20.500.12556/DiRROS-19207 Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine Paleoekološki pomen fosilne sledi Circulichnis Vyalov, 1971 iz karbona Doneškega bazena v Ukrajini The ichnogenus Circulichnis Vyalov is a horizontal a ring- or ellipse-shaped burrow and/or locomotion trace of an unknown producer, most likely an annelid or a “worm”, preserved on the bedding plane. This ichnogenus is known over a wide age interval (Ediacaran–Oligocene). Circulichnis demonstrates a wide ecological range and has been found in continental (Mermia ichnofacies), shelf, and relatively deep-water (turbidites) deposits. It is commonly interpreted as a sediment feeding trace, but the peculiarities of its formation remain somewhat mysterious, as it is unclear how the tracemaker reached the sediment surface, as lateral branches of the ring-shaped traces are extremely rare and have only been observed by a few researchers. A rather large specimen of Circulichnis montanus Vyalov, 1971 with a preserved lateral branch was found in the Mospyne Formation (upper Bashkirian, Lower Pennsylvanian) of the Donets Basin. This discovery confirmed the assumption made by Alfred Uchman and Bruno Ratazzi regarding the peculiarities of formation of Circulichnis. According to these authors, a single ring-shaped Circulichnis indicates an attempt to forage at a specific level in the sediment, while the lateral branches of Circulichnis are part of a vertical shaft leading to another level within the sediment. The study of Circulichnis montanus from the Donets Basin has confirmed that at least variant C of the Circulichnis formation scheme proposed by Uchman and Ratazzi is correct, i.e. the lateral branch is a horizontal or subhorizontal part of a generally vertical shaft. However, it is important to note that the correctness of variants A and B of the Uchman and Ratazzi scheme cannot be excluded. To answer this question unequivocally, new finds of well-preserved Circulichnis are necessary. Ihnofosilni rod Circulichnis Vyalov, 1971 je vodoravna, obročasto ali elipsasto oblikovana sled vrtanja in/ali premikanja neznanih organizmov, najverjetneje anelidov ali “črvov”, ki so se ohranili na površini plasti. Ta ihnofosilni rod je poznan v širokem starostnem intervalu (ediakarij–oligocen). Circulichnis izkazuje širok ekološki razpon in je bil najden v kontinentalnih (Mermia ihnofacies), šelfnih in razmeroma globokomorskih (turbiditnih) sedimentih. Običajno ga tolmačijo kot sled prehranjevanja s sedimentom, vendar posebnosti njegovega nastanka ostajajo nekoliko skrivnostne, saj ni jasno, kako je organizem, ki je pustil sled, dosegel površino sedimenta, saj so stranske veje obročastih sledi izjemno redke in jih je opazilo le nekaj raziskovalcev. V formaciji Mospyne (zgornji baškirij, spodnji pennsilvanij) v Doneškem bazenu je bil najden precej velik primerek vrste Circulichnis montanus Vyalov, 1971. Na tem primerku je ohranjena stranska veja, kar je, kot je navedeno zgoraj, precej redko. To odkritje je potrdilo domnevo Alfreda Uchmana in Bruna Ratazzija o posebnostih nastanka rodu Circulichnis. Po tej domnevi je posamezen obroč Circulichnis poskus prehranjevanja na določeni ravni v sedimentu, medtem ko so stranske veje Circulichnis del vertikalnega rova, ki vodi na drugo raven v sedimentu. Raziskava Circulichnis montanus iz Doneškega bazena je pokazala, da je pravilna vsaj varianta C sheme nastanka rodu Circulichnis, ki sta jo predlagala Uchman in Ratazzi, tj. stranska veja je horizontalni ali subhorizontalni del sicer vertikalnega rova. Vendar to ne izključuje pravilnosti variant A in B Uchmanove in Ratazzijeve sheme. Nedvoumen odgovor na to vprašanje bodo lahko dale le nove najdbe dobro ohranjenih primerkov rodu Circulichnis. trace fossils Circulichnis Pennsylvanian Ukraine fosilne sledi Circulichnis pennsylvanij Ukrajina true false true Geološki zavod Slovenije Angleški jezik Slovenski jezik Neznano 2024-07-09 08:32:14 2024-07-09 08:32:14 2024-07-10 03:52:50 0000-00-00 00:00:00 2024 0 0 str. 63-70 no. 1 vol. 67 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2024-06-11 56 0016-7789 10.5474/geologija.2024.004 200529155 1884-Article_Text-12342539-1-10-20240611.pdf 1884-Article_Text-12342539-1-10-20240611.pdf 1 51BDABB4A94C7A935EEA1B3A074D8430 9c17cbf1863d8e873e750a280552359dc64a44d23604a83cb596edb993f8216a 4dbfd66a-3dbd-11ef-b487-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=26443 Geološki zavod Slovenije Geologija 0 0 0