeological research project on the lower and middle paleolithic in the municipality of el provencio cuenca spain during the first 6 years of the project an unknown archaeological complex has been defined with a large concentration of remains of lithic industry of modes 1 2 and 3 as well as pleistocene faunal remains mammuthus and equus associated with the large scale sequences of the zancara river the first ages obtained by two complementary dating methods are presented here electron spin resonance esr and optically stimulated luminescence osl the absolute dates of 41 2 2 ka and 836 46 ka al ti mean age correspond to the upper and lower levels of the stratigraphic sequence respectively the archaeological potential contained in this complex suggests an effective and uninterrupted human occupation of this region during 800 ka