Conceptualising ‘fossiliferous deposit’ against ‘palaeontological deposit’: some semantic (and epistemological) considerations

This short essay intends to provide insight into the concepts of ‘fossiliferous deposit’ and ‘palaeontological deposit’ by identifying some of their semantic differences. From the moment that fossiliferous deposits are technically accessible to the palaeontologist, they are ‘palaeontological’ ones, but not before. However, not all palaeontological deposits must inevitably be ‘fossiliferous’ deposits in the sense of containing mineralised remains of the anatomical parts of organisms. As a consequence of the existence of fossiliferous deposits, the science of palaeontology exists, with the result that fossiliferous deposits become ‘palaeontological deposits’, together with the non-fossiliferous strata that are able to provide data on the ecological and/or ethological conditions of fossil beings from remains that are not ‘fossils’. From the point of view of philosophy of science, fossiliferous and palaeontological deposits should be considered as two different epistemological (as well as ontological) categories. Consequently, by identifying semantic differences, the concepts of ‘fossiliferous deposit’ and ‘palaeontological deposit’ can be framed better within the philosophical development of the palaeontological sciences. In addition to the central issue addressed in this essay, a brief discussion on the epistemic value of the dichotomy ‘to deposit’ versus ‘to reposit’ applied to palaeontological museology is brought up.     

Prospects of flora and vegetation reconstructions dependent on sediment petrological conditions, exemplified by eight Egerian floras of Hungary

Sediments of fossiliferous layers of eight Late Oligocene (Egerian) fossil plant sites located in the Hungarian Egerian basin were analyzed by grain-size distribution (wet sieving and laser grain-size distribution). Based on the previous flora and vegetation reconstructions the region defined by the site studied was covered at that time by relatively continuous and uniform zonal vegetation composed of paleotropical elements. Thus, the selected localities differ from one another only with regard to their stratigraphic setting, i.e. whether the fossils were obtained from deeper, more clayey or shallower, more sandy deposits of the oscillation sequence characteristic of the Egerian deposits. At least 50% of the sediment must belong to the mudstone fraction (<0.063 mm) if the majority of plant species are undoubtedly identifiable, while 70% or more, would be optimal, for which the site at Pomáz is a good example. The carbonate content of fossiliferous sediments significantly reduces the chance of good preservation and thus increases the number of unidentifiable taxa. Based on the comparison of plant fossil taxonomical studies, the grain-size distribution and the mineralogical composition of the fossiliferous sediments, a correlation was pointed out what conditions would be required by each taxon to yield identifiable specimens in the fossil record. According to the results of grain-size distribution the present study gives an opportunity—in the course of floristic studies and vegetation reconstructions—to develop a model reflecting the chance of the occurrence of each fossil taxon.     

Late Smithian microbial deposits and their lateral marine fossiliferous limestones (Early Triassic,Hurricane Cliffs,Utah, USA)

Recurrent microbialite proliferations during the Early Triassic are usually explained by ecological relaxation and abnormal oceanic conditions. Most Early Triassic microbialites are described as single or multiple lithological units without detailed ecological information about lateral and coeval fossiliferous deposits. Exposed rocks along Workman Wash in the Hurricane Cliffs (southwestern Utah, USA) provide an opportunity to reconstruct the spatial relationships of late Smithian microbialites with adjacent and contemporaneous fossiliferous sediments. Microbialites deposited in an intertidal to subtidal interior platform are intercalated between inner tidal flat dolosiltstones and subtidal bioturbated fossiliferous limestones. Facies variations along these fossiliferous deposits and microbialites can be traced laterally over a few hundreds of meters. Preserved organisms reflect a moderately diversified assemblage, contemporaneous to the microbialite formation. The presence of such a fauna, including some stenohaline organisms (echinoderms), indicates that the development of these late Smithian microbial deposits occurred in normal-marine waters as a simple facies belt subject to relative sea-level changes. Based on this case study, the proliferation of microbialites cannot be considered as direct evidence for presumed harsh environmental conditions.     

Biostratigraphy of Lower Permian foraminiferal assemblages from platform-slope carbonate blocks within the Mersin Mélange,southern Turkey: Paleogeographical implications

The Mersin Mélange (MM) as a part of the Mersin Ophiolitic Complex in southern Turkey is a sedimentary complex including blocks and tectonic slices within a Late Cretaceous matrix. Two blocks (Keven and Cingeypinari) within the MM originated from the northern branch of Neotethys (Izmir-Ankara-Erzincan Ocean) and have been studied in detail using foraminiferal assemblages to correlate them with coeval successions in the Taurides and to approach the Early Permian evolution of the northern branch of the Neotethys. The Keven block includes mainly slope deposits (poorly-sorted carbonate breccia and fossiliferous calcarenite) and dated as late Asselian-Sakmarian, whereas the Cingeypinari block consists of platform deposits (fossiliferous platform carbonate and quartz sandstone alternation) assigned to the Sakmarian-early Artinskian. These Early Permian Cingeypinari and Keven blocks from the Beysehir-Hoyran Nappes are biostratigraphically well correlated to the northerly originated Hadim nappe and its equivalents in the Tauride Belt. Considering recent studies on the Mersin Mélange, a possible mantle plume existed during the Late Carboniferous-Early Permian time interval along the northern Gondwanan margin. This event led to the opening of the northern Neotethys and deposition of the pelagic “Karincali” sequence with volcanic material in the basinal conditions. The data presented suggest that the Keven block relates to the slope and the Cingeypinari block to platform conditions deposited as a lateral equivalent of the Karincali sequences during the Early Permian.     

Belemnite ecology and the environment of the Nusplingen Plattenkalk (Late Jurassic,southern Germany): evidence from stable isotope data

The late Kimmeridgian Nusplingen Plattenkalk (palaeolatitude ~30°N) is one of the well‐known European Plattenkalk konservatlagerstätten. The laminated limestones of this lagerstätte have been deposited in a shallow lagoon, surrounded by sponge‐microbial mounds, some of which formed small islands. Plattenkalk sediments are often thought to have been deposited below a halocline, which was induced by high evaporation rates. By measuring the stable isotope composition of belemnite rostra (n = 27) of the species Hibolithes semisulcatus, the depositional environment of the Nusplingen Plattenkalk has been investigated. Cathodoluminescence‐microscopy and trace element analysis have been applied to check for diagenetic alteration of the studied rostra. The mean δ¹³C of the well‐preserved rostra is +0.03 ± 0.27‰, the mean δ¹⁸O ?0.68 ± 0.3‰. A narrow range of stable isotope data acquired from an accumulation of rostra, regurgitated by a fish or reptile, supports the notion that belemnite calcite reflects environmental conditions. The palaeontological and sedimentological findings suggest that H. semisulcatus was autochthonous to the Nusplingen Plattenkalk. Anoxic conditions prevailed in the sediments and temporarily in the water‐column above the sediment/bottom water interface. A nektobenthic life style can be excluded for the Nusplingen belemnites; a demersal life style seems unlikely. Comparison with δ¹⁸O_bel data from other latitudes indicates that a latitudinal gradient played a role in the δ¹⁸O composition of seawater. A pelagic, inner shelf setting is therefore suggested for the Plattenkalk, an interpretation that is supported by palaeontological evidence. It is here proposed that the formation of the Nusplingen Plattenkalk was not caused by salinity stratification. It is further suggested that the belemnites were not restricted to deep‐water settings, but also occurred in shallow waters and higher in the water‐column.     

Pre-Quaternary hominin settlements in Asia: Archaeology,bio-lithostratigraphy and magnetostratigraphy evidences at Masol,Siwaliks, Northwestern India

The National Museum of Natural History, Paris, the National Centre for Scientific Research (CNRS/UMR 7194 and 8148) and the Society for Archaeological and Anthropological Research, Chandigarh, conduct paleontological and archaeological surveys in a sub-Himalayan territory well known for its Upper Pliocene fossiliferous deposits and named the Quranwala Zone. Since 2007, the team is investigating this formation in the Masol anticline and has collected four fossils with marks of butchery as well as numerous lithic artifacts. In this paper we show the first chopper extracted in stratigraphy from the deepest fossiliferous layer at more than 2.6 Ma as shown by the undisputable magnetostratigraphy, we describe the lithostratigraphy of the excavation, the techno-typology of the chopper and compare it with the collection of its locality and two other major paleonto-archaeological sites of Masol. The characteristics of this Masol lithic assemblage do not match those of the early Lower Pleistocene African Oldowan (2.55 Ma), but they are similar to those of the Chinese lithic industry of Longgupo (2.5 Ma). These activities open new perspectives regarding the phylogenetic and geographical origins of these Asian hominins as well as on their descendants, and justify the pursuit of surveys and test pits in the Quranwala zone.     

Neochoiaella n. gen. (Demospongeae, Choiaellidae)—a second poriferan Lazarus taxon from the Solnhofen Plattenkalk (Upper Jurassic, Southern Germany)?

A new demospongid genus and species is described from the Upper Jurassic (Lower Tithonian) Plattenkalk of Langenaltheim near Solnhofen/Bavaria. Both the morphology and the spiculation of the new taxon Neochoiaella frattigianii n. gen. n. sp., which lacks a rigid skeleton, resemble the Early Cambrian family Choiidae de Laubenfels, 1955, particularly the genus Choiaella Rigby and Hou, 1995 from the Cengjiang Fossillagerst?tten of Yunnan/Southern China. Due to the complete preservation of the specimen, we cannot exclude the possibility that Neochoiaella n. gen. was living at its place of burial in the Plattenkalk basin of Solnhofen, but it seems more likely that it was washed in as an allochthonous faunal element, like other benthic organisms from this limestone. Similarly, the hexactinellid reticulate sponge Ammonella quadrata Walther, 1904, which appears to be restricted to the small Plattenkalk basin of Pfalzpaint, led to speculation about a possible Lazarus taxon due to its spicular architecture, which corresponds to that seen in the Early Palaeozoic Protospongiidae Hinde, 1887. Possibly, the special environmental conditions that existed within or close to the Plattenkalk basins provided a niche in which anachronistic taxa such as Neochoiaella n. gen. and Ammonella Walther, 1904 could have survived.     

Speleology and magnetobiostratigraphic chronology of the GD 2 locality of the Gondolin hominin-bearing paleocave deposits, North West Province, South Africa

Speleological, paleomagnetic, mineral magnetic, and biochronological analyses have been undertaken at the Gondolin hominin-bearing paleocave, North West Province, South Africa. Two fossiliferous but stratigraphically separate sequences, GD2 and GD1/3, which were once part of a large cavern system, have been identified. Although some comparative paleomagnetic samples were taken from the GD 1, 3, and 4 localities that are currently under investigation, the research presented here focuses on the fossil-rich, in situ deposits at locality GD 2, excavated by E.S. Vrba in 1979. The GD 2 deposits are dominated by normal-polarity calcified clastic deposits that are sandwiched between clastic-free flowstone speleothems. The lower flowstone has a sharp contact with the red siltstone deposits and is of reversed polarity. The capping flowstone shows a change from normal to reversed polarity, thereby preserving a polarity reversal. While the paleomagnetic work indicates that the GD 2 fossil material was deposited during a normal-polarity period, the shortness of the sequence made matching of the magnetostratigraphy to the geomagnetic polarity time scale (GPTS) impossible without the aid of biochronology. While lacking multiple time-sensitive taxa, the recovery of specimens attributable to Stage III Metridiochoerus andrewsi is consistent with a deposition date between 1.9 and 1.5 Ma. A comparison of the magnetostratigraphy with the GPTS therefore suggests that the fauna-bearing siltstone of GD 2 date to the Olduvai normal-polarity event, which occurred between 1.95 and 1.78 Ma, and that the reversal from normal to reversed polarity identified in the capping flowstone dates to 1.78 Ma. The main faunal layers therefore date to slightly older than 1.78 Ma. Deposits from the GD 1 locality are dominated by reversed directions of magnetization, which show that this deposit is not of the same age as the faunal layers from the GD 2 locality.     

First occurrence ofXerus cf.inauris (Rodentia,Sciruridae) at Olduvai Bed I (Lower Pleistocene,Tanzania)

PalZ - Some bonodont molars of a ground squirrel are attributed toXerus cf.inauris. Coming from Olduvai Bed I fossiliferous deposits they could represent an intermediate stage between the Laetoli...     

Hiatal shell concentrations, sequence analysis, and sealevel history of a Pleistocene coastal alluvial fan, Punta Chueca, Sonora

Richly fossiliferous marine sediments exposed along the Sonoran coastline of the Gulf of California near Punta Chueca provide an excellent setting in which to test (a) the strength of the association of skeletal concentrations with sedimentary hiatuses, (b) the utility of taphonomic evidence for reconstructing detailed histories of those non-depositional episodes, and thus (c) the largely unexploited potential of skeletal concentrations in the identification and interpretation of lithologically obscure unconformities and condensed sequences in shallow marine deposits. Sequence analysis based on discontinuity surfaces is possible in the complex, alluvial fan-to-shallow marine transition at Punta Chueca despite rapid facies changes. Progradation of depositional sequences that contain cobbles reworked from older terrace deposits indicates accumulation during a fall in eustatic sea level. The supratidal to subtidal conglomerates and sands contain a variety of predominantly molluscan shell concentrations that, on the basis of postmortem histories of shells, formed during periods of low net sedimentation (i.e. depositional hiatuses); the majority of these shell beds lie along discontinuity surfaces identified by independent physical stratigraphic evidence. Although not all discontinuity surfaces in the terrace are paved by shell material. and not all relative concentrations of shells indicate distinct discontinuities, the strength of the association between skeletal concentrations and stratigraphic hiatuses reveals the high degree of control on fossil occurrence by sedimentation rates, and indicates that skeletal concentrations can provide good clues to stratigraphically significant surfaces. Moreover, the detailed dynamics of non-depositional episodes are reliably revealed by taphonomic analysis of the associated fossil assemblages, improving interpretations of non-depositional episodes in local sedimentary history.     

Tafonomía de bivalvos holocenos en la costa del estuario de Bahía Blanca, Argentina

In the Bahía Blanca Estuary (Argentina), Holocene deposits are fossiliferous sand ridges originated by the last transgressive-regressive marine event. By means of ternary taphograms applied on valves of Brachidontes rodriguezi a taphonomic analysis was carried out in two ridges, both in the external and internal estuary area. Six taphonomic attributes were considered. The disarticulation and the fragmentation are higher in the external ridge, whereas the bioerosion and incrustation, both barely manifested, are similar in the two environmental settings. In the outer deposit, as much the abrasions as the dissolution of the shells are more intense. Genetically, it is considered that these shell concentrations were originated by multiepisodic storm events. Based on the taphonomic analysis, it arises that in the generation of the internal ridge waves of moderate energy with different sorting degrees prevailed, whereas in the formation of the external deposits waves of greater energy with smaller sorting capacity prevailed.     

Arvicolidae (Rodentia) from the Pliocene of Tollo de Chiclana (Granada, SE Spain)

Several new fossiliferous Pliocene localities have been identified in the continental deposits of the area of Tollo de Chiclana (Guadix Basin, SE Spain), that have yielded a rich rodent and insectivore fauna. In this paper, we study the Arvicolidae from these localities. Remains adscribed to the genera Dolomys, Mimomys and Kislangia have been found, which are very interesting from a biostratigraphical point of view.     

Siliciclastic input and sedimentation rate as controls on paleoecological distribution of Lower Miocene benthic carbonate producers in a fan–delta: Zagros foreland basin,Iran

This paper aimed to study Lower Miocene (Burdigalian) mixed carbonate–siliciclastic deposits within an Upper Cenozoic synorogenic conglomerate–dominated succession in north of Shalamzar in the Zagros foreland basin, Iran. The deposits are composed of nine facies: foraminiferal mudstone, silty mudstone, sandy mudstone, fossiliferous sandy mudstone, fossiliferous argillaceous mudstone, fossiliferous calclithite, coral limestone, calcareous claystone and hybrid sandstone. The facies represent a mixed carbonate– siliciclastic shelf–type fan–delta. The subenvironments of the fan–delta include muddy pro–delta, sandy delta– front, clastic proximal mouth bar and a subordinate delta plain. Siliciclastic input and sedimentation rate controlled the paleoecological distribution of different benthic carbonate–producing fauna in the fan–delta during its progradation into a shelf marine environment. Input of siliciclastic deposits and sedimentation rate limited the diversity and development of corals and controlled their colonization and growth morphologies in the sandy delta–front. Siliciclastic input (including plant materials and coal debris) and sedimentation rate controlled the trophic habitats of many gastropods and their abundance and distribution in the sandy delta– front and clastic proximal mouth bar. Also, increased siliciclastic input favored abundance of larger benthic foraminifera in most parts of the fan–delta with the exception of the muddy pro–delta.     

甘肃临夏盆地的渐新世巨犀化石

描述了 2种巨犀化石 :霍尔果斯准噶尔巨犀 (Dzungariotheriumorgosense)和牙沟副巨犀(新种 ) (Paraceratheriumyagouensesp .nov.)。新种的主要特征是 :个体小 ;上颊齿齿冠高 ,有薄层白垩质覆盖 ;DP2～M1反前刺大 ,原尖后收缩沟明显 ,次尖有深的前收缩沟 ,中谷和后凹中常有附属小柱等。巨犀的演化历史可能比过去想象的更复杂。Indricotherium、Dzungariotherium和Paraceratherium为代表不同进化水平和支系的 3个属 ,不应合并为Paraceratherium一属。牙沟含巨犀化石层位的地质时代为晚渐新世。     

New information on the postcranial skeleton of the Thalassodrominae (Pterosauria,Pterodactyloidea, Tapejaridae)

The clade Tapejaridae is composed by pterosaurs commonly found in fossiliferous deposits in northeastern Brazil. It is constituted by two less inclusive clades: the smaller-bodied Tapejarinae and the larger Thalassodrominae. Here we describe the specimen MN 6566-V, from the Lower Cretaceous Romualdo Formation of the Araripe Basin, Brazil. The specimen is overall well preserved tridimensionally, and consists of three posterior cervical vertebrae, incomplete right and left scapulocoracoids, and the proximal portion of a right humerus. Comparisons to specimens described in the literature enable its identification as a thalassodromine, whose postcranial material is still poorly known despite the large amount of pterosaurs known from this unit.     

Feeding ecology of Late Pleistocene Muntiacus muntjak in the Padang Highlands (Sumatra)

The Dubois Collectie comprises around 1000 isolated fossil teeth of Muntiacus muntjak from the Padang Highlands in Sumatra. The majority were retrieved from one of the three fossil cave sites Lida Ajer, Sibrambang or Jambu. Lida Ajer is the only cave, for which exact location, geology as well as the age of the fossiliferous deposits are known. Using the mesowear method, we searched for differences in the dietary signal of Muntiacus muntjak and thus in the paleoenvironments of the three caves. Muntiacus muntjak from either one of the caves does not differ significantly in the composition of its diet, showing a mixed feeder signal. The samples of Lida Ajer and Sibrambang illustrate an increase of the mixed feeding component, which could be the result of higher seasonality.     

Re-appraisal of the stratigraphy and determination of new U-Pb dates for the Sterkfontein hominin site, South Africa

Sterkfontein Caves is the single richest early hominin site in the world with deposits yielding one or more species of Australopithecus and possible early Homo, as well as an extensive faunal collection. The inability to date the southern African cave sites accurately or precisely has hindered attempts to integrate the hominin fossil evidence into pan-African scenarios about human evolutionary history, and especially hominin biogeography. We have used U-Pb and U-Th techniques to date sheets of calcium carbonate flowstone inter-bedded between the fossiliferous sediments. For the first time, absolute age ranges can be assigned to the fossil-bearing deposits: Member 2 is between 2.8 ± 0.28 and 2.6 ± 0.30 Ma and Member 4 between 2.65 ± 0.30 and 2.01 ± 0.05 Ma. The age of 2.01 ± 0.05 Ma for the top of Member 4 constrains the last appearance of Australopithecus africanus to 2 Ma. In the Silberberg Grotto we have reproduced the U-Pb age of ∼2.2 Ma of for the flowstones associated with StW573. We believe that these deposits, including the fossil and the flowstones, accumulated rapidly around 2.2 Ma. The stratigraphy of the site is complex as sediments are exposed both in the underground chambers and at surface. We present a new interpretation of the stratigraphy based on surface mapping, boreholes logs and U-Pb ages. Every effort was made to retain the Member system, however, only Members 2 and 4 are recognized in the boreholes. We propose that the deposits formally known as Member 3 are in fact the distal equivalents of Member 4. The sediments of Members 2 and 4 consisted of cone-like deposits and probably never filled up the cave. The U-Th ages show that there are substantial deposits younger than 400 ka in the underground cave, underlying the older deposits, highlighting again that these cave fills are not simple layer-cakes.     

Les nouveaux gisements villafranchiens du ravin de Cornillet (Moustiers Sainte-Marie,Alpes de Haute Provence,France) et leur contexte géologique

Several mammal remains were recently discovered in the Cornillet gully deposits: Nyctereutes megamastoides, Pachycrocuta perrieri, Dicerorhinus etruscus, Gazella borbonica. Eucladoceros senezensis, Croizetoceros ramosus. This fauna is attributed to the middle Villafranchian.The most recent beds of the Riez-Valensole basin include several superimposed units with three type of facies: fluvio-eolian (i. e. a conglomeratesand-silt sequence), lacustrine and breccian. The Upper Pliocene represented in the Puimoisson-Ségriès region by fossiliferous lacustrine deposits is covered with coarse detrital material. The Cornillet deposits can be found at the lower part of the calcareous formation continuing this Plio-Pleistocene stratigraphy.The breccias of Balène, located at the top ofthese formations, constitute a thick spread of the detrital material of cryoclastic origin. This spread appeared later than the tectonical thrust of the surrounding calcareous mountains upon the Tertiary basin.     

Exceptionally well‐preserved vegetal remains from the Upper Cretaceous of ‘Lo Hueco’, Cuenca,Spain

Vegetal remains are considered labile structures that quickly become decayed in ecosystems. However, certain lignified tissues (woody plants) can largely resist decomposition, becoming sometimes exceptionally well preserved. At the Upper Cretaceous site of ‘Lo Hueco’ (Cuenca, Spain), those woody remains (trunks and branches) with resinous material in the inner tracheids and parenchyma cells that were buried rapidly under anoxic conditions experienced a low degree of maturation, becoming exceptionally well preserved. Those woody remains deposited under oxic conditions (sub‐aerial or sub‐aquatic exposure) were more intensely biodegraded and subsequently carbonified, partially or completely mineralized in gypsum and covered by a ferruginous crust. These two modes of preservation are scarce, with silicification or carbonification processes much more common, and both can be considered as ‘exceptional preservation’. Other vegetal remains, such as carbonified leaves, stems and roots, were collected in the site. The different modes of preservation depend directly on: depositional micro‐environment (sandy distributary channel, muddy flood plain); and type (trunk, branch, stem, leave, root) and state (presence or absence of resinous material) of the material. The great abundance and diversity of fossils in ‘Lo Hueco’ identify it as Konzentrat‐Lagerstätten, sequentially formed by alternated events of flooding and drying depositional events, but the exceptional quality and rarity of determinate vegetal macroremains preservation suggest that certain deposits of this site can be considered as conservation deposits.     

A review of microbial-environmental interactions recorded in Proterozoic carbonate-hosted chert

The record of life during the Proterozoic is preserved by several different lithologies, but two in particular are linked both spatially and temporally: chert and carbonate. These lithologies capture a snapshot of dominantly peritidal environments during the Proterozoic. Early diagenetic chert preserves some of the most exceptional Proterozoic biosignatures in the form of microbial body fossils and mat textures. This fossiliferous and kerogenous chert formed in shallow marine environments, where chert nodules, layers, and lenses are often surrounded by and encased within carbonate deposits that themselves often contain kerogen and evidence of former microbial mats. Here, we review the record of biosignatures preserved in peritidal Proterozoic chert and chert-hosting carbonate and discuss this record in the context of experimental and environmental studies that have begun to shed light on the roles that microbes and organic compounds may have played in the formation of these deposits. Insights gained from these studies suggest temporal trends in microbial-environmental interactions and place new constraints on past environmental conditions, such as the concentration of silica in Proterozoic seawater, interactions among organic compounds and cations in seawater, and the influence of microbial physiology and biochemistry on selective preservation by silicification.