Fossiliferous Layers Research Articles

Glauconite Composition and Morphology, Shocked Quartz, and the Origin of the Cretaceous(?) Main Fossiliferous Layer (MFL) in Southern New Jersey, U.S.A.

Abstract The Main Fossiliferous Layer (MFL) is a concentration of vertebrate and invertebrate fossils, 20 to 30 cm thick, preserved in a sequence of glauconitic sand at or near the Cretaceous–Paleogene boundary in the New Jersey (USA) coastal plain. Several hypotheses have been proposed to explain the origin and age of the MFL, including: marine transgression and formation of lag deposits of reworked bones and shells, formation of a condensed section and attritional accumulation of fossil material, and catastrophic collapse of Late Cretaceous ecosystems following the end-Cretaceous bolide impact at Chicxulub. We use new data on glauconite morphology, concentrations, geochemistry, and presence of shocked quartz, coupled with previous data on sedimentology, taphonomy, and rare-earth-element geochemistry of fossil vertebrates to interpret the genesis of the MFL. Glauconite concentration and maturity steadily increases from latest Cretaceous sediments of the Navesink–New Egypt Formation, through the MFL and into the Paleogene upper Hornerstown Formation, suggesting that marine transgression and decreasing sedimentation rates were a factor in the formation of the glauconite, but not the MFL. Rare-earth-element patterns in fossil bones from the MFL, which are acquired during fossilization, are different from those of Cretaceous and Paleogene specimens, indicating that vertebrate remains in the MFL fossilized in situ and were not reworked from older, underlying units. Vertebrate fossils from the MFL are preserved as isolated to articulated specimens. While isolated specimens would be common in a transgressive lag, articulated specimens would not. Articulated specimens could be concentrated by attritional accumulation along a defined surface during a period of slow sedimentation, but the lack of a distinct increase in glauconite maturity or concentrations of elements associated with heavy-mineral accumulations at the Navesink–New Egypt–Hornerstown contact or MFL, which would be expected during a period of reduced sedimentation, hiatus, or unconformity, are absent at the localities studied. Shocked quartz was identified in a burrow fill directly beneath the MFL, at the contact of the Navesink and Hornerstown formations. Clay clasts with latest Cretaceous microfossils, along with reworked invertebrate fossils with infills of latest Cretaceous sediment, have been recovered from the MFL. The association of shocked quartz, mixture of isolated and articulated vertebrates with distinct rare-earth signatures, lack of a punctuated period of increased glauconite maturity, and presence of reworked Late Cretaceous invertebrates and clay clasts with Late Cretaceous microfossils suggests that the MFL may represent a thanatocoenosis that was the direct result of environmental disturbance associated with the end-Cretaceous impact event at Chicxulub.

CONTROLLED EXCAVATIONS IN THE ROMUALDO FORMATION LAGERSTATTE (ARARIPE BASIN, BRAZIL) AND PTEROSAUR DIVERSITY: REMARKS BASED ON NEW FINDINGS

Because of its fossil abundance and exceptional preservation, the Romualdo Formation of the Santana Group has become a famous lithostratigraphic unit of the Araripe Basin. In the past decades, much research has been conducted on the vertebrates of this unit, especially fish and pterosaurs, based mainly on museum collections. Despite the importance of these fossil finds, no stratigraphic information is known about them, because until recently, locals have collected most of the fossils. Here we present the results of the third controlled excavation of these layers. The data from all fossils collected confirm a faunal succession of fish biota. In the upper and most fossiliferous layer, the faunal composition shows a pattern of fish distribution never observed before, indicating that previous categories (abundance versus diversity) do not include the total diversity of fish populations. Pterosaur remains were recorded for the first time in the field, contradicting the general idea that these volant reptiles are common in the Romualdo strata. The specimen was attributed to the clade Anhangueridae because the proportional length of the first wing phalanx is less than twice the length of the wing metacarpal. The controlled excavation showed that the pterosaur assemblages from this formation probably occur in clusters. The known abundance of pterosaurs in the Romualdo Formation has been biased by just a few sites of fossil extraction, and these reptiles do not appear to have been as widespread or abundant as previously thought.

Palaeoclimatic information from isotopic signatures of Late Pleistocene Ursus ingressus bone and teeth apatite (Loutra Arideas Cave, Macedonia, Greece)

Bones and teeth samples of Ursus ingressus from Loutra Arideas Cave (Greece) were used to determine the diet of this extinct species and to reconstruct the palaeoclimatic conditions. The age range of the fossil layers is from 32 ka BP to a maximum of 38 ka BP (radiocarbon dating). The method used was the isotopic analysis of carbonate bioapatite of fossil cave bear ( U. ingressus) and brown bear ( Ursus arctos) bone and tooth fragments, as well as water samples from springs of the Pindos area, the modern bear habitat. Several possible effects that may affect the isotopic composition of apatite were investigated, including age, sex, tooth type and diagenesis. The comparison of isotopic values of Greek U. ingressus to other Pleistocene Ursidae species in Europe, exhibit more positive and more variable δ 13C values. These positive values are attributed mainly to diet, to bear physiology (differences among species) and to climate conditions. The diet of U. ingressus apparently was based mainly on vegetable matter, however with a variable component of animal protein. The variation observed in the δ 18O values of U. arctos tooth enamel samples were attributed to environmental conditions, and through the spring waters isotopic gradient for the region of Northeastern Pindos, to differences in the bear’s habitat elevation. Assuming similarity of the metabolism of modern and fossil bear species and incorporating only the effect of drinking water on the isotopic composition of body water, an equation has been derived that could be used to provide palaeoclimatic information.

Colonization of substrates: Vendian sedentary benthos

Studies of fossils sampled from a single fossiliferous layer (monotopic series) and a summary of previous data on taphonomy and morphology of Vendian macroorganisms suggest that most strategies of attachment of sedentary benthos were formed in the Vendian. These included: (1) free living with possible organic gluing; (2) fixation on the substrate using sucker-like structures and various incrustations; (3) fixation of the basal parts by shallow submergence in the sediment; (4) anchoring into the sediment with discoidal and rhizoid-like holdfasts; and (5) partial submergence and infaunal lifestyle. The most widespread fixation in the Vendian was the attachment by discoid organs, which can be interpreted as symbiotrophic structures. Symbiotrophy in Vendian organisms submerged in the anoxic sediment can apparently be supported by indirect evidence: structural diversity of basal organs, their complex morphology, large area of contact with substrate, unlimited isometric growth, predominant fossilization of attachment discs; inconsistent systematization of organisms.

MERCURY REMOVAL BY SOME SOILS OF JAPAN FROM AQUATIC ENVIRONMENT

This study investigates the efficiency of six types of soil, upper, lower and shell fossil layer of shirasu soils of Kagoshima; tuff soil of Shimane; Akadama and Kanuma soils of Tochigi, Japan in removing Hg from aquatic phase by analyzing the morphological and chemical properties. Morphological and chemical characterization of each soil was executed by SEM-EDS analysis as well as Hg removal study was performed by batch operation mode. SEM-EDS characteristics revealed soils particles predominantly constituted of SiO2 (21.8–78.5%), Al2O3 (4.1 – 38%) and FeO (0.8 – 7.7%) in all soil types excepting tuff soil where CaO showed highest percentage (65.3%). Organic matter and CuO were exclusively observed in Kanuma and Akadama soils. A critical appraisal of total Hg removal (36.4 – 48.15 μg/L) data clearly revealed that though maximum Hg removal efficiencies were observed in Kanuma (0.27μg/L/g/h) and Akadama (0.26 μg/L/g/h) soils, but former one was superior. Obtained results also demonstrated Hg removal of soils is potentiality governed by higher percentage Al2O3 lower percentage SiO2, CuO and organic matter content of soils. Therefore, it may be concluded that Kanuma and Akadama soils can be used as a low-cost potential Hg adsorbing agent for treating the Hg contaminated effluents in order to reclaim the aquatic environment.

Pleistocene seasonal temperature variations recorded in the δ18O of Bison priscus teeth

Oxygen isotope analysis of phosphate in tooth enamel of mammals ( δ 18O p) constitutes a valuable method to reconstruct past air temperatures in continental environments. The method is based on interdependent relationships between the δ 18O of apatite phosphate, body fluids, environmental waters and air temperatures. Continuous tooth growth and absence of enamel remodelling in bovid teeth ensures a reliable record of the intra-annual variability of air temperature through an incremental δ 18O analysis from apex to cervix. This method has been applied to Bison priscus dental remains of the late Middle Pleistocene from the fossiliferous layer of a cave at Coudoulous I in South-Western France (Layer 4). The stacked oxygen isotope signal obtained by combining 9 bison teeth shows sinusoidal variations (15.0‰ to 19.1‰ V-SMOW) of seasonal origin over 2.5 yr. The corresponding computed MAT of 9 ± 3 °C is about 4 °C lower than at present. Seasons appear more contrasted in Coudoulous I during Layer 4 deposition with summers as warm as present ones (19 ± 3 °C) and significantly colder winters about 0 ± 3 °C compared to 6 ± 1 °C at present.

A new magnetostratigraphic framework for late Neogene Hipparion Red Clay in the eastern Loess Plateau of China

Mammalian fossils, especially the Hipparion fauna, found in the Red Clay of the Loess Plateau, are of immense value for reconstructing late Neogene paleoecology and paleoclimatology in northern China. The lack of a precise chronological framework for these fossil sites has impeded our understanding of the evolution of the Chinese mammalian fauna, their correlation with European mammalian units, and the retrieval of paleoclimatic information. In this study, a field survey of regional stratigraphy in the Baode area of Shanxi was carried out and three profiles (Tanyugou, Yangjiagou-I and Yangjiagou-II) of Late Neogene deposits were selected for detailed investigation. A new chronological framework of the Late Neogene sequences in the Baode area is established by means of paleomagnetism. Our results show that the Red Clay accumulation in the Baode area began at least 7.23 Ma ago. Deposition continued to the superposed Jingle Formation. The most continuous and complete exposure of the Jingle Formation known to date was identified and dated to 2.72~5.34 Ma. A lithological distinction between the Jingle Formation and the underlying Baode Formation forms a clear boundary in the Red Clay that is not coincident with the Miocene/Pliocene boundary documented elsewhere. Three rich fossil layers are found in the Yangjiagou-II profile and dated to 6.43–6.54 Ma, 6.83–6.86 Ma and 7.15–7.18 Ma, respectively. With the application of three different demagnetization techniques, the Matuyama–Gauss geomagnetic reversal boundary was identified in a transitional unit between loess and typical Red Clay deposits. A lock-in depth of as large as 6.8 m (corresponding to ca. 65 ka) was inferred but remains unexplained.

Otolith atlas for the western Mediterranean, north and central eastern Atlantic

The sagittal otolith of 348 species, belonging to 99 families and 22 orders of marine Teleostean fishes from the north and central eastern Atlantic and western Mediterranean were described using morphological and morphometric characters. The morphological descriptions were based on the otolith shape, outline and sulcus acusticus features. The morphometric parameters determined were otolith length (OL, mm), height (OH, mm), perimeter (P; mm) and area (A; mm 2 ) and were expressed in terms of shape indices as circularity (P 2 /A), rectangularity (A/(OL×OH)), aspect ratio (OH/OL; %) and OL/fish size. The present Atlas provides information that complements the characterization of some ichthyologic taxa. In addition, it constitutes an important instrument for species identification using sagittal otoliths collected in fossiliferous layers, in archaeological sites or in feeding remains of bony fish predators.

La Grotte des Félins, site paléolithique du Pléistocène supérieur à Dar Bouazza (Maroc)

In the continental sediments filling a cave that developed in Middle Pleistocene deposits near Casablanca, Morocco, a very rich mammal fauna from the last climatic cycle was discovered. It was associated with a Middle Palaeolithic poor and atypical lithic assemblage manufactured on blocks and pebbles. The lower fossiliferous layer contained abundant carbonized remains of felids. Unfortunately, the site was destroyed by quarrying before adequate excavations could be carried out.

Nouveaux gisements à rongeurs dans le Miocène moyen continental du Bassin d'Aït Kandoula (Maroc)

The Azdal section in the Aït Kandoula basin show a succession of four fossiliferous layers delivering micromammals particularly rodents are very abundant than the great mammals. Mellalomys kandoulati nov. sp. is described in the oldest layer of the section. Compared to the Middle Miocene fauna of North Africa all the species from different layers are not yet reach the evolutionary stage of those of Pataniak 6. The old level has an age similar to those of Beni Mellal. The magnetostratigraphic study allows to situating these fore layers in chron C5An.2n and C5AAn.

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.

Présence d'un Gomphotheriidae indet. (Proboscidea, Mammalia) dans la faune vallésienne d'Afoud AF6 (Bassin d'Aït Kandoula, Maroc), établie d'après la microstructure de l'émail d'un fragment de molaire

The Aït Kandoula basin is one of the richest Miocene micromammals bearing areas known in the South of the High-Atlas, whereas the large mammal remains are scarce. The Afoud section in the center of the basin is well calibrated with the Geomagnetic Polarities Time Scale (KC95), and shows a succession of six fossiliferous layers. Beside rodents, the Afoud AF6 layer yields among some large mammal remains, a proboscidean identified as a Gomphotheriidae indet. from the enamel microstructure of a molar chip. This determination is grounded on the thickness of the enamel, on the prisms type, on the thinness and characteristics of the 3D zone and outside on the preferential course of the prisms.

THE GEOLOGICALLY YOUNGEST ALBANERPETONTID AMPHIBIAN, FROM THE LOWER PLIOCENE OF HUNGARY

: The Albanerpetontidae are salamander-like, Middle Jurassic to Neogene lissamphibians from Laurasia and North Africa. Extensive series of albanerpetontid bones recently identified in collections from the Csarnota 2 locality, south-central Hungary, extend the temporal range of the clade forward about seven million years from the middle Miocene to the early Pliocene. The Hungarian material is diagnostic for the Euramerican type genus Albanerpeton and pertains to a new species, A. pannonicus sp. nov., which differs from the seven previously reported congeners (Early Cretaceous–Miocene) in a distinctive combination of primitive and derived character states of the jaws and frontals, including a unique ventromedian keel on the azygous frontals. Some of the Hungarian specimens are articulated sets of skull bones, including ones containing the first three-dimensional examples of a nasal and jugals known for albanerpetontids, that help clarify some details of cranial osteology in these amphibians. Cladistic analysis nests A. pannonicus within the robust-snouted clade, as the sister taxon to an unnamed late Palaeocene species from Canada and A. inexpectatum from early–middle Miocene deposits in France, Austria and Germany. This phylogeny and recent reports of diagnostic Albanerpeton material from the Campanian of France and Maastrichtian of Romania suggest the evolutionary history of Albanerpeton was more complex than previously hypothesized, with Europe having played a larger role. The 25 fossiliferous layers at Csarnota 2 record a shift from forest to grassland palaeoenvironments. Fossils of A. pannonicus are present in all layers, implying that this species was not adversely affected by the change in palaeoenvironments.

Evaluation of the Olduvai subchron in the Orce ravine (SE Spain). Implications for Plio-Pleistocene mammal biostratigraphy and the age of Orce archeological sites

The Barranco de Orce (BO) section in the Baza basin (SE Spain) exposes several fossiliferous layers (O-1 to O-7) with Plio–Pleistocene micro- and macromammals. Biostratigraphic and magnetostratigraphic data from this and other sections in the basin have been extensively used to calibrate the Plio–Pleistocene chronology based on mammal biozonations. Because of its stratigraphic and geographic proximity, the BO section has also been used to date the paleontological and archeological sites of Barranco León, Fuentenueva-3 and Venta Micena. This study shows that the BO section crosses a mega-landslide that produces partial repetitions of the sedimentary sequence. The seven fossiliferous layers are actually the repetition of only two (O-6 and O-7) which are found in situ in the upper part of the ravine. New paleomagnetic results demonstrate the presence of Reverse magnetization throughout this section, contradicting the Normal event previously reported and assigned to the ‘Olduvai’ subchron (C2n). Published and new magnetostratigraphic data show that all archeological and paleontological sites in the Orce area are within a Reverse magnetochron, presumably C1r.2r (late Matuyama). The use of BO in the magnetobiostratigraphical calibration of the Pliocene/Pleistocene boundary for western Europe is not advised.

The late Oligocene birds of the Créchy quarry (Allier, France), with a description of two new genera (Aves: Pelecaniformes: Phalacrocoracidae, and Anseriformes: Anseranatidae)

The late Oligocene birds of the Crechy quarry (Allier, France) with a description of two new genera (Aves: Pelecaniformes: Phalacrocoracidae, and Anseriformes: Anseranatidae). The Crechy quarry includes several fossiliferous layers, the fauna of which has been dated by micromammals to the latest Oligocene (reference-levels MP 29 and MP 30). Most of the birds belong to the same species as those which are widespread in the early Miocene localities (MN 2a) of the Saint-Gerand-le-Puy area. However, they differ from these Miocene avifaunas by the presence of a primitive form of Phalacrocoracidae,Borvocarbo guilloti n. gen. n. sp., and by a small representative of the Recent family Anseranatidae,Anserpica kiliani n. gen. n. sp. Most of these forms are aquatic birds which probably lived on lakes or on their shores.

Les Cervidae du gisement Pliocène supérieur (Villafranchien moyen) de Saint-Vallier (Drôme, France)

The biometric and morphologic study of the Cervids remains from the Mid-Villafranchian deposit of Saint-Vallier (Drôme, France) was presented. Three Cervid taxa are recognized in the upper fossiliferous layer (LD3): “ Cervus” philisi valliensis, C. ramosus medius and Eucladoceros ctenoides vireti. The first and the second are the most abundant species in the site. Their post-cranial bones are described and compared with some recent Cervids like Fallow Deer (genus Dama) and Red Deer ( Cervus elaphus). The characters linking “ C.” philisi with the recent Fallow Deer are recognized. If “ C.” philisi and C. ramosus teeth and antlers are diagnostic, the post-cranial bones determination is less simple: the best character to determinate them is the size, but it is not always fruitful. I show that a combination of size, bone proportions and morphological characters allows us to discriminate the two species. The third taxon instead is larger and cannot be mistaken with the others. Two Cervid taxa are found in the lower fossiliferous layer (LD2): a large species and a small one. Morphologically and biometrically, they are very similar to Eucladoceros ctenoides vireti and C. ramosus medius from the upper layer, and they could belong to the same subspecies. The presence of a third species (?“ Cervus” philisi) is probable but not sure.

Les Bovidés du gisement pliocène supérieur (Villafranchien moyen) de Saint-Vallier (Drôme, France)

A biometric and morphologic study of the Bovid remains from the Mid-Villafranchian deposit of Saint-Vallier (Drôme, France) is presented. Three Bovid taxa are recognized in the upper fossiliferous layer (LD3): Leptobos (Leptobos) elatus merlai, Gazella borbonica and Gazella sp. Two Bovid taxa are also found in the lower fossiliferous layer (LD2): Leptobos cf. elatus merlai and Gallogoral meneghinii. The first one is very similar, morphologically and biometrically, to Leptobos from LD3 level. The second species was only found on the lower level. No bones belonging to Gazellospira torticornis were discovered during the most recent excavations.

Reconnaissance par sismique-réfraction du gisement de Saint-Vallier

Seismic-refraction prospections was carried out to follow the extension of indurated layers, especially the fossiliferous layers LD2 and LD3. Acquisition of data was difficult because of large vertical and lateral variability in sedimentological and geometrical characteristics of deposits. However, the prospection allowed to find the approximate limits of indurated layers.

Preliminary 14C Dates on Bulk Soil Organic Matter from the Black Creek Megafauna Fossil Site, Rocky River, Kangaroo Island, South Australia

Radiocarbon age determinations and stratigraphy suggest that the deposits in Black Creek Swamp on Kangaroo Island record 3 phases of deposition and associated soil development which spanned at least the last 20,000 yr. Four new 14C age determinations on bulk soil organic matter and their stratigraphic context are presented in this paper. Three of these age determinations (FP6: 15,687 ± 110 BP [WK11487]; FP7: 16,326 ± 385 BP [WK11488]; and FP8: 17,618 ± 447 BP [WK11489]), are from the organic-rich fossil layer located 45–75 cm below the current floodplain surface. The fourth, a much younger date, FP5: 5589 ± 259 BP (WK11486), was obtained from the base of the overlying modern soil. The dates for the fossil layer increase systematically with depth and correlate well with 5 previous 14C dates (Hope et al., unpublished), ranging between 15,040 ± 120 BP and 19,000 ± 310 BP. This suggests that the data set represents a possible minimum age of the bulk organic matter, and considering the high organic matter contents of approximately 8%, has implications for the age of the megafauna buried in this layer. The overlying modern soil, with its much younger date, contains lower levels of organic matter (3–7%) and gastropods not seen in the fossil layer. This suggests a substantial change in environmental conditions probably due to an alteration in the floodplain drainage conditions. This chronological and sedimentalogical discontinuity indicates that 2 distinct depositional regimes existed and were separated by up to 10,000 14C yr. A calcareous, sandy silt deposit underlying the fossil layer is a calcarenite deposit with low total organic content and is considered the base of the section; it suggests a third separate depositional episode. As such, the Black Creek Swamp in the southwest corner of Kangaroo Island formed intermittently over at least the last 20,000 yr during 3 distinct depositional phases, one of which was the formation of the fossil-laden, organic-rich floodplain surface, which has a possible minimum age of approximately 15,000 to 19,000 BP.

K-bentonites, volcanic ash preservation, and implications for Early to Middle Devonian volcanism in the Acadian orogen, eastern North America

Lower to Middle Devonian marine strata in the Appalachian foreland basin feature up to 80 or more thin K-bentonites that represent ancient volcanic ashes. The time vs. space distribution of K-bentonites through the Lochkovian to Eifelian Stages (representing ∼30 m.y.) shows a distinct pattern of clustered multiple beds, several scattered beds, and thick intervals with no K-bentonites. Four clusters of 7 to 15 individual, closely spaced layers occur in the middle Lochkovian (Bald Hill K-bentonites, Kalkberg–New Scotland Formations), late Pragian or early Emsian (Sprout Brook K-bentonites, Esopus Formation) and early Eifelian (two clusters, the Tioga middle coarse zone and Tioga A–G K-bentonites, Onondaga Formation). Detailed examination of these Devonian K-bentonites shows that in many cases they do not represent a single eruption. Multilayered beds, fossil layers within beds, authigenic minerals (e.g., glauconite and phosphate nodules), subjacent hardgrounds, and an irregular distribution of beds through space and time raise questions about the depositional history and preservation potential of volcanic ash in marine environments and the degree to which the beds represent a primary record of volcanism. These and other lines of evidence indicate that postdepositional physical, biological, and geochemical processes (e.g., sedimentation rate, event, and background physical processes, burrowing) have modified the primary record of these water-laid ash-fall events. These factors may lead to preservation of primary ash deposits or to their resedimentation and/or partial to complete mixing with background sediments. The preservation potential, and resulting distribution, of the Devonian K-bentonites can be analyzed across a spectrum of preservational magnafacies. In this paper I present a model of ash preservation; the model incorporates environmentally related physical, biological, and chemical processes active in epicontinental seas and marine foreland basins. Conclusions based on the model indicate that the middle Lochkovian, early Emsian, and early Eifelian were times of peak volcanic activity in eastern North America, related to times of increased tectonism in the Acadian orogen.