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EN
The island margin of Isla de Roatán is a unique place of outstanding scientific and didactic values, with one of the longestcoral reef and an astonishing fauna inhabiting the deep sea zones. The unique geomorphological conditions enable to perform shore-based submersible operations at great depths. In this paper a short report from our dive down to about 650 m is presented. Our preliminary dive was used to document a diverse faunal assemblage, which allowed for a better understanding of the fossil record.
EN
Three trackways attributable to the ichnospecies Bifurculapes laqueatus Hitchcock, 1858 found in Lower Jurassic rocks of the Newark Supergroup in northeastern North America are preserved in association with current lineations. Each trackway takes turns so that parts of the trackway parallel the current lineations. This parallelism is interpreted as evidence that the trackmakers were entrained in flowing water and had to change course due to the current. If this interpretation is correct, then morphological differences between B. laqueatus and terrestrial insect trackways could be explained by the trackmaker moving subaqueously. Further, B. laqueatus would constitute only the second insect trackway from this region to be recognized as being made subaqueously. From an ecological standpoint, the aquatic insects that made B. laqueatus were probably near the base of the local food chain, the apex predators of which were piscivorous theropod dinosaurs.
EN
The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils: Gyrochorte isp., Ophiomorpha nodosa Lundgren, 1891, Ophiomorpha isp., Phycodes cf. curvipalmatum (Pollard, 1981), ?Phycodes isp., Planolites cf. beverleyensis (Billings, 1862), Thalassinoides paradoxicus Woodward, 1830 and ?Thalassinoides isp. Moreover, interesting compound burrow systems, here referred to as Thalassinoides-Phycodes cf. palmatus and ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorte isp., Phycodes cf. flabellum (Miller and Dyer, 1878) and ?Treptichnus isp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropod Nerinea bicincta Bronn, 1836 and the bivalve Lima haidingeri Zittel, 1866 were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by Scupin (1912–1913). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha, Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte, Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha, Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes, Gyrochorte and ?Treptichnus). The assemblage of trace fossils is characteristic of the Skolithos ichnofacies and Cruziana ichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member sandstones by Leszczyński (2010). That author interpreted the Coniacian sandstones as bar and storm deposits laid down in a shallow epicontinental sea (mainly the foreshore-upper shoreface; up to the middle shoreface) under normal oxygenation and salinity, in soft substrate, above fair-weather wave base. The deposition of the Żerkowice Member sandstones is linked to a regression that started after uplift of the southeastern part of the North Sudetic Synclinorium.
EN
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.
EN
We describe a new echinoid assemblage, composed of specimens of Bolbaster sp., Cyclaster danicus (Schlüter, 1897), Diplodetus vistulensis (Kongiel, 1950) and Linthia? sp. in a distinctive phosphatic preservation, from the so-called Greensand, a marly glauconitic sandstone horizon at the base of the Danian succession in the Kazimierz Dolny area (central Poland). This assemblage presumably is of early Danian age, with Cyclaster danicus occurring in the lower Danian of Denmark and southern Sweden. The specimens are preserved as internal moulds, composed of phosphatised glauconitic sandstone, occasionally with some test material adhering. The genesis of these moulds involved the following steps: (1) infilling of tests of dead echinoids with glauconitic sand; (2) penetration of the infills by coelobiotic deposit-feeding organisms that produced burrows along the inner test surface; (3) early-diagenetic cementation of infills by calcium phosphate; and (4) exhumation and intraformational reworking of specimens, leading to abrasion, fragmentation and loss of test material in some individuals. Co-occurring are unphosphatised moulds of Echinocorys ex gr. depressa (von Eichwald, 1866) and Pseudogibbaster cf. depressus (Kongiel in Kongiel and Matwiejewówna, 1937), which may represent a younger (middle to late Danian) assemblage. Additionally, the presence of derived late Maastrichtian echinoids, e.g., Temnocidaris (Stereocidaris) ex gr. herthae (Schlüter, 1892), Pleurosalenia bonissenti (Cotteau, 1866) and Hemicara pomeranum Schlüter, 1902, is confirmed for the Greensand, based on new material and re- examination of previously recorded specimens. In summary, members of three echinoid assemblages of different age and preservation occur together in the Greensand. Our results are compatible with former interpretations of this unit as a condensed, transgressive lag with mixed faunas of different age and provenance. However, they are incompatible with the hypothesis that phosphatised Danian fossils preserved in the Greensand are derived from a facies equivalent, now gone, of the lower Danian Cerithium Limestone in eastern Denmark, because all moulds are composed of phosphatised glauconitic sandstone that is utterly different from the calcareous dinocyst-dominated, fine crystalline matrix of the Cerithium Limestone.
EN
The Middle Jurassic Kaladongar Formation, Patcham Island, Kachchh, western India, comprises of a 353 m-thick mixed siliciclastic-carbonate succession of asymmetrical shallowing and deepening upward sedimentary cycles. It is subdivided into five main facies i.e., micritic sandstone, allochemic sandstone, sandy allochem limestone, micritic mudrock, and sandy micrite along with shales and conglomerates. Eight trace fossil assemblages comprising 34 ichnogenera are defined, including the Asterosoma, Gyrochorte, Rhizocorallium, Thalassinoides, Planolites–Palaeophycus, Phycodes, Ophiomorpha, and Skolithos assemblages that reflect five depositional facies: offshore, transitional, lower, middle, and upper shoreface. The sedimentary packages and associated trace fossil assemblages are separated by various discontinuities, stratigraphic surfaces and stratigraphic boundaries within the succession of the Kaladongar Formation and reveal three phases of regression (RST-I, RST-II and RST-III) and three phases of transgression (TST-II, III and IV) within the 3rd order systems tracts developed in the slowly transgressing sea during the Bajocian-Bathonian time interval.
EN
The pascichnial trace fossil Bichordites kuzunensis isp. nov. occurs as an epichnial complex structure in early Oligocene prodelta sediments of the Thrace Basin in Gokceada Island, northwest Turkey. It displays characteristics of irregular echinoid burrows such as overall shape and a double meniscate filling with a chevron dorsal suture, in addition to the feature typical of the so far monospecific Bichordites Plaziat and Mahmoudi, 1988, that is a single central core around a single drainage tube. Its miniature size can be related to the small size of the tracemaker (ontogenic feature) or to its dwarfism in a stressed deltaic environment (palaeoecological feature). Its occurrence indicates a period of fully marine conditions during accumulation of the deltaic sediments of the Mezardere Formation.
EN
A complex trace fossil that requires a three-dimensional (3D) reconstruction is described and interpreted. The specimens studied are assigned to a new ichnospecies (Hillichnus agrioensis) of Hillichnus Bromley et al., 2003. Most of them are uncollectable and a compound iconotype was designed to characterise the new ichnospecies. The three-dimensional trace fossil has been recorded in marginal-marine deposits close to the top of the Agrio Formation (Lower Cretaceous of Neuquen Basin, Argentina). The new ichnospecies shows a different pattern of feeding than H. lobosensis Bromley et al., 2003, and records defaecation downward in the deeper preservational level (level 4). Feather-like structures (level 2) that typify the ichnogenus also record the activity of an inhalant siphon and indicate a retractile movement. The vertical shafts (level 1) are scarcely recorded. Aligned double rings also document the infaunal habit of the tellinid bivalves that are considered the most likely producers of the trace. It is clear that when only level 2 is exposed, in some cases this form can be assigned to Jamesonichnites heinbergi Dam 1990a consequently, this ichnospecies is interconnected with more than one ichnogenus. Vertical projections recorded in branches differ from the type ichnospecies H. lobosensis Bromley et al., 2003. The occurrence in marginal-marine facies is congruent with the record of Jamesonichnites but not common in the type species and similar to those more frequent in deep-sea deposits (e.g. Polykampton alpinum Ooster, 1869).
EN
The trace fossil Osculichnus labialis igen. et isp. nov. occurs as hypichnial pairs of uneven bilobate mounds in early Oligocene prodelta sediments of the Thrace Basin. Osculichnus is generally elliptical or crescentic in outline and has two lip-like lobes: a smaller and a larger one, which are separated by an undulate furrow. Herein, it is interpreted as a hunting trace (praedichnion) of a fish penetrating a surficial sand layer and into an underlying mud horizon. The fish hunted for small endobenthic bivalves and perhaps other invertebrates such as polychaetes. Penetration into surficial mud rather than sand resulted in poorly preserved variants of this trace fossil, whose median furrow is commonly not visible. The probability of fish trace makers is supported by experiments.
EN
Graphoglyptids are diagnostic ichnofossils of the Paleodictyon ichnosubfacies (Nereites ichnofacies), which is well represented in deep-marine Mesozoic.Cenozoic thin-bedded turbidites. However, unusual shallow-water records of Mesozoic-Cenozoic Paleodictyon and particular preservational restrictions of graphoglyptid burrows introduce the question of whether graphoglyptids are reliable bathymetric indicators. We document and discuss another unusual graphoglyptid association preserved in shallow-marine, high-energy, organic-rich, and bioturbated turbidites of leveed channels in the upper middle Eocene CCa member, Cerro Colorado Formation, Fuegian Andes. The member includes the facies associations: 1) mudstones, 2) interbedded mudstones and thin-bedded Tbc turbidites, and 3) thick-bedded sandstones andmudstones. Facies association 3), interpreted as channel deposits, records at least three horizons with Desmograpton, Glockerichnus, Helicolithus, Helminthorhaphe, Megagrapton, Paleodictyon and Urohelminthoida. Associated beds are lenticular, channeled sandstone turbidites with marked basal erosion surfaces and variable proportions of interbedded mudstone-sandstone with high content of plant debris. Trace fossils in the channeled sandstones are dominated by Ophiomorpha rudis and O. annulata; mudstones within the thick-bedded mudstone-sandstone beds bear Nereites, Phycosiphon, Zoophycos and Paradictyodora, with subordinate Schaubcylindrichnus, Tasselia and Scolicia. The unusual preservation of limited graphoglyptid-bearing beds within a highly energetic and bioturbated interval seems to support the concept that preservational restrictions on graphoglyptid burrows could be locally more important than bathymetric constraints.
11
Content available remote Da Vinci's Paleodictyon : the fractal beauty of traces
EN
The origins of ichnology are located in a land of convergence between Art and Science, in a historical period - the Renaissance - during which the scientific method had its birth. Trace fossils were studied and graphically represented by preeminent naturalists such as Leonardo da Vinci, Konrad Gesner, Johann Bauhin and UlisseAldrovandi - who defined ichnofossils as "exceptionally beautiful". In this study, the representation of trace fossils in the Renaissance is explored by employing a method widely used in studying visual perception - fractal geometry. In particular, this paper focuses on the reasons for the aesthetic appeal of traces and proves that (1) the aesthetic perception of traces is closely tied to their fractal dimension, and (2) many traces are aesthetically appealing because they have fractal behaviour. In particular, graphoglyptids and chondritids display significant fractal-like features that are linked with their constructional program and function. Such fractal traces are hierarchically structured and their whole geometric structure can be regarded as an expression of self-organization processes producing correlations between different orders of scale.
12
PL
W utworach międzywydmowych piaskowców tumlińskich pstrego piaskowca, w kamieniołomie na Górze Grodowej, znaleziono bogaty zespół tropów kręgowców. Oznaczone dotychczas ichnotaksony: Amphisauropus cf. latus, Rhynchosauroides cf. pallini, Varanopus cf microdactylus, Palmichnus sp., Chelichnus ? sp., "Proterosuchia indet. " były dotychczas znane z utworów permu Europy i Ameryki Północnej. Zespół ten, niewiele starszy od zespołu tropów kręgowców z warstw łabiryntodontowych z Wiór koło Ostrowca Świętokrzyskiego zawierającego typową dla triasu ichnofaunę wskazuje, że wyraźna zmiana zespołu ichnofauny kręgowców w pobliżu granicy permu i triasu nastąpiła w Górach Świętokrzyskich dopiero we wczesnym triasie.
EN
Rich vertebrate track assemblage has been found in the interdune deposits of Tumlin sandstone of the Buntsandstein at the quarry of Grodowa Hill. The ichnotaxa which have been hitherto designated as Amphisauropus cf. latus, Rhynchosauroides cf. pallini Varanopus cf. microdactylus, Palmichnus sp., Chelichnus ? sp., "Proterosuchia indet. " have been hitherto known from the Permian of Europe and North America. This assemblage as only somewhat older than the vertebrate footprint assemblage from Labyrinthodontidae Beds from Wióry near the town of Ostrowiec Świętokrzyski containing typical Triassic ichnogenera representafives shows, that a distinct change of terrestrial vertebrate ichnofauna near the Permian/Triassic boundary occurred in the Holy Cross Mts. area in the Early Triassic time.
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