Wyniki wyszukiwania - BazTech

1

Stem chondrichthyan microfossils from the Lower Old Red Sandstone of the Welsh Borderland

Burrow C. J., Turner S.

Acta Geologica Polonica

|

2018

|

Vol. 68, no. 3

321--334

EN

Placoid and polyodontode scales of stem chondrichthyans have been found in the early Lochkovian “Ditton Group” of the Brown Clee Hill district, Shropshire, England and at Talgarth, south Wales. One of the forms is assigned to a new species of Altholepis Karatajūtė-Talimaa, 1997, a genus already recognised from Lochkovian shallow marine deposits in Celtiberia, Spain and the Northwest Territories, Canada as well as the type locality in Podolia, Ukraine. Altholepis salopensis sp. nov. is based on small polyodontode scales with typically three to eight high odontodes; the scale form was previously considered to belong to acanthodian “Nostolepis” robusta (Brotzen, 1934). The structure of other scales formerly assigned to “Nostolepis” robusta has led us to erect a new genus Jolepis for this scale form, which differs from Altholepis in lacking an ordered layout of odontodes. Jolepis robusta (Brotzen, 1934), originally (and possibly still) considered to be an acanthodian, is also known from the Baltic countries, Russia, and northern Germany (ex erratic limestones). Scales of acanthodian Parexus recurvus Agassiz, 1845, and/or possibly from the stem chondrichthyan Seretolepis elegans Karatajūtė-Talimaa, 1968 (scales of these two taxa are barely distinguishable), and of stem chondrichthyan Polymerolepis whitei Karatajūtė-Talimaa, 1968 are also present. Altholepis, Jolepis gen. nov., Seretolepis Karatajūtė-Talimaa, 1968 and Polymerolepis KaratajūtėTalimaa, 1968 are found in marine deposits elsewhere; the British occurrence of these taxa adds to the debate on the sedimentological origins of the Lower Old Red Sandstone deposits in the Welsh Borderland. The geographic range of several early sharks is now known to extend around the Old Red Sandstone continent and beyond.

2

Acanthodians from the Lower Devonian (Emsian) ‘Placoderm Sandstone’, Holy Cross Mountains, Poland

Burrow C. J., Szrek P.

Acta Geologica Polonica

|

2018

|

Vol. 68, no. 3

307--320

EN

The Lower Devonian ‘Placoderm Sandstone’ in the Holy Cross Mountains (HCM) is filled with abundant impressions of disarticulated vertebrate remains. The only acanthodian macroremains named to date are fin spines of Machaeracanthus polonicus Gürich. Fin spine impressions in slabs from the Winna Formation (Emsian) at Podłazie Hill (near Daleszyce) in the southern HCM, and also the Barcza Formation (?Lochkovian) at Barcza Quarry, Miedziana Góra Conglomerate (?Lochkovian), Gruchawka, and Zagórze Formation (middle–upper Emsian) at Bukowa Mountain in the northern HCM, reposited in the University of Warsaw, Polish Geological Institute-National Research Institute, Warsaw, and Natural History Museum, London collections, have been cast and studied in order to better document this poorly known taxon. As noted in other Machaeracanthus species, we have found that M. polonicus has two different morphotypes of spines, which abut lengthwise to form a pair of spines. Our investigations show that the fin spine assemblage includes Onchus overathensis as well as M. polonicus, and probably another undetermined acanthodian. The affinities of O. overathensis are reassessed. It is here considered to be a diplacanthiform, and reassigned to the genus Striacanthus, as S. overathensis. Acanthodian scapulocoracoids have also been identified, as well as tightly spiralled toothwhorls which could be from an acanthodian.

3

Nowe dane na temat fauny kręgowców w "piaskowcach plakodermowych" z rejonu Daleszyc (Góry Świętokrzyskie)

Szrek P.

Przegląd Geologiczny

|

2003

|

Vol. 51, nr 5

409-411

PL

Na podstawie wstępnej analizy oznaczeń fauny z "piaskowców plakodermowych" Güricha (1896) oraz Czarnockiego (1919) i porównaniem ich z nową kolekcją (nr OS-223) stwierdzono, że oznaczenie tejże fauny na poziomie rodzajów i gatunków, jest bardzo niepewne i może budzić kontrowersje. Nie mogąc jednak przebadać kolekcji Güricha i Czarnockiego (zaginęły w czasie wojny), autor po analizie swojego materiału potwierdził obecność prawie wszystkich wymienionych przez Güricha (1896) i Czarnockiego (1919) rzędów i rodzin ryb pancernych. Stwierdzono występowanie licznych przedstawicieli Arthrodira, a także odcisków płyt przedstawicieli rzędu Antiarcha, którego obecność w dewonie świętokrzyskim w ogóle, była wątpliwa.

EN

Preliminary analysis of descriptions of "Placoderm Sandstone "fauna by Giirich (1896) and Czarnocki (1919), and comparison with the author 's new collection (no. OS-223), revealed that identification of that fauna at the species level is dubious. It is unlikely to see the Giirich and Czarnocki 's collections (lost during the war time). Review of the newly collected material confirmed the presence of almost all the orders and families of placoderm fish listed by Giirich and Czarnocki. Especially important is the rediscovery of fragments ofantiarchs, as the whose presence of the order Antiarcha in the Devonian of the Holy Cross Mountains was doubted. Besides, the presence of the Arthrodira representatives is documented.