| 1. |
- Bajdek, Piotr, et al.
(författare)
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Microbiota and food residues including possible evidence of pre-mammalian hair in Upper Permian coprolites from Russia
- 2016
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Ingår i: Lethaia. - : Scandinavian University Press / Universitetsforlaget AS. - 0024-1164 .- 1502-3931. ; 49:4, s. 455-477
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Tidskriftsartikel (refereegranskat)abstract
- Coprolites (fossil faeces) provide direct evidence on the diet of its producer and unique insights on ancient food webs and ecosystems. We describe the contents of seven coprolites, collected from the Late Permian Vyazniki site of the European part of Russia. Two coprolite morphotypes (A, B) contain remains of putative bacteria, cyanobacteria, fungi, protists, invertebrate eggs, arthropod elements, undigested bone and tooth fragments, fish scales and elongated hair-like structures with hollow interiors. Content, size and shape of the coprolites together with the associated body fossil record suggest that the most probable scat-producers were carnivorous tetrapods; the bone-rich morphotype A reveals short food retention time and a fast metabolism and is therefore assigned to therapsid carnivores whereas morphotype B with rarer and degraded bones are assigned to archosauromorphs or other non-therapsid carnivores. The general coprolite matrix contains abundant micron-sized spheres and thin-walled vesicles which are interpreted as oxide and phosphatic pseudomorphs after microbial cells. From analyses of the undigested bones, we infer that they represent remains of actinopterygian fish, a therapsid and unrecognizable parts of amphibians and/or reptiles. Additionally, hair-like structures found in one coprolite specimen occur as diagenetically altered (oxide-replaced) structures and moulds (or partly as pseudomorphs) in a microcrystalline carbonate-fluoride-bearing calcium phosphate. This suggests that the latest Permian therapsids probably were equipped with hair-like integument or hairsuit. If true, this is by far the oldest evidence of this mammalian character in the stem group of mammals.
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| 2. |
- Bajdek, Piotr, et al.
(författare)
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Putative dicynodont coprolites from the Upper Triassic of Poland
- 2014
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 411, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- A significant number (more than 100) of brownto dark and silty, carbonate or pyrite-mineralized, in part organic carbon-rich, spherical or oval-shaped structures have been collected fromthe Upper Triassic (uppermost NorianlowerRhaetian) sediments of the Lipie Śląskie clay-pit at Lisowice near Lubliniec town, Poland. Their geological context, morphology, content, geochemistry and association with skeletal remains suggest they are fecal masses of a sizable herbivorous tetrapod. The only large herbivore known from the site is a giant 5 meter-long dicynodont (Synapsida: Anomodontia), represented by numerous bones and also by large, oval-shaped footprints. The putative dicynodont coprolites were collected from mudstone and siltstone with numerous organic remains that were deposited in anoxic conditions. In addition, REEs and other trace element concentrations suggest that the burial environment and diagenesis of these coprolites were under anoxic conditions. SEM and thin section images of the coprolite matrix show numerous nests with pyrite (probably bacterial in origin) and large amount of mineral particles. The putative dicynodont coprolites contain also amorphous, dark organic matter, poorly preserved palynomorphs, small fragments of plant cuticle. Detailed characteristic of these coprolites reveals possible implications for the ecology and physiology of the source animal species. The δ 13C values of the gymnospermcuticle and dark organic matter measured in three coprolites are −23.4‰, −21.2‰and −20.3‰, all average. The evidence from these coprolites suggests that dicynodonts processed plant soft elements into very small pieces, but wood fragments were found also in a mass accumulation in two coprolites.
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| 3. |
- Bajdek, Piotr, et al.
(författare)
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Residues from the Upper Permian carnivore coprolites from Vyazniki in Russia - key questions in reconstruction of feeding habits
- 2017
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : ELSEVIER SCIENCE BV. - 0031-0182 .- 1872-616X. ; 482, s. 70-82
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Tidskriftsartikel (refereegranskat)abstract
- Residues of twenty-five coprolite fragments collected from the Upper Permian of Vyazniki (European Russia) were studied in detail. The phosphatic composition, general shape and size, and bone inclusions of these specimens indicate that medium to large-sized carnivores, such as therocephalian therapsids or early archosauriforms, were the most likely coprolite producers. The contents of the examined fossils (i.e. Scale, bone and tooth fragments, mineral grains, and microbial structures) do not differ significantly among the samples, implying fairly comparable feeding habits of their producers. Fragments of large tooth crowns in two of the analyzed samples imply that either (1) the coprolite producer swallowed the cranial elements of its prey or (2) the coprolite producer broke and swallowed its own tooth while feeding (such tooth damage is known in archosaurs that have tooth replacement, e.g. crocodiles and dinosaurs). Indeed, the most complete tooth fragment in these fossils is serrated, most likely belonging to an early archosauriform known from skeletal records from the Late Permian of Vyaznilci. Another coprolite fragment contains the etched tooth of a lungfish, while putative actinopterygian fish remains (scales and small fragments of bones) are abundant in some samples. Mineral particles (mostly quartz grains, feldspars and mica) may have been swallowed accidentally. The preserved microbial colonies (mineralized fossil fungi and bacteria or their pseudomorphs), manifested in the coprolites as Fe-rich mineral structures, seem to have developed on the expelled feces rather than on the items before they were swallowed.
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| 4. |
- Niedzwiedzki, Grzegorz, et al.
(författare)
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An Early Triassic polar predator ecosystem revealed by vertebrate coprolites from the Bulgo Sandstone (Sydney Basin) of southeastern Australia
- 2016
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 464, s. 5-15
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Tidskriftsartikel (refereegranskat)abstract
- Vertebrate trace fossils often provide a measure of cryptic biodiversity, and are especially pertinent when skeletal remnants are exceptionally rare. The Lower Triassic (lower Olenekian) Bulgo Sandstone at Long Reef in the Sydney Basin of southeastern Australia constitutes just such a deposit, having yielded isolated bones of giant capitosaurian temnospondyls and proterosuchid archosauriforms, together with abundant coprolites that are geochemically rich in elemental phosphate and carbon denoting vertebrate predators. Microstructural analysis of these preserved droppings reveals occasional bone fragments, fish scales, insect cuticles, plant material and bacterial traces (pseudomorph voids), as well as silicate mineral particles. REE concentrations indicate that burial and early diagenesis occurred explicitly within fluvial sediments. Furthermore, external morphological characterization permits attribution of spiral coprolites to chondrichthyan or osteichthyan fishes, polygonal, ovoid spherical and typically flattened feces to temnospondyls, and conspicuously large cylindrical droppings to archosauriforms or other amniote apex predators. Collectively, the Bulgo Sandstone coprolite assemblage thus offers new insights into ecosystem structure and palaeoenvironment in what was an earliest Triassic near polar setting. Such data compliments the documented skeletal record, but indicates a greater range of aquatic and possibly terrestrial carnivores the latter being enigmatically sparse in the Australian Triassic and yet detected here via the hitherto underexplored trace fossil evidence of their ecological presence.
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| 5. |
- Niedzwiedzki, Grzegorz, et al.
(författare)
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Reduction of vertebrate coprolite diversity associated with the end-Permian extinction event in Vyazniki region, European Russia
- 2016
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 450, s. 77-90
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the paleoecological significance of vertebrate coprolites collected from seven sections and three lithofacies of the uppermost Permian and lowermost Triassic succession from the Vyazniki site in the European part of Russia. The analyzed specimens (coprolites and possibly some cololites) were grouped into nine morphotypes (A-I). The coprolite morphotypes were characterized geochemically and compared to the record of other Permian and Triassic coprolites worldwide. Based on the stratigraphic position, shape, structure and composition, all morphotypes were linked to supposed producers. The phosphatic composition of most of the morphotypes and inclusions of arthropod remains, fish scales and bone fragments, suggest that they were produced by carnivores, but non-phosphatic, carbonate-rich, large and oval-shaped coprolites with impressions after plant remains have also been found. The extinction of terrestrial vertebrates around the Permian-Triassic boundary in Russia is interpreted to have occurred within a few thousands of years. Here, we show a pattern of coprolite morphotypes disappearing across this boundary that is consistent with a relatively sudden change in the vertebrate faunal composition across this interval.
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| 6. |
- Talanda, Mateusz, et al.
(författare)
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Upper Triassic freshwater oncoids from Silesia (southern Poland) and their microfossil biota
- 2017
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Ingår i: Neues Jahrbuch für Geologie und Palaontologie - Abhandlungen. - : E SCHWEIZERBARTSCHE VERLAGSBUCHHANDLUNG. - 0077-7749. ; 284:1, s. 43-56
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Tidskriftsartikel (refereegranskat)abstract
- Oncoids are rare components of Keuper sediments across Europe. The exceptions are localities linked to the Upper Triassic "Wozniki Limestone" (formally Limestone Member from Wozniki) in Silesia, southern Poland. Numerous oncoids occur in breccia-like deposits in the Lipie Slaskie clay pit at Lisowice. The oncoid-bearing level is underlying by organic-rich carbonaceous mudstone and siltstone and covered by non-carbonaceous sandstone and grey wacke sandstone-mudstone heterolithic deposits. The oncoids are of various shapes and are built by agglutinated or skeletal stromatolites composed of a rhythmically grown dendroid micropeloidal framework. The agglutinated stromatolites are poor in microfabrics. The oncoids consist of a smooth or granular outer part and distinct core (carbonate, carbon-rich or phosphate), which may be a fossil (bivalve shell, wood fragment, charcoal piece, carbon-rich coprolite or hone fragment). Dark laminae of the cortex are carbonate-rich, whereas the light ones are silica-rich. They exhibit remains of bacterial/cyanobacterial filaments, as well as some rare and not well-discernible palynomorphs. Ostracods (cf. Darwinula sp.), small fragments of vertebrate bones (mainly fish remains), fragments of wood, plant cuticles and fragments of unionoid bivalves are associated with the oncoid accumulations. Thus, they may have been formed in a shallow freshwater environment and were buried by rapid flood events or mud runoff.
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