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31.
Stephen F. Poropat Jay P. Nair Caitlin E. Syme Philip D. Mannion Paul Upchurch Scott A. Hocknull 《Alcheringa: An Australasian Journal of Paleontology》2017,41(4):543-580
Poropat, S.F., Nair, J.P., Syme, C.E., Mannion, P.D., Upchurch, P., Hocknull, S.A., Cook, A.G., Tischler, T.R. &; Holland, T. XX.XXXX. 2017. Reappraisal of Austrosaurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous sauropod dinosaur. Alcheringa 41, 543–580. ISSN 0311-5518Austrosaurus mckillopi was the first Cretaceous sauropod reported from Australia, and the first Cretaceous dinosaur reported from Queensland (northeast Australia). This sauropod taxon was established on the basis of several fragmentary presacral vertebrae (QM F2316) derived from the uppermost Lower Cretaceous (upper Albian) Allaru Mudstone, at a locality situated 77 km west-northwest of Richmond, Queensland. Prior to its rediscovery in 2014, the type site was considered lost after failed attempts to relocate it in the 1970s. Excavations at the site in 2014 and 2015 led to the recovery of several partial dorsal ribs and fragments of presacral vertebrae, all of which clearly pertained to a single sauropod dinosaur. The discovery of new material of the type individual of Austrosaurus mckillopi, in tandem with a reassessment of the material collected in the 1930s, has facilitated the rearticulation of the specimen. The resultant vertebral series comprises six presacral vertebrae—the posteriormost cervical and five anteriormost dorsals—in association with five left dorsal ribs and one right one. The fragmentary nature of the type specimen has historically hindered assessments of the phylogenetic affinities of Austrosaurus, as has the fact that these evaluations were often based on a subset of the type material. The reappraisal of the type series of Austrosaurus presented herein, on the basis of both external morphology and internal morphology visualized through CT data, validates it as a diagnostic titanosauriform taxon, tentatively placed in Somphospondyli, and characterized by the possession of an accessory lateral pneumatic foramen on dorsal vertebra I (a feature that appears to be autapomorphic) and by the presence of a robust ventral mid-line ridge on the centra of dorsal vertebrae I and II. The interpretation of the anteriormost preserved vertebra in Austrosaurus as a posterior cervical has also prompted the re-evaluation of an isolated, partial, posterior cervical vertebra (QM F6142, the ‘Hughenden sauropod’) from the upper Albian Toolebuc Formation (which underlies the Allaru Mudstone). Although this vertebra preserves an apparent unique character of its own (a spinopostzygapophyseal lamina fossa), it is not able to be referred unequivocally to Austrosaurus and is retained as Titanosauriformes indet. Austrosaurus mckillopi is one of the oldest known sauropods from the Australian Cretaceous based on skeletal remains and potentially provides phylogenetic and/or palaeobiogeographic context for later taxa such as Wintonotitan wattsi, Diamantinasaurus matildae and Savannasaurus elliottorum.Stephen F. Poropat* [sporopat@swin. edu. au; stephenfporopat@gmail. com] Department of Chemistry and Biotechnology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Jay P. Nair [j. nair@uq. edu. au; jayraptor@gmail. com] School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Caitlin E. Syme [caitlin. syme@uqconnect. edu. au] School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Philip D. Mannion [philipdmannion@gmail. com] Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; Paul Upchurch [p. upchurch@ucl. ac. uk] Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK; Scott A. Hocknull [scott. hocknull@qm. qld. gov. au] Geosciences, Queensland Museum, 122 Gerler Rd, Hendra, Queensland 4011, Australia; Alex G. Cook [alex. cook@y7mail. com] School of Earth Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Travis R. Tischler [travisr. tischler@outlook. com] Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia; Timothy Holland [drtimothyholland@gmail. com] Kronosaurus Korner, 91 Goldring St, Richmond, Queensland 4822, Australia. *Also affiliated with: Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia. 相似文献
32.
We predict that portions of the New Jersey continental slope were unstable approximately 0.5 million years ago. This instability was caused by rapid sediment loading during a Pleistocene sea‐level lowstand and by flow focusing in underlying, permeable Miocene strata. The simulated instability is consistent with soft‐sediment deformation and small slumps in Pleistocene strata of the Hudson Apron. Stability of the New Jersey margin has increased since 0.3 Ma because sedimentation rate has decreased. Today, the modelled factor of safety (FS) for the upper slope is approximately 1.5 whereas in the lower slope it exceeds 3. We predict that sedimentation rate is a dominant factor on slope stability. When rapid and asymmetric loading of a highly permeable sedimentary layer occurs, the location of instability can shift seaward to regions where sedimentation rates are low. Stability calculations use pressures and effective stresses predicted by a coupled sedimentation‐fluid flow model. This hydrodynamic analysis demonstrates how the interplay of sedimentation and fluid migration affects the distribution, timing, and size of sedimentary failures. 相似文献
33.
E. Tema F. Fantino E. Ferrara A. Lo Giudice J. Morales A. Goguitchaichvili P. Camps F. Barello M. Gulmini 《Journal of archaeological science》2013
A combined archaeomagnetic and thermoluminescence study was carried out as part of a rescue archaeological excavation on a kiln discovered during the installation of methane gas pipelines beneath a rice field, along the southern border of Fontanetto Po village (Vercelli province, Italy). A total of 23 independent brick samples have been collected, oriented in situ with an inclinometer; the use of magnetic and sun compass was not possible due to the existence of metallic tubes beneath the kiln and a plastic cover above it. Standard archaeomagnetic procedures have been used for the determination of the archaeomagnetic inclination and absolute geomagnetic intensity. Stepwise thermal demagnetization shows a very stable characteristic remanent magnetization and the calculated mean inclination of the 23 samples is I = 65.3° with α95 = 2.4° and k = 156. Archaeointensity experiments have been performed using the classical Thellier method as modified by Coe, with regular partial thermoremanent magnetization (pTRM) checks. The cooling rate and remanence anisotropy effects upon thermoremanent magnetization (TRM) have been investigated in all the specimens. A total of 19 archaeointensity determinations (at specimen level) that correspond to linear NRM–TRM plots were used for the calculation of the site mean archaeointensity that is 46.4 ± 2.9 μT. Archaeomagnetic dating results show two possible dating intervals for the last 1000 years, calculated at 95% confidence interval: a first one from 1511 to 1614 AD, and a second one from 1768 to 1872 AD. Thermoluminescence (TL) study has been also performed on two brick samples from the kiln's internal wall, using conventional laboratory procedures. According to the thermoluminescence results the kiln's last usage lies between 1796 and 1914 AD. This age is in good agreement with the second dating interval obtained by the archaeomagnetic analysis. The combined archaeomagnetic and thermoluminescence results suggest that the last firing of the kiln could have occurred between the end of the 18th century and the beginning of 20th century. 相似文献
34.
A. Perea P.C. Gutiérrez-Neira A. Climent-Font P. Fernández-Esquivel S. Rovira-Llorens J.L. Ruvalcaba-Sil A. Verde A. Zucchiatti 《Journal of archaeological science》2013
One of the most important pre-Columbian gold assemblages made up of more than one hundred objects from two tombs in the Cauca river valley, Colombia, was studied to obtain archaeometric information. Although several attempts have been made to arrange gold production in time and space from the stylistic point of view, no firm conclusions were possible due to the lack of archaeological contexts. This paper presents first results of a new, fully instrumental approach, in which different analytical techniques, including OM, SEM-EDS, XRF, PIXE, RBS, AMS and X-ray imaging, were applied in order to determine a technological, metallurgical and chronological frame of the so-called Quimbaya Treasure. 相似文献
35.
Karen J. Taylor Aaron P. Potito David W. Beilman Beatrice Ghilardi Michael O'Connell 《Journal of archaeological science》2013
This study provides a unique method of inquiry for archaeological investigation with an aim to assess the intensity and effects of Neolithic and Bronze Age farming practices at Lough Dargan, northwest Ireland, through a multi-proxy analysis of a lake sediment core. Chironomid (non-biting midge fly) subfossils and lake sediment geochemistry (δ13C, δ15N and C:N ratios) were used to assess changes in limnological conditions through time. The limnological data were compared with macroscopic charcoal concentration and pollen data to examine the potential influence that early farmers had on a freshwater lake system within a prehistorically active catchment. Results from the chironomid analysis show that the first substantial period of agricultural activity in the early Neolithic (c. 3730–3190 BC) resulted in a temporary shift to more eutrophic lake conditions. There is evidence of animal husbandry with substantial levels of animal waste reaching the lake, leaving an imprint in the geochemical record of increased δ15N values and decreased δ13C values and C:N ratios during this time. The chironomid community reverted back to its pre-impacted state c. 3190 BC in response to a period of reduced farming (c. 3390–3000 BC) which eventually led to a distinct lull in activity, with possible cessation of farming from 3000 to 2700 BC. A return to eutrophic conditions coincided with the gradual return of agriculture, with more permanently altered lake conditions dominating from 2400 BC, even during a 250-year period of reduced human activity commencing at c. 1440 BC. Increased sedimentation rate, along with increases in δ13C, δ15N and C:N, the presence of chironomid taxa indicative of erosion, more eutrophic lake conditions and high concentrations of macroscopic charcoal all point to more intensive land use practices during the Bronze Age. Palaeolimnological data exhibited an immediate response to intensified farming during this time, and were especially responsive to pastoral farming due either to scale of activity or proximity to the lakeside. The success of this study demonstrates the effectiveness of palaeolimnological analysis in the investigation of prehistoric farming. This approach will help inform Neolithic and Bronze Age land-use practice and human–environment relations in the region, and highlights the potential for chironomid-based archaeological research. 相似文献
36.
This paper considers Frobisher Bay and Inuvik, two Canadian Arctic towns, as examples of the high-modernist planning that swept the globe during the middle decades of the twentieth century, but also Cold War projects reflecting a sudden interest in the Arctic as a region of military significance. Building on the framework provided by James Scott in Seeing like a State (1998), the paper details the connections between modernization theory and Cold War militarism before turning to the strikingly parallel case studies. In each instance, federal officials proposed ambitious urban models designed to simultaneously overcome the hostility of a northern environment and catapult native northerners into conditions of modern living. While the limits and failings of such schemes varied by location, both sites were also laboratories for social scientists employed by the federal government to document and analyze the modernization of the Arctic. The work of these scholars represents a particularly rich and complex record of governmental interventions, tied variously to Cold War imperatives, in northern lives and landscapes at a time of great faith in the transformative power of modern engineering. 相似文献
37.
J. P. FAIRLEY 《Geofluids》2009,9(2):153-166
Previous studies have shown that most hydrothermal systems discharging at the land surface are associated with faulting, and that the location, temperature and rate of discharge of these systems are controlled by the geometry and style of the controlling fault(s). Unfortunately, the transport of heat and fluid in fault-controlled hydrothermal systems is difficult to model realistically; although heterogeneity and anisotropy are assumed to place important controls on flow in faults, few data or observations are available to constrain the distribution of hydraulic properties within active faults. Here, analytical and numerical models are combined with geostatistical models of spatially varying hydraulic properties to model the flow of heat and fluid in the Borax Lake fault of south-east Oregon, USA. A geometric mean permeability within the fault of 7 × 10−14 m2 with 2× vertical/horizontal anisotropy in correlation length scale is shown to give the closest match to field observations. Furthermore, the simulations demonstrate that continuity of flow paths is an important factor in reproducing the observed behavior. In addition to providing some insight into possible spatial distributions of hydraulic properties at the Borax Lake site, the study highlights one potential avenue for integrating field observations with simulation results in order to gain greater understanding of fluid flow in faults and fault-controlled hydrothermal and petroleum reservoirs. 相似文献
38.
Dominik?Paw?owskiEmail author Marek?Kloss Milena?Obremska Mateusz?Szymanowski S?awomir??urek 《Geochronometria》2012,39(2):133-148
This paper demonstrates the results of analyses of Cladocera, pollen, plant macrofossil, lithological and radiocarbon data
recovered from a mire located in the Rawka River valley in central Poland. These studies permit to recognise the development
of hydrology phases in Kopanicha mire and give insight into Holocene fluvial dynamics of the system; radiocarbon dating partly
allowed da-ting of the patterns of Holocene valley floor development of the Rawka River. The Kopanicha mire was formed during
the Atlantic period. At that time, an oxbow lake formed, becoming a mire during the Subboreal and possibly Subatlantic periods.
The high sensitivity of the oxbow lakes, fens, fauna, and flora remains to climate variations - especially to changes in water
level connected with the ag-gradation-erosion cycle of rivers - allows the reconstruction of the palaeoecological changes
that oc-curred in the mire. The frequency and timing of hydroclimatic oscillations at Kopanicha show strong similarities to
records from other sites in Poland. Changes in Cladocera frequency and plant assem-blages were mostly influenced by the Rawka
River which controlled the hydrological regime of the mire. The main factors controlling the presence of Cladocera taxa were
the water level and the pres-ence of favourable conditions in the mire (e.g. pH, vegetation). Most of the changes occurred
in re-sponse to climate changes, but some of them were connected with local factors. 相似文献
39.
S.?WurzEmail author P.?Van?Peer N.?le?Roux S.?Gardner H.?J.?Deacon 《African Archaeological Review》2005,22(1):1-24
The technology of the end products i.e. blades and points in Late Pleistocene stone artefact assemblages from Klasies River, South Africa, and the Nile Valley, Egypt, are compared. The comparison includes univariate and multivariate analysis of metrical attributes enhanced by graphical biplot displays. The end products in these assemblages are either dominantly points or blades and this is related to the core reduction strategy adopted. The MSA 11 from Klasies River and the Nubian Complex industry from the Nile Valley are point industries made in the Levallois tradition, while the MSA 1 from Klasies River and the Taramsan from the Nile Valley may be non-Levallois or adapted Levallois blade industries. Dating of the assemblages shows the changes between dominant core reduction strategies are sequential and time restricted in both South and North Africa. It is concluded that variability of the same kind occurs in Middle Stone Age and Middle Palaeolithic assemblages south and north of the Sahara in the early Late Pleistocene.Dans cet article, les technologies des produits recherchés, des lames et des pointes, pour certains ensembles lithiques de Klasies River, Afrique du Sud et la Vallée du Nil, Egypte, sont comparées. Cette comparaison implique des analyses univariées et multivariées de variables métriques biplot. Les produits recherchés sont bien des pointes que des lames, selon les stratégies dexploitation adoptées. Le MSA II de Klasies River et le Complexe nubien de la Vallée du Nil sont des industries à pointes issues de la tradition Levallois. Par contre, le MSA I de Klasies River et le Taramsien de la Vallée du Nil évoquent une technologie de production non-Levallois ou Levallois modifiée. Les éléments de datation disponibles indiquent que les changements dans la prépondérance des stratégies dexploitation senchaînent dans une séquence chronologique bien identifiable, aussibien dans lAfrique du Sud que lAfrique du Nord. On arrive à la conclusion quune variabilité du même caractère est attestée dans les ensembles du Middle Stone Age et du Paléolithique moyen au sud et au nord du Sahara, pendant le Pléistocène supérieur ancien. 相似文献
40.
R.?N.?E.?BartonEmail author A.?Bouzouggar S.?N.?Collcutt R.?Gale T.?F.?G.?Higham L.?T.?Humphrey S.?Parfitt E.?Rhodes C.?B.?Stringer F.?Malek 《African Archaeological Review》2005,22(2):77-100
New work at Kehf el Hammar Cave provides the first well-dated palaeoenvironmental sequence for the Late Upper Palaeolithic in this region of the northwest Maghreb. The archaeological layers are dated via a combination of AMS radiocarbon and luminescence dating methods. The sequence contains charcoal-rich occupation layers with faunal, human and lithic finds. Local vegetational patterns are reconstructed on the basis of preliminary analysis of the charcoal evidence. Using standard calibration curves the AMS radiocarbon dates are compared with proxy evidence for climatic change from sea core records in the Alborán Sea. These appear to show that the Late Upper Palaeolithic occupation of the region coincides closely with Heinrich Event 1, a period marked by intense aridification and dating to ca. 16,700–17,250 calendar years ago.Les nouvelles recherches dans la grotte de Kehf el Hammar ont permis d’obtenir la première séquence paléoenevironnementale bien datée du Paléolithique supérieur tardif au Nord Ouest du Maghreb. En effet, les niveaux archéologiques ont été datés par le radiocarbone par accélérateur (AMS) et des méthodes radiométriques basées sur la luminescence. En revanche, les paléoenvironnements végétaux ont été partiellement reconstitués à base des premières analyses des charbons de bois. Les dates AMS calibrées ont été comparées aux données climatiques issues des carottes marines dans la mer Alborán. Ainsi, les occupations humaines du Paléolithique supérieur tardif dans la région ont sensiblement coïncidé avec l’événement climatique Heinrich 1. Celui-ci correspond à une période qui a été marquée par une aridification intense entre 16.700 et 17.250 ans (cal.). 相似文献