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Trace fossils from the Mississippian of the Piaskowa Góra section (the Intra-Sudetic Basin, SW Poland)

Muszer Jolanta

Annales Societatis Geologorum Poloniae

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2020

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Vol. 90, No. 2

195--213

EN

Eight ichnotaxa and enigmatic tubular forms were discovered and described for the first time from clastic deposits (the Culm facies) of the uppermost part of the Szczawno Formation (upper Mississippian) from in the Piaskowa Góra section in the northern part of the Intra-Sudetic Basin near Wałbrzych. The trace fossils are represented mostly by pascichnia and less numerous domichnia, fodinichnia and repichnia. Psammichnites plummeri and numerous Phycosiphon isp. are the most common ichnotaxa. They are accompanied by Archaeonassa fossulata, Beaconites cf. capronus, Curvolithus multiplex, Dictyodora liebeana, Palaeophycus isp., and Planolites isp. D. liebeana is described for the first time from the lower Serpukhovian. Most components of the ichnoassem-blage are typical of the Cruziana ichnofacies, but the co-occurrence of Dictyodora and Phycosiphon could indicate a transition to deeper environmental settings (the Zoophycos ichnofacies). The lithological features as well as the accompanying trace fossils, wrinkle structures and floral remains of Archaeocalamites indicate rapid sedimentation, alternating with more tranquil periods of sedimentation, in an intermediate environment between the lower offshore (the distal Cruziana ichnofacies) and the fan-delta slope (below the wave base, the Zoophycos ichnofacies). The studied trace fossils and palynological data indicate that marine conditions in the Wałbrzych area in the Mississippian prevailed locally until the early Sepukhovian.

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First report on swimming trace fossils of fish from the Upper Permian and Lower Triassic of the Dolomites (Italy)

Ronchi A., Santi G., Marchetti L., Bernardi M., Gianolla P.

Annales Societatis Geologorum Poloniae

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2018

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Vol. 88, No. 2

111--125

EN

In the Upper Permian continental to marginal-marine succession of the Southern Alps (Dolomites, north Italy), the ichnological record consists of diverse vertebrate footprints and non-diverse invertebrate trace fossils, mainly occurring in the “Bletterbach ichnoassociation” of the Val Gardena Sandstone Formation. After the Permian-Triassic Boundary event, vertebrate ichnoassociations are scarce until the Middle Triassic (Anisian), whereas the uppermost Permian-Lower Triassic Werfen Formation preserves a rich invertebrate trace-fossil record. To date, fish body and trace fossils (Undichna) are very rare in the pre- and post-extinction deposits of the Dolomites; only Undichna gosiutensis Gibert, 2001 was identified in the “Voltago Conglomerate” (Middle Anisian), whereas some unidentified fossil fish casts were found in the Permian Val Gardena Sandstone and some fish remains in the overlying Werfen Formation. Recently, for the first time, fish trails have been discovered in the Val Gardena Sandstone (Lopingian) and in the Werfen Formation (Campil member, Early Triassic, Smithian). Val Gardena Sandstone yielded Undichna cf. quina Trewin, 2000 and U. bina Anderson, 1976 and these represent the oldest fish trails found in the Southern Alps so far. Conversely, the specimens found in the Werfen Formation can be assigned to Undichna cf. britannica Higgs, 1988. They represent the oldest Mesozoic record of fish trace fossils in northern Italy and one of the few records of Undichna from marine environments. These trace fossils are consistent with the fossil association found in the two formations and reflect fish swimming activity in different environments: in very shallow, calm, brackish distal-floodplain to marginal-marine environments in the Late Permian, in association with abundant and diverse tetrapod tracks, and non-diverse invertebrate trace fossils, and in inter- to subtidal calm, shallow, marine environments in the Early Triassic, together with abundant, but not diverse invertebrate trace fossils.

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Unusual preservation of Ophiomorpha in middle Miocene rocks of Wadi Zablah, east Matruh area, northwestern Egypt

Gameil M., Sadek S.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

39-44

EN

Unusual biogenic structures in the form of hollow burrows are preserved in middle Miocene sandy limestones (calcarenites) exposed in Wadi Zablah, east of the town of Mersa Matruh along the Egyptian Mediterranean coast. This calcarenite unit is about 30 m thick and lies in the middle part of the Marmarica Formation. The burrows commonly are up to 2.5 m long and can reach a length of 3 m in some outcrops. The internal diameter ranges from 1 to 5 cm. In most cases there is a hard cemented zone surrounding the hollow burrows that ranges in thickness from 0.2 to 0.4 cm. In several burrows where the hard cemented zone is preserved, a knobby sculpture is visible on the internal surfaces of the burrows. This is considered to be a negative mold of the pelleted wall of Ophiomorpha. This inverted knobby sculpture is formed by the cemented zone, which permitted the trace fossils. preservation, the original Ophiomorpha wall having been dissolved away during or subsequent to lithification by subsequent weathering processes. The presence of these burrows in association with marine fossils suggests a littoral to very shallow shelf environment.

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The trace fossil Rusophycus versans from the Furongian (Upper Cambrian) of central Poland - an example of behavioural convergence amongst arthropods

Sadlok G., Machalski M.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

119-123

EN

Traces assigned to Rusophycus versans are recorded for the first time from Furongian (Upper Cambrian) strata, as exposed at Wiśniówka Wielka quarry, Holy Cross Mountains, central Poland. These traces are ascribed to the life activity of trilobites in a fully marine environment. In contrast, previous records of R. versans have been attributed to notostracans, isopods or arthropleurids and are preserved in non-marine settings. The relatively wide phylogenetic distribution of R. versans within various arthropod groups indicates that this ichnotaxon represents behavioural convergence amongst arthropods.

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Ichnocoenoses in the Oligocene to Miocene foredeep basins (Northern Apennines, central Italy) and their relation to turbidite deposition

Monaco P., Checconi A., Milighetti M.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

53-70

EN

Analysis of trace fossil abundance and diversity in the Oligocene to Miocene foredeep and piggyback basins of the Tuscan-Romagna-Umbrian Apennines allows us to recognize five ichnocoenoses. The deposits reflect sedimentary environments from slope to basin plain, whose sedimentation was directly controlled by synsedimentary tectonics: attached fan lobes and channels, lobe- and channel-fringes, overbank-fringes of intrabasinal highs, distal detached lobes of basin plain and slope-proximal interfans. The graphoglyptid: non-graphoglyptid ratio has been considered as the chief factor in the study of ichnologic material from Falterona-Cervarola-Trasimeno, Marnosoarenacea and Marne di Vicchio-Verghereto stratigraphic units. The study shows that there is an increase in ichnodiversity and ichnodensity of graphoglyptids, which are typical mainly in detached lobes of basin plain and overbank-levee deposits whose background ichnofauna also shows better preservation.

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Deep-sea ichnology : observations in modern sediments to interpret fossil counterparts

Wetzel A.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

125-138

EN

Extensive areas of the abyss represent a dynamic environment experiencing seasonally strongly fluctuating organic-matter deposition that in turn affects the oxygen content of the pore water. At high organic-matter deposition, oxygenation of the pore water decreases and forces organisms respiring this water to move upward. Thus, times of benthic food richness on the seafloor affect the behaviour of endobenthic organisms; aside from deep-deposit feeding, temporary surface feeding (including unselective bulldozing) represents an additional nutritional strategy. This has been shown for the producers of Nereites and Scolicia as well as Thalassinoides and Zoophycos, the latter two have an open tube. Each of these activities leads to intense sediment mixing and prevents or disturbs the formation of near-surface burrows including graphoglyptids. The distribution of organic matter in the sediments is reflected by the orientation and geometry of Phycosiphon. Quantity and quality of food appear to be related to abundance and size of Scolicia. Food selectivity, the ability of selective feeding and organism mobility all appear to be important factors in benthic ecology, however, they are as yet little known. To use the full potential of uniformitarian studies relying on cores taken in soft sediments, they should be based on X-ray radiographs, contain information about the timing of burrow production and focus on ichnotaxonomically determinable burrows.

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Trace fossils from the Lower-Middle Jurassic Bardas Blancas Formation, Neuquen Basin, Mendoza Province, Argentina

Bressan G., Palma R.

Acta Geologica Polonica

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2009

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Vol. 59, no. 2

201-220

EN

Trace fossil associations from the Lower.Middle Jurassic siliciclastic succession of the northern Neuquen Basin, Argentina are described and their palaeoenvironmental interpretation is discussed. The Bardas Blancas Formation displays facies of lower foreshore to offshore environments, such as massive and laminated mudstones, laminated siltstones, hummocky cross-stratified sandstones, massive and laminated sandstones, wave-rippled sandstones, as well as fine- to medium-grained bioclastic sandstones and massive conglomerates. They contain a trace fossil assemblage low in abundance but high in diversity. The assemblage, comprising eleven ichnogenera, is dominated by Skolithos, Chondrites, Thalassinoides, Planolites, Palaeophycus, Taenidium, Gyrochorte and Arenicolites. Gordia, ?Diplocraterion and Lockeia are less abundant. These trace fossils belong to the Skolithos, Cruziana and Zoophycos ichnofacies. Their distribution is controlled mainly by hydrodynamic energy, substrate consistency and oxygen levels. Storm beds exhibit two successive stages of colonization: (1) the pioneer stage, during which Skolithos, Diplocraterion and Arenicolites (elements of the Skolithos ichnofacies), were produced; and (2) the stable environment stage, represented by Chondrites, Thalassinoides, Taenidium, Gyrochorte, Gordia, Lockeia, Palaeophycus and Planolites (elements of the Cruziana ichnofacies). deeper environments exhibit a low diversity association with Chondrites and Thalassinoides, characterizing the Zoophycos ichnofacies.

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Palaeoecologic significance of Late Jurassic Trace fossils from the Boulonnais, N France

Schlirf M.

Acta Geologica Polonica

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2003

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Vol. 53, nr 2

123-142

EN

Late Jurassic invertebrate trace fossil assemblages studied at outcrops along the coastline of the Boulonnais (northern France) are described and their paleoenvironmental interpretations are discussed. The ichnofauna shows a high diversity (36 ichnospecies). Predominant forms are Spongeliomorpha suevica, S. nodosa, Treptichnus, Asterosoma, Rhizocorallium irregulare, Rh. jenense, Diplocraterion, Teichichnus, Rosselia, Skolithos, Cochlichnus, Gyrochorte, and Bolonia lata. Following SEILACHER'S (1967) archetypic classification the trace fossils belong to the Skolithos and Cruziana ichnofacies. In a 120 m succession of storm-dominated, nearshore, marine clastics of Kimmeridgian-Tithonian age nine frequent palaeoichnocoenoses and one exceptional palaeoichnocoenosis are identified. Their distributions is mainly controlled by hydrodynamic energy. These energy Levels represented by the host rocks may differ from what the trace fossils indicate. It can be shown that a large proportion of deposit-feeding structures, such as Teichichnus, Rhizocorallium irregulare, and Asterosoma, indicating quiet and stable conditions, although occurring in host sediments indicating high energy conditions. This contradictory observation is attributed to non contemporaneous formation of the sediments and the trace fossils. In a sequence stratigraphic interpretation of the Gres de la Creche at Le Portel, parasequence boundaries are detected with the help of completely bioturbated horizons. The study of trace fossil assemblages thus gives a more detailed and accurate picture of former environmental conditions than sedimentologic methods alone.

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New trace fossils produced by etching molluscs from the Upper Neogene of the southwestern Iberian Peninsula

Santos A., Mayoral E., Muniz F.

Acta Geologica Polonica

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2003

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Vol. 53, nr 3

181-188

EN

New trace fossils produced by etching molluscs gastropods (Crepidula) and bivalves (Ostreacea), from the southwestern part of the Iberian Peninsula (southeast of Portugal and southwestern of Spain) are described. These trace fossils are here described as Lacrimichnus ichnogen. nov. due tothe tear-shape of the scars. Two new ichnospecies are established: L. cacelensis ichnosp. nov. and L. bonarensis ichnosp. nov. Both ichnospecies are of Late Miocene (Late Tortonian) - Holocene age.