Artigos de revistas: "Trace fossils Australia, Central"

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Walter, M. R., R. Elphinstone e G. R. Heys. "Proterozoic and Early Cambrian trace fossils from the Amadeus and Georgina Basins, central Australia". Alcheringa: An Australasian Journal of Palaeontology 13, n.º 3 (janeiro de 1989): 209–56. http://dx.doi.org/10.1080/03115518908527821.

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McMahon, William J., Alexander G. Liu, Benjamin H. Tindal e Maarten G. Kleinhans. "Ediacaran life close to land: Coastal and shoreface habitats of the Ediacaran macrobiota, the Central Flinders Ranges, South Australia". Journal of Sedimentary Research 90, n.º 11 (30 de novembro de 2020): 1463–99. http://dx.doi.org/10.2110/jsr.2020.029.

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ABSTRACT The Rawnsley Quartzite of South Australia hosts some of the world's most diverse Ediacaran macrofossil assemblages, with many of the constituent taxa interpreted as early representatives of metazoan clades. Globally, a link has been recognized between the taxonomic composition of individual Ediacaran bedding-plane assemblages and specific sedimentary facies. Thorough characterization of fossil-bearing facies is thus of fundamental importance for reconstructing the precise environments and ecosystems in which early animals thrived and radiated, and distinguishing between environmental and evolutionary controls on taxon distribution. This study refines the paleoenvironmental interpretations of the Rawnsley Quartzite (Ediacara Member and upper Rawnsley Quartzite). Our analysis suggests that previously inferred water depths for fossil-bearing facies are overestimations. In the central regions of the outcrop belt, rather than shelf and submarine canyon environments below maximum (storm-weather) wave base, and offshore environments between effective (fair-weather) and maximum wave base, the succession is interpreted to reflect the vertical superposition and lateral juxtaposition of unfossiliferous non-marine environments with fossil-bearing coastal and shoreface settings. Facies comprise: 1, 2) amalgamated channelized and cross-bedded sandstone (major and minor tidally influenced river and estuarine channels, respectively), 3) ripple cross-laminated heterolithic sandstone (intertidal mixed-flat), 4) silty-sandstone (possible lagoon), 5) planar-stratified sandstone (lower shoreface), 6) oscillation-ripple facies (middle shoreface), 7) multi-directed trough- and planar-cross-stratified sandstone (upper shoreface), 8) ripple cross-laminated, planar-stratified rippled sandstone (foreshore), 9) adhered sandstone (backshore), and 10) planar-stratified and cross-stratified sandstone with ripple cross-lamination (distributary channels). Surface trace fossils in the foreshore facies represent the earliest known evidence of mobile organisms in intermittently emergent environments. All facies containing fossils of the Ediacaran macrobiota remain definitively marine. Our revised shoreface and coastal framework creates greater overlap between this classic “White Sea” biotic assemblage and those of younger, relatively depauperate “Nama”-type biotic assemblages located in Namibia. Such overlap lends support to the possibility that the apparent biotic turnover between these assemblages may reflect a genuine evolutionary signal, rather than the environmental exclusion of particular taxa.

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Barnes, Richard W., e Robert S. Hill. "Ceratopetalum fruits from Australian cainozoic sediments and their significance for petal evolution in the genus". Australian Systematic Botany 12, n.º 5 (1999): 635. http://dx.doi.org/10.1071/sb98014.

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Ceratopetalum Sm. fruits are characterised by 4–6 enlarged woody sepals radiating from a central disk, a semi-inferior ovary, anthers between and above each sepal and three-trace sepal venation with a prominent intra-sepal vein. Two new species of Ceratopetalum are described from fruits extracted from Australian Cainozoic sediments, C. westermannii and C. maslinensis. The presence of Ceratopetalum in Middle Eocene Maslin Bay sediments, South Australia, indicates a more widespread geographic distribution for the genus during the Cenozoic. Petally is present in one extant and two fossil species and probably represents the ancestral state despite apetally in the oldest known fossil. Petals have probably been secondarily lost in response to fruit specialisation or a change in pollinator vector.

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Cramwinckel, Margot J., Lineke Woelders, Emiel P. Huurdeman, Francien Peterse, Stephen J. Gallagher, Jörg Pross, Catherine E. Burgess, Gert-Jan Reichart, Appy Sluijs e Peter K. Bijl. "Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: inferences from dinoflagellate cysts and biomarker paleothermometry". Climate of the Past 16, n.º 5 (1 de setembro de 2020): 1667–89. http://dx.doi.org/10.5194/cp-16-1667-2020.

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Abstract. Global climate cooled from the early Eocene hothouse (∼52–50 Ma) to the latest Eocene (∼34 Ma). At the same time, the tectonic evolution of the Southern Ocean was characterized by the opening and deepening of circum-Antarctic gateways, which affected both surface- and deep-ocean circulation. The Tasmanian Gateway played a key role in regulating ocean throughflow between Australia and Antarctica. Southern Ocean surface currents through and around the Tasmanian Gateway have left recognizable tracers in the spatiotemporal distribution of plankton fossils, including organic-walled dinoflagellate cysts. This spatiotemporal distribution depends on both the physicochemical properties of the water masses and the path of surface-ocean currents. The extent to which climate and tectonics have influenced the distribution and composition of surface currents and thus fossil assemblages has, however, remained unclear. In particular, the contribution of climate change to oceanographic changes, superimposed on long-term and gradual changes induced by tectonics, is still poorly understood. To disentangle the effects of tectonism and climate in the southwest Pacific Ocean, we target a climatic deviation from the long-term Eocene cooling trend: the Middle Eocene Climatic Optimum (MECO; ∼40 Ma). This 500 kyr phase of global warming was unrelated to regional tectonism, and thus provides a test case to investigate the ocean's physicochemical response to climate change alone. We reconstruct changes in surface-water circulation and temperature in and around the Tasmanian Gateway during the MECO through new palynological and organic geochemical records from the central Tasmanian Gateway (Ocean Drilling Program Site 1170), the Otway Basin (southeastern Australia), and the Hampden Beach section (New Zealand). Our results confirm that dinocyst communities track specific surface-ocean currents, yet the variability within the communities can be driven by superimposed temperature change. Together with published results from the east of the Tasmanian Gateway, our new results suggest a shift in surface-ocean circulation during the peak of MECO warmth. Simultaneous with high sea-surface temperatures in the Tasmanian Gateway area, pollen assemblages indicate warm temperate rainforests with paratropical elements along the southeastern margin of Australia. Finally, based on new age constraints, we suggest that a regional southeast Australian transgression might have been coincident with the MECO.

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Evans, Scott D., Ian V. Hughes, James G. Gehling e Mary L. Droser. "Discovery of the oldest bilaterian from the Ediacaran of South Australia". Proceedings of the National Academy of Sciences 117, n.º 14 (23 de março de 2020): 7845–50. http://dx.doi.org/10.1073/pnas.2001045117.

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Analysis of modern animals and Ediacaran trace fossils predicts that the oldest bilaterians were simple and small. Such organisms would be difficult to recognize in the fossil record, but should have been part of the Ediacara Biota, the earliest preserved macroscopic, complex animal communities. Here, we describeIkaria wariootiagen. et sp. nov. from the Ediacara Member, South Australia, a small, simple organism with anterior/posterior differentiation. We find that the size and morphology ofIkariamatch predictions for the progenitor of the trace fossilHelminthoidichnites—indicative of mobility and sediment displacement. In the Ediacara Member,Helminthoidichnitesoccurs stratigraphically below classic Ediacara body fossils. Together, these suggest thatIkariarepresents one of the oldest total group bilaterians identified from South Australia, with little deviation from the characters predicted for their last common ancestor. Further, these trace fossils persist into the Phanerozoic, providing a critical link between Ediacaran and Cambrian animals.

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TRAVOUILLON, KENNY J., BRUNO F. SIMÕES, ROBERTO PORTELA MIGUEZ, SELINA BRACE, PHILIPPA BREWER, DAVID STEMMER, GILBERT J. PRICE, JONATHAN CRAMB e JULIEN LOUYS. "Hidden in plain sight: reassessment of the pig-footed bandicoot, Chaeropus ecaudatus (Peramelemorphia, Chaeropodidae), with a description of a new species from central australia, and use of the fossil record to trace its past distribution". Zootaxa 4566, n.º 1 (13 de março de 2019): 1. http://dx.doi.org/10.11646/zootaxa.4566.1.1.

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The Pig-footed Bandicoot, Chaeropus ecaudatus, an extinct arid-adapted bandicoot, was named in 1838 based on a specimen without a tail from the Murray River in New South Wales. Two additional species were later named, C. castanotis and C. occidentalis, which have since been synonymised with C. ecaudatus. Taxonomic research on the genus is rather difficult because of the limited material available for study. Aside from the types of C. castanotis and C. occidentalis housed at the Natural History Museum in London, and the type of C. ecaudatus at the Australian Museum in Sydney, there are fewer than 30 other modern specimens in other collections scattered around the world. Examining skeletal and dental characters for several specimens, and using a combination of traditional morphology, morphometrics, palaeontology and molecular phylogenetics, we have identified two distinct species, C. ecaudatus and C. yirratji sp. nov., with C. ecaudatus having two distinct subspecies, C. e. ecaudatus and C. e. occidentalis. We use palaeontological data to reconstruct the pre-European distribution of the two species, and review the ecological information known about these extinct taxa.

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Sappenfield, Aaron, Mary L. Droser e James G. Gehling. "Problematica, trace fossils, and tubes within the Ediacara Member (South Australia): redefining the ediacaran trace fossil record one tube at a time". Journal of Paleontology 85, n.º 2 (março de 2011): 256–65. http://dx.doi.org/10.1666/10-068.1.

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Ediacaran trace fossils are becoming an increasingly less common component of the total Precambrian fossil record as structures previously interpreted as trace fossils are reinterpreted as body fossils by utilizing qualitative criteria. Two morphotypes, Form E and Form F of Glaessner (1969), interpreted as trace fossils from the Ediacara Member of the Rawnsley Quartzite in South Australia are shown here to be body fossils of a single, previously unidentified tubular constructional morphology formally described herein as Somatohelix sinuosus n. gen. n. sp. S. sinuosus is 2-7 mm wide and 3-14 cm long and is preserved as sinusoidal casts and molds on the base of beds. Well-preserved examples of this fossil preserve distinct body fossil traits such as folding, current alignment, and potential attachment to holdfasts. Nearly 200 specimens of this fossil have been documented from reconstructed bedding surfaces within the Ediacara Member. When viewed in isolated hand sample, many of these specimens resemble ichnofossils. However, the ability to view large quantities of reassembled and successive bedding surfaces within specific outcrops of the Ediacara Member provides a new perspective, revealing that isolated specimens of rectilinear grooves on bed bases are not trace fossils but are poorly preserved specimens of S. sinuosus. Variation in the quality and style of preservation of S. sinuosus on a single surface and the few distinct characteristics preserved within this relatively indistinct fossil also provides the necessary data required to define a taphonomic gradient for this fossil. Armed with this information, structures which have been problematic in the past can now be confidently identified as S. sinuosus based on morphological criteria. This suggests that the original organism that produced this fossil was a widespread and abundant component of the Ediacaran ecosystem.

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Kakuwa, Yoshitaka, e James D. Floyd. "Trace fossils in Ordovician radiolarian chert successions in the Southern Uplands, Scotland". Earth and Environmental Science Transactions of the Royal Society of Edinburgh 107, n.º 1 (março de 2016): 13–22. http://dx.doi.org/10.1017/s1755691017000044.

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ABSTRACTRadiolarian chert and associated siliceous claystone in the Southern Uplands of Scotland are examined, in order to study the Great Ordovician Biodiversification Event of benthic animals on the pelagic ocean bottom. Trace fossils which are uncommon, but convincing, are found in the grey chert and siliceous claystone of Gripps Cleuch. These observations constitute firm evidence that large benthic animals which could leave visible trace fossils had colonised the Iapetan Ocean by the late Middle Ordovician, confirming previous studies from Australia for Panthalassa, the other huge ocean. Red chert is, however, a poor recorder of trace fossils, probably because the highly oxidising environment breaks down organic matter, both inhibiting high-density activity of large benthic animals and removing clear traces of benthic animal life.

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Wnuk, Christopher, e John O. Maberry. "Enigmatic eight-meter trace fossils in the Lower Pennsylvanian Lee Sandstone, central Appalachian Basin, Tennessee". Journal of Paleontology 64, n.º 3 (maio de 1990): 440–50. http://dx.doi.org/10.1017/s0022336000018679.

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Enigmatic tubular trace fossils up to eight meters long occur in the Lower Pennsylvanian Middlesboro Member of the Lee Formation. Two morphotypes occur: type 1 trace fossils are plain, smooth, vertical, nonbranching, parallel-walled, tubular structures; type 2 trace fossils branch, have walls with faint vertical striations, regularly or irregularly spaced nodes, and funnel-shaped terminations. Sandstone casts filling type 2 structures have helical spiral morphology, and, in rare individuals, faint meniscate fills have been observed. Both trace-fossil morphotypes have poorly cemented wall linings containing framboidal pyrite, amorphous carbon, quartz sand, and poorly preserved fecal material.The trace fossils occur in a massive, structureless, channel-form sandstone, originating at the contact between a channel lag and the overlying massive fill. The stratigraphic sequence is interpreted to represent a barrier island transgressing an estuarine facies. A tidal inlet within the barrier facies scoured into the underlying estuarine sediments. Subsequent rapid filling of the inlet led to the deposition of the massive sandstone.Origin of these structures is uncertain. The preponderance of evidence favors the hypothesis that the structures are escape burrows of animals that had colonized, or were concentrated in, the lag and were suddenly buried by the deposition of the massive sand. However, no likely burrower has been identified, and several characteristics of the structures and the enclosing sediments indicate that they may be completely inorganic in origin.

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Gibson, Gail G. "Trace fossils from Late Precambrian Carolina slate belt, south-central North Carolina". Journal of Paleontology 63, n.º 1 (janeiro de 1989): 1–10. http://dx.doi.org/10.1017/s0022336000040889.

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The volcanosedimentary sequence of the Carolina slate belt in south-central North Carolina was long thought to be unfossiliferous; however, the 5,484–7,315 meters of dominantly evenly bedded siltstones and mudstones have recently yielded body fossils of the late Precambrian Ediacarian fauna and a Middle Cambrian trilobite assemblage. Ongoing stratigraphic studies in the Carolina slate belt of southern North Carolina have now revealed trace fossils representing the ichnotaxa Gordia arcuata?, ?Helminthopsis sp., Monocraterion sp., Neonerites biserialis, N. uniserialis, ?Neonerites sp., Planolites beverlyensis, P. montanus, ?Planolites sp., Syringomorpha nilssoni?,? Tomaculum sp., Torrowangea sp., and three additional indeterminate ichnogenera. These trace fossils, lacking ornamentation and complex patterns, compare favorably with ichnofossil assemblages from Late Proterozoic stratigraphic sequences (Ichnofossil Zone I) elsewhere and support the late Precambrian age interpretation for the Carolina slate belt in south-central North Carolina.

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Smelror, Morten, e Dirk Knaust. "Trace fossils and palynomorphs in Holocene calcareous concretions from Lake Selbusjøen, Mid-Norway: Post-glacial environmental records". Holocene 31, n.º 5 (17 de janeiro de 2021): 732–45. http://dx.doi.org/10.1177/0959683620988046.

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Trace fossils and palynomorphs are recorded for the first time in Holocene calcareous concretions from Lake Selbusjøen, Central Norway. The described trace fossils can be assigned to the Mermia ichnofacies, characterizing lake deposits with good oxygenation and low depositional energy. The predominance of simple grazing trails and shallow burrows (e.g. Cochlichnus, Helminthoidichnites and Treptichnus) in silty and sandy concretions possibly represent relatively low-energy sublittoral parts of the lake, while the occurrence of Vagorichnus and Arenicolites in sandy substrate points to littoral and shallow sublittoral areas with moderate depositional energy. The trace fossils and palynomorph assemblages from Lake Selbusjøen appear to relate to periods of climatic warming during Pre-Boreal times, and possibly also Atlantic times.

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Camens, Aaron B., Stephen P. Carey e Lee J. Arnold. "Vertebrate Trace Fossils from the Late Pleistocene of Kangaroo Island, South Australia". Ichnos 25, n.º 2-3 (11 de julho de 2017): 232–51. http://dx.doi.org/10.1080/10420940.2017.1337633.

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KRAUSE, J. MARCELO, THOMAS M. BOWN, EDUARDO S. BELLOSI e JORGE F. GENISE. "TRACE FOSSILS OF CICADAS IN THE CENOZOIC OF CENTRAL PATAGONIA, ARGENTINA". Palaeontology 51, n.º 2 (março de 2008): 405–18. http://dx.doi.org/10.1111/j.1475-4983.2008.00753.x.

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Earp, Clem. "Early Devonian fossils from the Broadford Formation, central Victoria". Proceedings of the Royal Society of Victoria 127, n.º 2 (2015): 7. http://dx.doi.org/10.1071/rs15014.

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The Broadford Formation of central Victoria, Australia, hitherto lacked an identifiable fossil record but has, nevertheless, recently been considered to be wholly Silurian. Shelly fossil localities below and within the Broadford Formation reported in this study have yielded Boucotia australis and other brachiopods, indicating that much of the formation has a maximum age of Early Devonian.

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Kakuwa, Y., e J. Webb. "Evolution of Cambrian to Ordovician trace fossils in pelagic deep-sea chert, Australia". Australian Journal of Earth Sciences 57, n.º 5 (julho de 2010): 615–25. http://dx.doi.org/10.1080/08120099.2010.494766.

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Shi, G. R., Yi-Ming Gong e A. Potter. "Late Silurian trace fossils from the Melbourne Formation, Studley Park, Victoria, southeastern Australia". Alcheringa: An Australasian Journal of Palaeontology 33, n.º 3 (setembro de 2009): 185–209. http://dx.doi.org/10.1080/03115510902844301.

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Gangidine, Andrew, Malcolm R. Walter, Jeff R. Havig, Clive Jones, Daniel M. Sturmer e Andrew D. Czaja. "Trace Element Concentrations Associated with Mid-Paleozoic Microfossils as Biosignatures to Aid in the Search for Life". Life 11, n.º 2 (13 de fevereiro de 2021): 142. http://dx.doi.org/10.3390/life11020142.

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Identifying microbial fossils in the rock record is a difficult task because they are often simple in morphology and can be mimicked by non-biological structures. Biosignatures are essential for identifying putative fossils as being definitively biological in origin, but are often lacking due to geologic effects which can obscure or erase such signs. As such, there is a need for robust biosignature identification techniques. Here we show new evidence for the application of trace elements as biosignatures in microfossils. We found elevated concentrations of magnesium, aluminum, manganese, iron, and strontium colocalized with carbon and sulfur in microfossils from Drummond Basin, a mid-Paleozoic hot spring deposit in Australia. Our results also suggest that trace element sequestrations from modern hot spring deposits persist through substantial host rock alteration. Because some of the oldest fossils on Earth are found in hot spring deposits and ancient hot spring deposits are also thought to occur on Mars, this biosignature technique may be utilized as a valuable tool to aid in the search for extraterrestrial life.

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Bengtson, Stefan, Birger Rasmussen, Jian-Wei Zi, Ian R. Fletcher, James G. Gehling e Bruce Runnegar. "Eocene animal trace fossils in 1.7-billion-year-old metaquartzites". Proceedings of the National Academy of Sciences 118, n.º 40 (27 de setembro de 2021): e2105707118. http://dx.doi.org/10.1073/pnas.2105707118.

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The Paleoproterozoic (1.7 Ga [billion years ago]) metasedimentary rocks of the Mount Barren Group in southwestern Australia contain burrows indistinguishable from ichnogenera Thalassinoides, Ophiomorpha, Teichichnus, and Taenidium, known from firmgrounds and softgrounds. The metamorphic fabric in the host rock is largely retained, and because the most resilient rocks in the sequence, the metaquartzites, are too hard for animal burrowing, the trace fossils have been interpreted as predating the last metamorphic event in the region. Since this event is dated at 1.2 Ga, this would bestow advanced animals an anomalously early age. We have studied the field relationships, petrographic fabric, and geochronology of the rocks and demonstrate that the burrowing took place during an Eocene transgression over a weathered regolith. At this time, the metaquartzites of the inundated surface had been weathered to friable sandstones or loose sands (arenized), allowing for animal burrowing. Subsequent to this event, there was a resilicification of the quartzites, filling the pore space with syntaxial quartz cement forming silcretes. Where the sand grains had not been dislocated during weathering, the metamorphic fabric was seemingly restored, and the rocks again assumed the appearance of hard metaquartzites impenetrable to animal burrowing.

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Sarkar, Subir, Santanu Banerjee e Pradip K. Bose. "Trace fossils in the Mesoproterozoic Koldaha Shale, Central India, and their implications". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1996, n.º 7 (1 de julho de 1996): 425–38. http://dx.doi.org/10.1127/njgpm/1996/1996/425.

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Louys, Julien, Yahdi Zaim, Yan Rizal, Gilbert J. Price, Aswan Aswan, Mika Rizki Puspaningrum, Holly Smith e Agus Tri Hascaryo. "Palaeontological surveys in Central Sumatra and Bangka". Berita Sedimentologi 47, n.º 3 (28 de dezembro de 2021): 50–56. http://dx.doi.org/10.51835/bsed.2021.47.3.358.

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We report on results from surveys undertaken in Sumatra during 2018 and 2019. The surveys had three objectives: (1) to examine, sample, and record the extensive Quaternary fossil deposits from caves in West Sumatra; (2) determine the potential for fluvial deposits in Riau and Jambi provinces; and (3) relocate the fossil proboscidean remains reported from Bangka Island. Our surveys produced several significant results. We mapped three important Padang Highland caves, Ngalau Lida Ajer, Ngalau Sampit, and Ngalau Gupin, locating and sampling the main fossil deposits in each, as well as recording additional caves in the region. Our surveys of the fluvial systems in central-west Sumatra did not reveal any vertebrate Pleistocene deposits but did yield Mio-Pliocene trace fossils. Finally, we relocated elephant fossils from Bangka, but no in situ vertebrate remains could be found. These finds add important new data to the geological history of Sumatra.

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Ezeh, Sunny C., Wilfred A. Mode e Berti M. Ozumba. "Characteristic trace fossils from Miocene brackish-water deposits in the Niger Delta, Nigeria". Geologos 24, n.º 2 (1 de agosto de 2018): 111–25. http://dx.doi.org/10.2478/logos-2018-0011.

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Abstract Miocene deposits in the eastern portion of the Greater Ughelli, Central Swamp and Coastal Swamp depobelts contain well-developed brackish-water trace fossil assemblages. Twelve ichnogenera have been identified, namely: Asterosoma, Bergaueria, Chondrites, Gyrolithes, Thalassinoides, Lockeia, Palaeophycus, ?Conichnus, Planolites, Siphonichnus, Skolithos and Diplocraterion. In addition, common non-descript, passively filled burrows and fugichnia (escape structures) have also been observed. The above-mentioned ichnogenera and associated non-descript structures can be arranged into six distinct and recurring ichnoassociations within the Greater Ughelli, Central Swamp and Coastal Swamp depobelts. Each ichnoassociation is comprised of a group of trace fossils which collectively reflect specific environmental conditions during deposition of these Miocene strata. All trace fossil assemblages illustrate deposition in nearshore, restricted settings. Ichnological and sedimentological criteria which may be utilized to recognise brackish-water deposits are discussed and illustrated in pictures of the cores studied.

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Shahkarami, Setareh, M. Gabriela Mángano e Luis A. Buatois. "Ichnostratigraphy of the Ediacaran-Cambrian boundary: new insights on lower Cambrian biozonations from the Soltanieh Formation of northern Iran". Journal of Paleontology 91, n.º 6 (12 de setembro de 2017): 1178–98. http://dx.doi.org/10.1017/jpa.2017.72.

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AbstractStrata in the Central Alborz Mountains, northern Iran, are interpreted to show continuous sedimentation from Ediacaran through Cambrian times. The Soltanieh Formation consists of five members: Lower Dolomite, Lower Shale, Middle Dolomite, Upper Shale and Upper Dolomite members. The clastic units (Lower and Upper Shale members) represent sedimentation in distal marine settings, ranging from the shelf to offshore, and contain abundant trace fossils of biostratigraphic utility. Four ichnozones have been recognized. Ichnozone 1, containingHelminthoidichnites tenuis,Helminthopsis tenuis, andCochlichnus anguineus, is early Fortunian based on small shelly fossils, and is interpreted as a distal expression of theTreptichnus pedumzone. Ichnozone 2, comprising the first occurrence ofT.pedum, is middle Fortunian, and is best regarded as the upper half of theTreptichnus pedumZone. Ichnozone 3 is late Fortunian–Cambrian Age 2, characterized by a sudden change in abundance and complexity of trace fossils. Main elements in this ichnozone includeCruziana problematica,Curvolithusisp., Phycodesisp.,Treptichnus pedum,Treptichnus pollardi, andTreptichnusisp. Ichnozone 4 is of Cambrian Age 2–Age 3 and marked by the first appearances ofPsammichnites gigas,Rusophycus avalonensis, andDidymaulichnus miettensis. Integration of trace fossils with small shelly fossils suggests that the Ediacaran–Cambrian boundary should be placed at the base of the Soltanieh Formation or within the Lower Dolomite Member. The delayed appearance ofT.pedumand the low ichnodiversity in the Lower Shale and lower interval of the Upper Shale reflect limited colonization of settings below storm wave base during the early Fortunian.

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Hussein, Mohammad Ali, Mohammad Alqudah e Olaf G. Podlaha. "Ichnofabrics of Eocene oil shales from central Jordan and their use for paleoenvironmental reconstructions". GeoArabia 19, n.º 1 (1 de janeiro de 2014): 85–112. http://dx.doi.org/10.2113/geoarabia190185.

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ABSTRACT The study of trace fossils is widely used in facies interpretation. It provides a crucial tool for reconstructing depositional paleoenvironments when used in combination with other sedimentological and paleontological proxies. Here we present the first detailed study of Eocene trace fossils from Jordan. Two sections of Early to Middle Eocene age, with a total thickness of 478.7 m, from central Jordan were cored and investigated. The results of individually occurring (isolated) or co-occurring (combined) ichnofabrics and bioturbation levels, in combination with results from biostratigraphic and geochemical studies, were used for stratigraphic and paleoenvironmental reconstructions. The bioturbation index (BI) was used to classify the burrowing density versus the preservation of the original sedimentary structures. The two cores show highly variable grades of bioturbation with BI ranging from 0 to 6. Four ichnogenera were identified: Thalassinoides, Chondrites, Teichichnus and Zoophycos. Both the ichnofabrics and the variations of the BI suggest a shallow, highly dynamic depositional system with rapid changes of water depth and degree of bottom-water oxygenation.

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Miller, Molly F., e James W. Collinson. "Trace Fossils from Permian and Triassic Sandy Braided Stream Deposits, Central Transantarctic Mountains". PALAIOS 9, n.º 6 (dezembro de 1994): 605. http://dx.doi.org/10.2307/3515131.

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KOTAKE, NOBUHIRO. "Taphonomy of the Trace Fossils in Bathyal Deposits Distributing Boso Peninsula, Central Japan". Benthos research, n.º 35-36 (1989): 53–60. http://dx.doi.org/10.5179/benthos1981.1989.53.

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Voigt, Sebastian, e Dietrich Hoppe. "Mass Occurrence of Penetrative Trace Fossils in Triassic Lake Deposits (Kyrgyzstan, Central Asia)". Ichnos 17, n.º 1 (26 de fevereiro de 2010): 1–11. http://dx.doi.org/10.1080/10420940903358081.

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Pickerill, R. K. "Trace fossils from the Upper Ordovician (Caradoc) of the Berwyn Hills, Central Wales". Geological Journal 12, n.º 1 (30 de abril de 2007): 1–16. http://dx.doi.org/10.1002/gj.3350120101.

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Stachacz, Michał, Dirk Knaust e Michał Matysik. "Middle Triassic bivalve traces from central Europe (Muschelkalk, Anisian): overlooked burrows of a common ichnofabric". PalZ 96, n.º 1 (9 de novembro de 2021): 175–96. http://dx.doi.org/10.1007/s12542-021-00583-6.

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AbstractThe ichnotaxonomy, producers and ethology of the bivalve trace fossil Oravaichnium Plička and Uhrová, 1990 are revised, and the mode of formation is discussed. The ichnogenus is compared with other mollusc trace fossils such as Protovirgularia, Lockeia and Ptychoplasma, as well as the common, cosmopolitan trace fossils Planolites and Palaeophycus, which are morphologically similar to Oravaichnium. A lectotype of Oravaichnium hrabei Plička and Uhrová, 1990 is defined and illustrated. Oravaichnium carinatum isp. nov. from the Middle Triassic of Poland and Germany is described and interpreted as a bivalve burrow. It differs from the relatively rare O. hrabei by a carinate rather than subquadrate cross section. However, O. carinatum isp. nov. shows a great variation of morphology and transitional forms with O. hrabei are common. Similarly, transitional forms of Oravaichnium with other bivalve ichnogenera, especially Protovirgularia, also occur. The studied Triassic ichnoassemblage clearly indicates that bivalve burrows are much more common than previously believed and are represented by repichnia, fodinichnia and cubichnia. The occurrence of similar ichnofabrics containing Oravaichnium in other Triassic succession of the Germanic and Tethys basins and elsewhere suggests a much wider distribution than hitherto known. It is evident that bivalves, most likely nuculids, participated greatly in bioturbation, and the Middle Triassic infaunalisation is one of the most important steps in Phanerozoic evolution of ichnocoenoses.

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Briggs, Derek E. G., Molly F. Miller, John L. Isbell e Christian A. Sidor. "Permo-Triassic arthropod trace fossils from the Beardmore Glacier area, central Transantarctic Mountains, Antarctica". Antarctic Science 22, n.º 2 (18 de dezembro de 2009): 185–92. http://dx.doi.org/10.1017/s0954102009990708.

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AbstractPermian and Triassic lacustrine and fluvial-system deposits in the Beardmore Glacier area of the Transantarctic Mountains preserve a superb record of continental environments and evidence of life on extensive bedding plane exposures. They yielded the first invertebrate trackways reported from continental Permo-Triassic deposits of Antarctica, here assigned to the ichnogenera Diplichnites and Diplopodichnus, which were probably produced by myriapodous arthropods. A resting trace is compared to Orbiculichnus and interpreted as generated by a jumping insect. Plant life is represented by leaf impressions, fossil forests and peat, vertebrates by body and trace fossils, and invertebrate shallow infauna by near surface burrows. The small number and diversity of trackways recovered from the large bedding plane exposures suggest that trackway-producing arthropods were rare at these high southern palaeolatitudes.

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De Gibert, J. M., e A. A. Ekdale. "Trace fossil assemblages reflecting stressed environments in the Middle Jurassic Carmel Seaway of central Utah". Journal of Paleontology 73, n.º 4 (julho de 1999): 711–20. http://dx.doi.org/10.1017/s0022336000032522.

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The shallow-marine Carmel Formation (Middle Jurassic) in central Utah hosts low-diversity trace fossil assemblages, including Arenicolites, Chondrites, Gyrochorte, Lockeia, Planolites, Protovirgularia, Rosselia, Scalarituba, Skolithos, Taenidium, and Teichichnus. Non specialized ichnotaxa with a remarkably small burrow size dominate the assemblages. The amount of bioturbation is lower than expected in comparison with modern shallow-marine carbonate environments. These ichnological features also are significantly different from those of other Jurassic shallow-marine carbonates. The trace fossils represent an environmentally stressed benthic community in a marginal marine, restricted setting, with salinities above normal marine and with depletion of oxygen in pore waters.

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Pickerill, Ron K., Stephen K. Donovan e Harold L. Dixon. "The trace fossil Dactyloidites ottoi (Geinitz, 1849) from the Neogene August Town Formation of south-central Jamaica". Journal of Paleontology 67, n.º 6 (novembro de 1993): 1070–74. http://dx.doi.org/10.1017/s0022336000025415.

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Rosette-shaped problematica are relatively common structures in the Phanerozoic rock record. Historically, they have been accorded a variety of names and documented from various shallow to deep marine environments. Unfortunately, the detailed interpretation of many such structures as biogenic (trace fossils, medusoids, or other body fossils; see, for example, Häntzschel, 1970, 1975) or nonbiogenic (for example, Pickerill and Harris, 1979) in origin still remains to be resolved. However, a detailed analysis of one such structure by Fürsich and Bromley (1985), namely Dactyloidites Hall, 1886, convincingly demonstrated its biogenic origin. The distinctive morphology of Dactyloidites and its synonyms was interpreted by Fürsich and Bromley (1985) to result from successive probings of an essentially stationary deposit-feeding, worm-like organism, possibly possessing a proboscis, to produce a rosetted, vertical spreiten with a centrally located, vertical or subvertical shaft.

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Bryant, I. D., e R. K. Pickerill. "Lower Cambrian trace fossils from the Buen Formation of central North Greenland: preliminary observations". Rapport Grønlands Geologiske Undersøgelse 147 (1 de janeiro de 1990): 44–62. http://dx.doi.org/10.34194/rapggu.v147.8106.

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The trace fossils Cruziana cf. C. stromnessi (Trewin, 1976), Curvolithus Fritsch, 1908, Hormosiroidea Schaffer, 1928, Monomorphichnus cf. M. bilinearis Crimes, 1970, Monomorphichnus lineatus Crimes et al., 1977, cf. Palaeobullia Gotzinger & Becker, 1932, Palaeophycus tubularis Hall, 1847, Phycodes pedum Seilacher, 1955, Psammichnites Torell, 1870, Rusophycus Hall, 1852, Skolithos Haldeman, 1840 and cf. Zoophycos Massalongo, 1855 are recorded and briefly described from the Lower Cambrian Buen Formation, central North Greenland. Interbedded sandstones, siltstones and shales of the Buen Formation were deposited in a tide and storm-dominated shallow marine shelf environment. Ichnofaunal diversity is low in monolithologic cross-bedded sandstones, which characterise the basal portion of the sequence, and considerably higher in heterolithologic sandstones, siltstones and shales, which occur higher in the sequence.

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Bland, Benjamin H., e R. Goldring. "Teichichnus Seilacher 1955 and other trace fossils (Cambrian?) from the Charnian of Central England." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 195, n.º 1-3 (14 de fevereiro de 1995): 5–23. http://dx.doi.org/10.1127/njgpa/195/1995/5.

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Bolliger, Thomas. "Trace fossils and trackways in the Upper Freshwater Molasse of Central and Eastern Switzerland". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 214, n.º 3 (15 de dezembro de 1999): 519–36. http://dx.doi.org/10.1127/njgpa/214/1999/519.

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Sharma, Prakash, Flor Lucia De la Cruz e Jonathan Sultoon. "Finding winners in the hydrogen hype". APPEA Journal 62, n.º 2 (13 de maio de 2022): S67—S71. http://dx.doi.org/10.1071/aj21168.

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The global energy trade is set for its greatest transformation since the 1970s and the rise of OPEC (The Organization of the Petroleum Exporting Countries). Electrification is central to this as countries plough money into renewables to reduce emissions and enhance energy security. But electrification can take the world only so far. With higher carbon prices looming on the horizon, fossil fuel exporters and industrial sectors – as well as heavy-duty trucking, shipping and aviation – need alternatives to decarbonise. Most are looking to electricity-based fuels and feedstocks such as hydrogen, ammonia and methanol to replace hydrocarbons. This will revolutionise energy trade, with total trade declining by as much as 50% and virtually all remaining traded oil gas and coal being either completely decarbonised or backed by offsets. With 147 GWel (giga‐watts electrolyser capacity) in announced projects, green hydrogen produced from renewable electricity is ahead of the game. And while its export supply chains are complex, requiring conversion into a ‘product’ to allow delivery, there is no exploration risk as in oil and gas projects. Worldwide, national hydrogen roadmaps are being passed, with virtually all oil and gas companies, utilities and industrials backing at least one hydrogen project. Focus is now shifting to future sources of hydrogen supply. Lenders will be drawn to locations with a proven track record of exporting natural resources, suitable conditions for low-cost renewable electricity and the potential for large-scale carbon capture. A few countries already stand out, but none more so than Australia. Using our proprietary research, we will present a case study evaluating hydrogen supply options from Australia, Saudi Arabia and Canada – delivered into key markets like Japan for different applications. We will also assess when costs will fall across the value chain – production, midstream and downstream – and reach parity to incumbent fuels.

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MCILROY, DUNCAN, T. PETER CRIMES e JOHN C. PAULEY. "Fossils and matgrounds from the Neoproterozoic Longmyndian Supergroup, Shropshire, UK". Geological Magazine 142, n.º 4 (julho de 2005): 441–55. http://dx.doi.org/10.1017/s0016756805000555.

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Body and trace fossils of Ediacaran affinity are described from strata of the late Neoproterozoic Longmyndian Supergroup exposed near Church Stretton, Shropshire, UK. The almost spherical soft-bodied Ediacaran fossil Beltanelliformis brunsae Menner occurs rarely in the Burway Formation, but much smaller, simpler, discoidal structures are common in both the Burway and Synalds formations and are referred to Beltanelliformis minutae sp. nov. Similar discoidal structures, but with a distinct central depression, are included in Intrites punctatus Fedonkin and are common at several horizons. Two blocks with numerous examples of Medusinites aff. asteroides (Sprigg) Glaessner & Wade were recovered from the Burway Formation. The purported Ediacaran body fossil ‘Arumberia’ Glaessner & Walter is common at several horizons but its biogenicity is not accepted herein. ‘Arumberia’ is thus treated along with evidence for microbially bound sediment surfaces or matgrounds that have been suggested by several authors to be necessary for some types of Ediacaran preservation. The assemblage of simple trace and body fossils along with matgrounds is typical of latest Neoproterozoic time, though some elements range into the Phanerozoic.

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Smith, Roger M. H., e Thomas R. Mason. "Sedimentary Environments and Trace Fossils of Tertiary Oasis Deposits in the Central Namib Desert, Namibia". PALAIOS 13, n.º 6 (dezembro de 1998): 547. http://dx.doi.org/10.2307/3515346.

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Wilson, Mark A., e J. Keith Rigby. "Asteriacites lumbricalisvon schlotheim 1820: Ophiuroid trace fossils from the lower triassic thaynes formation, central Utah". Ichnos 7, n.º 1 (junho de 2000): 43–49. http://dx.doi.org/10.1080/10420940009380145.

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Uchman, Alfred, Nils-Martin Hanken e Richard Binns. "Ordovician Bathyal Trace Fossils From Metasiliciclastics in Central Norway and Their Sedimentological and Paleogeographical Implications". Ichnos 12, n.º 2 (abril de 2005): 105–33. http://dx.doi.org/10.1080/10420940590914534.

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Schroeder, Natalie I., John R. Paterson e Glenn A. Brock. "Eldonioids with associated trace fossils from the lower Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia". Journal of Paleontology 92, n.º 1 (janeiro de 2018): 80–86. http://dx.doi.org/10.1017/jpa.2018.6.

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AbstractRare specimens of eldonioids recovered from the lower Cambrian (Series 2, Stage 4) Emu Bay Shale (EBS) Konservat-Lagerstätte represent the first record of the group for the Cambrian of East Gondwana. The disc-shaped body of the EBS taxon bears fine concentric corrugations on the dorsal surface and, ventrally, a series of internal lobes that have primary and secondary bifurcations, as well as a coiled sac. It appears to be most similar toRotadiscusandPararotadiscusof the Cambrian Chengjiang and Kaili biotas of South China, respectively. While the structure of the internal lobes would indicate that this occurrence in the EBS represents a new taxon within the Rotadiscidae, lack of detail regarding the precise number of internal lobes and the condition of the circumoral tentacles warrants a more conservative approach in leaving the genus and species under open nomenclature. The EBS specimens also host trace fossils, including the remains of a burrow, which are generally lacking in the body-fossil-bearing layers of the Konservat-Lagerstätte interval. These traces appear to have been made by small organisms and are similar to traces associated with the discs ofPararotadiscus guizhouensis(Zhao and Zhu, 1994) from the Kaili Biota. The available taphonomic, paleoenvironmental, and ichnological evidence indicates that the EBS eldonioids are most likely vagrants that were transported or settled into the ‘preservational trap’ and subsequently exposed on the substrate for a brief period before burial, thereby allowing organisms to exploit their carcasses for nutrients or other purposes.

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Jago, J. B., e C. G. Gatehouse. "Early Cambrian trace fossils from the Kanmantoo Group at Red Creek, South Australia, and their stratigraphic significance". Australian Journal of Earth Sciences 54, n.º 4 (junho de 2007): 531–40. http://dx.doi.org/10.1080/08120090601078370.

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JENSEN, SÖREN, TEODORO PALACIOS e MONICA MARTÍ MUS. "Revised biochronology of the Lower Cambrian of the Central Iberian zone, southern Iberian massif, Spain". Geological Magazine 147, n.º 5 (12 de fevereiro de 2010): 690–703. http://dx.doi.org/10.1017/s0016756809990677.

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AbstractTrilobites from the upper unit of the Lower Cambrian Pusa Formation (south-central Spain) substantially antedate other Iberian trilobites, according to widely published correlation schemes, and arguably would be among the earliest trilobites globally. These trilobites, previously only briefly mentioned in texts, are here described and illustrated, and their biochronological context examined. The Pusa Formation trilobites are treated in open nomenclature but with suggested affinity to the genusAbadiella.They are associated with small shelly fossils, includingPelagiellasp., chancellorid spicules andCupithecasp., and unidentfied archaeocyathans. Trace fossils from the upper unit of the Pusa Formation, down-section of the trilobites, includeDactyloiditesisp. andRusophycusisp., the latter representing the lowest occurrence of this ichnogenus in the region. This biostratigraphical context demonstrates that the Pusa Formation trilobites are substantially younger than had traditionally been thought. In terms of Iberian regional stages they are Ovetian, not Corduban as previously thought. As a consequence of the data presented here, the definitions of Iberian Lower Cambrian regional stages are discussed and a substantially revised correlation between key Lower Cambrian strata of the Central Iberian and Ossa Morena zones is proposed.

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Izumi, Kentaro, e Kazuko Yoshizawa. "Star-shaped trace fossil and Phymatoderma from Neogene deep-sea deposits in central Japan: probable echiuran feeding and fecal traces". Journal of Paleontology 90, n.º 6 (11 de outubro de 2016): 1169–80. http://dx.doi.org/10.1017/jpa.2016.95.

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AbstractA co-occurrence of the ichnogenus Phymatoderma and a star-shaped horizontal trace fossil was discovered from Neogene deep-marine deposits (Misaki Formation, central Japan), and is described herein for the first time. Phymatoderma consists of a straight to slightly curved tunnel that shows first- or second-order branches. The tunnels are 5.30–27.25 mm in diameter and are filled with ellipsoidal pellets. The relatively well-preserved star-shaped trace fossil is a large horizontal structure (~18 cm×19 cm) that consists of at least 10 spokes with diameters ranging from 11.49–20.96 mm. As compared to modern analogous surface-feeding traces produced by abyssal echiuran worms and their burrow morphology, it is highly likely that the star-shaped trace fossil and Phymatoderma found from the Misaki Formation are feeding and fecal traces of ancient deep-sea echiurans, respectively. Difference in preservation potential between surface and subsurface traces may result in rare occurrence of star-shaped trace fossils as compared to Phymatoderma. Microscopic observation of the pelletal infill of Phymatoderma also reveals that the trace-maker fed on organic debris and microorganisms such as diatoms and radiolaria.

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Bjerstedt, Thomas W. "Trace Fossils Indicating Estuarine Deposystems for the Devonian-Mississippian Cloyd Conglomerate Member, Price Formation, Central Appalachians". PALAIOS 2, n.º 4 (1987): 339. http://dx.doi.org/10.2307/3514759.

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Palma-Ramírez, Arturo, Roberto Carlos Maldonado-Sarabia e Matthew R. Stimson. "Marginal marine trace fossils from the Cárdenas Formation (Maastrichtian), Rayón municipality, San Luis Potosí, Central Mexico". Revista Brasileira de Paleontologia 22, n.º 2 (31 de agosto de 2019): 89–96. http://dx.doi.org/10.4072/rbp.2019.2.01.

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Krapovickas, Verónica, Claudia A. Marsicano, Adriana C. Mancuso, Marcelo S. de la Fuente e Eduardo G. Ottone. "Tetrapod and invertebrate trace fossils from aeolian deposits of the lower Permian of central-western Argentina". Historical Biology 27, n.º 7 (22 de abril de 2014): 827–42. http://dx.doi.org/10.1080/08912963.2014.904857.

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Gradziński, Ryszard, e Alfred Uchman. "Trace fossils from interdune deposits—an example from the lower triassic aeolian Tumlin Sandstone, central Poland". Palaeogeography, Palaeoclimatology, Palaeoecology 108, n.º 1-2 (março de 1994): 121–38. http://dx.doi.org/10.1016/0031-0182(94)90025-6.

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Šimo, Vladimir, e Dušan Starek. "Analysis of the trace fossils from Paleogene formations of the Central Western Carpathian (Orava region) [abstract]." Geology, Geophysics & Environment 42, n.º 1 (2016): 126. http://dx.doi.org/10.7494/geol.2016.42.1.126.

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Trewin, N. H., e K. J. McNamara. "Arthropods invade the land: trace fossils and palaeoenvironments of the Tumblagooda Sandstone (?late Silurian) of Kalbarri, Western Australia". Transactions of the Royal Society of Edinburgh: Earth Sciences 85, n.º 3 (1994): 177–210. http://dx.doi.org/10.1017/s026359330000359x.

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AbstractThe trace fossils of the Tumblagooda Sandstone (?late Silurian) of Kalbarri, Western Australia are spectacular in their variety and preservation. They provide a unique insight into the activities of the early invaders of terrestrial environments, and reveal the presence of a diverse fauna dominated by arthropods. Within the Formation trace fossil assemblages can be related to fluvial, aeolian and marine sand-dominated environments. Two distinct and diverse ichnofaunas are recognised.The Heimdallia–Diplichnites Ichnofauna occurs in sandstones deposited in broad low sinuosity braided fluvial channels, between which were mixed aeolian and waterlain sandsheets, small aeolian dunes and flooded interdune and deflation hollows. Heimdallia is the major bioturbator, favouring shallow pools. Other burrows include Tumblagoodichnus (gen. nov.), Diplocraterion, Skolithos, Beaconites and Didymaulyponomos. Arthropod trackways (Diplichnites) occur on surfaces of waterlain sands and on foreset bedding of aeolian dunes, and represent some of the earliest reported terrestrial trackways. Other trackways include Paleohelcura and Protichnites, and the digging traces Selenichnites and Rusophycus are also present. At least ten types of arthropods are required to produce the observed traces. Myriapods, eurypterids, euthycarcinoids, xiphosurids and scorpionids are considered responsible for the trackway assemblage.The Skolithos–Diplocraterion Ichnofauna occurs at the top of the exposed section in sandstones that overlie a thick fluvial sequence containing few traces. The strata are considered to represent marine influence at a fluvial/marine transition. They show variable trough cross-bedding, complex planar cross-bedding with down-climbing sets, ripple lamination, and fining-up sequences with bioturbated tops. Traces are dominated by crowded Skolithos up to 1 m long, together with two forms of Diplocraterion. Daedalus and Lunatubichnus (gen. nov.) burrows occur in a few beds and Aulichnites trails cover some foreset surfaces of cross-bedding.The trace fossils and the sedimentology of the Tumblagooda Sandstone bear a remarkable similarity to those of the lower part of the Taylor Group of Antarctica, which is probably Devonian in age. It is suggested that the two represent a similar age, stratigraphy, and range of environments on the margins of Gondwana. Large unvegetated fluvial outwash plains with variable aeolian influence were essentially coastal in character and fluvial/marine transitions occur in sand-rich environments. The animals responsible for the traces inhabited coastal areas but many could survive outwith marine influence, and arthropods responsible for some types of Diplichnites trackways walked out of water.The rich diversity of trackways attributable to arthropods illustrate that the invasion of terrestrial environments by arthropods, particularly large forms, was well-established by the beginning of the Devonian. The basis of the food chain was algal and bacterial films which bound the surface sediment in freshwater pools.

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Schroeder, Natalie I., John R. Paterson e Glenn A. Brock. "RETRACTION—Eldonioids with associated trace fossils from the lower Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia". Journal of Paleontology 92, n.º 1 (janeiro de 2018): 114. http://dx.doi.org/10.1017/jpa.2017.156.

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