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Badenian (middle Miocene) decapod crustaceans from western Ukraine, with remarks on eco-taphonomy, palaeoecology and biogeography

Górka M.

Acta Geologica Polonica

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2018

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Vol. 68, no. 4

511–-535

EN

The decapod fauna from the Badenian (middle Miocene) deposits of western Ukraine comprises in total 31 taxa: 20 species, 9 taxa left in open nomenclature, and 2 determined at family level. Thirteen of these taxa are reported for the first time from the territory of Ukraine. Among them are the first records of Trapezia glaessneri Müller, 1976 in the Fore-Carpathian Basin and Pachycheles sp. in Paratethys. One taxon (Petrolisthes sp. A) probably represents a new species. The occurrence of this significant decapod fauna is restricted almost exclusively to the Upper Badenian (i.e., early Serravallian) coralgal reefs of the Ternopil Beds. The taxonomic composition of the decapods indicates that the Late Badenian depositional environment was a shallow marine basin dominated by reefs that developed in warm-to-tropical waters of oceanic salinity. The decapod assemblage from the Ternopil Beds is similar in its taxonomic composition to numerous decapod faunules from fossil reefs of Eocene to Miocene age from the Mediterranean realm and of Miocene age from Paratethys. In contrast, decapod remains are very scarce in Badenian siliciclastic deposits (Mikolaiv Beds) and are represented by the most resistant skeletal elements, i.e., dactyli and fixed fingers. This scarcity was caused by the high-energy environment, with frequent episodes of redeposition, which disintegrated and abraded the decapod remains. The decapod fauna from the Badenian (middle Miocene) deposits of western Ukraine comprises in total 31 taxa: 20 species, 9 taxa left in open nomenclature, and 2 determined at family level. Thirteen of these taxa are reported for the first time from the territory of Ukraine. Among them are the first records of Trapezia glaessneri Müller, 1976 in the Fore-Carpathian Basin and Pachycheles sp. in Paratethys. One taxon (Petrolisthes sp. A) probably represents a new species. The occurrence of this significant decapod fauna is restricted almost exclusively to the Upper Badenian (i.e., early Serravallian) coralgal reefs of the Ternopil Beds. The taxonomic composition of the decapods indicates that the Late Badenian depositional environment was a shallow marine basin dominated by reefs that developed in warm-to-tropical waters of oceanic salinity. The decapod assemblage from the Ternopil Beds is similar in its taxonomic composition to numerous decapod faunules from fossil reefs of Eocene to Miocene age from the Mediterranean realm and of Miocene age from Paratethys. In contrast, decapod remains are very scarce in Badenian siliciclastic deposits (Mikolaiv Beds) and are represented by the most resistant skeletal elements, i.e., dactyli and fixed fingers. This scarcity was caused by the high-energy environment, with frequent episodes of redeposition, which disintegrated and abraded the decapod remains.

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Queues of blind phacopid trilobites Trimerocephalus: A case of frozen behaviour of Early Famennian age from the Holy Cross Mountains, Central Poland

Radwański A., Kin A., Radwańska U.

Acta Geologica Polonica

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2009

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Vol. 59, no. 4

459-481

EN

An assemblage of blind phacopid trilobites of the genus Trimerocephalus McCoy, 1849, representing either the species Trimerocephalus mastophthalmus (Reinhard Richter, 1856) or its allies (possibly, a new species), from an Early Famennian (Early Marginifera Zone) marly sequence of the Holy Cross Mountains, Central Poland, is composed of well organized single-file queues. The trilobites in the queues appear almost intact, having been preserved in the position they kept when forming the queues, and are interpreted showing migratory behaviour known in various present-day arthropods, but unreported from the fossil state. This queuing was induced by environmental stress caused by a dramatic drop in sea level, temporarily leading to emersion. The preservation of the queues at omission horizons is thus ascribed to a mass mortality event, caused by subaerial exposure. The trilobites were suffocated and fossilized in a mortal spasm, and finally blanketed by calcareous ooze when inundated at a highstand. The assemblage of trilobite queues represents a unique example of frozen behaviour and a snapshot of the geological past.

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Kolonie korali z muszlowców ostrygowych i oolitów dolnego kimerydu Małogoszcza

Radwański A., Roniewicz E.

Volumina Jurassica

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2005

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Vol. 3, no. 1

97--107

EN

Scleractinian corals occurring scarcely in the Lower Kimmeridgian Actinostl'eon (=Lopha, =Alectryonia) shellbeds at Malogoszcz in the Holy Cross Mountains, Central Poland, are represented by abraded colonies densely riddled by rock-boring bivalves (Lithophaga inclusa Phillips, GastTOchaena sp.) and polychaetes (potamilla sp.). The taxonomically recognised specimens include C01nplexastrea bUJ'gundiae (de Blainville, 1830), D 'imorphocoenia sp., Ovalastrea caryophylloides (Goldfuss, 1826), and Thamnasteria graeilis (Miinster, 1826). AlI colonies are preserved in the form of hollows, the wall s of which bear moulds of coral calyces, and of bivalve and polychaete borings. Taking into account the structural features of shellbeds and their faunistic content (uprooted crinoids Apioerinites, dug-out deeply-infaunal bivalves), stormy agitation is postulated as a basic agent responsible for damaging AeUnostreon communities, and their associates. The studied corals are thought to have lived aside the Aetinostreon gardens, up on a muddy bottom, from where they have been stirred-up during the storm cataclysm, having been then abraded and riddled by rock-borers repeatedly until laid down in a shellbed and transferred in to the fossil record. The extremely shallow-water conditions, under which the ostreid Actinostreon has lived, suggest the typically opportunistic nature or the associated corals, the same as of Ovalastrea caryophylloides (Goldfuss, 1826) from oolitic shoals, and the only colony of which completes the coral assemblage of Malogoszcz. The opportunism or ali these corals differs them from the habit of hermatypie forms from coeval and Oxfordian patch-reef communities of the Holy Cross Mountains (ef. Roniewicz & Roniewicz 1968, 1971).

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Gąbki wapienne Elasmostoma lomes W. Mliller, 1984, z dolnego kimerydu Karsów koło Korytnicy, ich ekofenotypia i tafonomia

Radwański A.

Volumina Jurassica

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2005

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Vol. 3, no. 1

109--121

EN

Calcareous sponges Elastostoma !'omes W MUller, 1984, from the Lower Kimmeridgian marly onkolitic limestones exposed at Karsy in the Holy Cross Mountains, Central Poland, are studied in terms of their settlement, growth, behaviour, and resulting phenotypy. The lichen-shaped auriculate specimens are interpreted as growing upwardly, at a higher angle to the bottom surface, in order to involve passive flow carrying suspended nutrients up on which they fed. Unstable bottom and hydrodynamie conditions, under which the growth of sponges progressed, we re basic prerequisites that controlled ecophenotypic variability of the studied specimens, A peculiar case of regeneration is discussed, to postulaie the skeleton parts having been lithified during the sponge's life, and healed after an accidental injury. Aviolent event that caused catastrophic burial of the studied sponge assemblage is ascribed to high-energy agents, most likely of storm origin.

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Eko-tafonomia serpulitów tytonu Brzostówki i Sławna na tle badań wieloszczetów dzisiejszych

Radwańska U.

Volumina Jurassica

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2003

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Vol. 1, no. 1

99-104