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Wyszukujesz frazę "Lower Devonian" wg kryterium: Temat


Wyświetlanie 1-15 z 15
Tytuł:
Environmental differentiation reflected in the vertebrate fauna diversity in the Lower Devonian of the Holy Cross Mountains, Poland
Autorzy:
Wilk, Olga
Szrek, Piotr
Ginter, Michał
Powiązania:
https://bibliotekanauki.pl/articles/2201204.pdf
Data publikacji:
2022
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
vertebrates
Lower Devonian
Emsian
Holy Cross Mountains
environment
Opis:
The Lower Devonian of the Holy Cross Mountains is well-known in the field of vertebrate palaeontology but remains unrecognized as regards palaeoenvironmental reconstructions. We therefore analysed the spatial distribution and relative abundance of fossil vertebrates in this area within one time interval. The fauna from an Early Devonian (Emsian) siliciclastic bone-bearing breccia (the “Placoderm Sandstone”) exposed in four sections of the Łysogóry region and five sections of the Kielce region was analysed with respect to the frequency of the remains and their taxonomic affinity. The relative abundances of agnathans, acanthodians, placoderms, osteichthyans and chondrichthyans suggest more open marine conditions in the Łysogóry region and more terrestrial-influenced in the Kielce region during the Emsian. The results show that the average agnathan and acanthodian content of the Łysogóry region is significantly larger than that in the Kielce region. On the other hand, there are relatively fewer osteichthyans in the Łysogóry region and a significantly higher proportion of bony fishes was recorded in the fauna of the Kielce region. Placoderms are characterized by their generally similar frequency in both regions and from site to site in each of them, though a greater abundance was noted from the Kielce region. Likewise differences in the proportions of particular groups in the Kielce region suggest a large variety of marginal-marine environments under the influence of factors that might have included marine currents and variable conditions around a river mouth.
Źródło:
Geological Quarterly; 2022, 66, 4; art. 66, no. 35
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Storm origin of bone-bearing beds in the Lower Devonian placoderm sandstone from Podłazie Hill (Holy Cross Mountains, central Poland)
Autorzy:
Szrek, P.
Niedźwiedzki, G.
Dec, M.
Powiązania:
https://bibliotekanauki.pl/articles/2060466.pdf
Data publikacji:
2014
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Placoderm Sandstone
Lower Devonian
Emsian
Holy Cross Mountains
Polska
Opis:
The placoderm sandstone (Emsian, Holy Cross Mountains) exposed in the abandoned quarry at Podłazie Hill was revisited and excavated during fieldwork conducted in 2011-2013. Bone-bearing breccias were identified for the first time at this site and subjected to taphonomic analysis. Vertebrate remains are dominated by heterostracans, while true placoderms compose less than 20% of the total vertebrate assemblage. The high degree of fragmentation of the bones and low degree of abrasion indicate that the remains were reworked and transported before final burial. This is consistent with the mixed character of the bone accumulations, which comprise both open-shelf forms (acanthodians, chondrichthyans) as well as those related to marginal-marine environments (placoderms and sarcopterygians). The bone-bearing succession has been subdivided into five depositional facies attributed to a coastal lagoon influenced by stormy, possibly tidal conditions. The occurrence of the invertebrate trace fossil Ilmenichnus sp. accompanied by Lockeia and Monomorphichnus supports this interpretation.
Źródło:
Geological Quarterly; 2014, 58, 4; 795--806
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Facies transition and biostratigraphic correlation of the Upper Silurian and Lower Devonian in West Bulgaria
Autorzy:
Boncheva, I.
Sachanski, V.
Lakova, I.
Yaneva, M.
Powiązania:
https://bibliotekanauki.pl/articles/2059515.pdf
Data publikacji:
2007
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Bulgaria
Upper Silurian-Lower Devonian
conodonts
graptolites
facies transition
Opis:
Upper Silurian and Lower Devonian shelf deposits in West Bulgaria are exposed in three main Alpine tectonic units: the West Balkan Unit, the Lyubash Monocline and the Morava Unit. The West Balkan and Lyubash units consist of siliciclastic deposits: black graptolitic shales, banded pale shales and black siltstones. The Ludlow, Pridoli, Lochkovian, Pragian and Emsian were recognized on the basis of graptolite and tentaculite faunas. In the Morava Unit, the Ludlow black shales are progressively replaced by clayey limestones and nodular and micritic limestones in the Pridoli and Early Devonian. Newly obtained conodonts show the presence of the siluricus, eosteinhornensis, woschmidti, postwoschmidti, delta-pesavis, sulcatus, dehiscens and gronbergi zones. Petrographic study of the Morava Unit shows an increasing carbonate content and shallowing conditions upwards. The biostratigraphical correlation and facies interpretation reveal the coeval existence of two different depositional environments within the same shelf basin as well as a gradual shift in proximal direction.
Źródło:
Geological Quarterly; 2007, 51, 4; 407-418
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new giant discinoid brachiopod from the Lower Devonian of Algeria
Autorzy:
Mergl, M
Massa, D.
Powiązania:
https://bibliotekanauki.pl/articles/22683.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
systematics
new brachiopod
brachiopod
Devonian
Algeria
Lower Devonian
Germany
Discinoidea
Brachiopoda
paleontology
Opis:
A new discinoid brachiopod Gigadiscina gen. nov., with the type species G. lessardi sp. nov., is described from the Lower Devonian (Siegenian) of the Tamesna Basin (South Ahaggar Massif, South Algeria). It is characterised by large size and convexo−planar profile of the shell, with a subcentral pedicle foramen. Micro−ornament is typically discinoid, with small circular pits in radial rows on the post−larval shell surface. Related species of Malvinokaffric Realm origin from South Africa, Falkland Islands, Antarctica, South America, and Libya are reviewed, including the poorly known Discina anomala from the Lower Devonian of Germany. The giant size and convexo−planar shells of these discinoids, remarkably similar to recent limpets, are interpreted as adaptation to a habitat in proximity of sandy and gravel beaches in a high−energy environment. Most likely, the conical dorsal valve suppressed drag in turbulent waters, whereas fixation of shell by large, sucker−like pedicle eliminated peeling from the substrate.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palynology and microfacies of Lower Devonian mixed carbonate-siliciclastic deposits in Podolia, Ukraine
Autorzy:
Filipiak, P.
Zaton, M.
Szaniawski, H.
Wrona, R.
Racki, G.
Powiązania:
https://bibliotekanauki.pl/articles/19979.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
palynology
microfacies
Lower Devonian
Devonian
carbonate-siliciclastic deposit
Podolia
Ukraine
stratigraphy
cuticle
arthropod
Opis:
Investigation of mixed carbonate−siliciclastic Lower Devonian deposits have been carried out in the Ivanye Zolote and Ustechko sections in Podolia, Ukraine. Based on palynomorph evidence, the age of the samples studied is late Lochkovian, not older than the NM Oppel Miospore Zone, specifically the Si Lineage Zone. The presence of acritarchs and chitinozoans points to dominantly marine depositional conditions. However, a regressive environmental change toward more brackish conditions is indicated by a decrease in the taxonomic diversity of acritarchs in the topmost samples, the simultaneous disappearance of chitinozoans, and an increase in leiosphaerid frequency. Furthermore, evolution of limestone microfacies demonstrates a progressive transition from a shrinking marine basin toward a brackish, storm−affected muddy lagoon, manifested by recurrent profusion of impoverished, mostly opportunistic and euryhaline shelly benthos (nuculanid bivalves, leperditicopids and other ostracods, terebratulid brachiopods), chaetetid demosponges and diverse ichthyofauna. The association of plant (mainly nematophytes and some tracheids) and animal (eurypterid, ?scorpion, and possibly other arthropod) remains points to the presence of nearby Early Devonian wetland vegetation, providing food and shelter for various semi−aquatic and other terrestrial arthropods.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acanthodian jaw bones from Lower Devonian marine deposits of Podolia, Ukraine
Autorzy:
Voichyshyn, V.
Szaniawski, H.
Powiązania:
https://bibliotekanauki.pl/articles/22218.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
acanthodian jaw
jaw bone
Lower Devonian
Devonian
marine deposit
Podolia
Ukraine
Acanthodii
Ischnacanthiformes
Opis:
Ischnacanthiform acanthodian dentigerous jaw bones from the Lower Devonian (Late Lochkovian) of Podolia are described for the first time. One new genus and one new species are established. Podoliacanthus gen. nov. is diagnosed as having small−sized jaw bones, the presence of specific accessory cusps/denticles on the medial side of teeth of the lateral tooth row, and groups of denticles forming the lingual tooth row. Podoliacanthus zychisp. nov. is distinguished in having elongated slender jaw bones and lateral teeth with one medial side denticle. Besides, three species are described in open nomenclature: Podoliacanthus sp. 1, while similar to Podoliacanthus zychi sp. nov., differs in having stronger posterior inclination of the teeth tips and presence of well developed flanges of the teeth, P. sp. 2 has quite robust jaw bones and teeth with two medial side denticles, and Podoliacanthus sp. 3 has small narrow jaw bones and teeth with three medial side denticles. Morphology of the lingual tooth row is considered to be a diagnostic feature of generic and higher taxonomic levels, while accessory medial cusps/denticles of the teeth are regarded as diagnostic features at species level. The new genus also occurs in Upper Silurian or Lower Devonian deposits of North Greenland. Preservation of the jaw bones possibly depends on their secondary mineralization.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spore stratigraphy of Lower Devonian and Eifelian (?), alluvial and marginal marine deposits of the Radom-Lublin area (central Poland)
Stratygrafia sporowa aluwialnych i przybrzeżnomorskich utworów dolnego dewonu i eiflu (?) obszaru radomsko-lubelskiego
Autorzy:
Turnau, E.
Miłaczewski, L.
Wood, G. D.
Powiązania:
https://bibliotekanauki.pl/articles/191950.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
spore stratigraphy
Oppel zones
Lower Devonian
Eifelian
Radom-Lublin area
Polska
Opis:
The Czarnolas and Zwoleń Formations of the Terebin IG 5 borehole, and the Terrigenous suite of the Giełczew PIG 5 borehole were analyzed for their spores. Palynological slides from a previous study of the Czarnolas Formation from the Pionki 4 borehole were re-examined and re-interpreted based on new observations and recent spore zonation publications. Two new cryptospores (Cymbohilates pusillus n. sp., Cymbohilates baculatus n. sp.) and two new trilete spores (Retusotriletes niger n. sp., Retusotriletes tuberiferus n. sp.) are described and illustrated. The Lower Devonian and probable Eifelian spore assemblages are assigned to Streelispora newportensis- Emphanisporites micrornatus (NM), Verrucosisporites polygonalis-Dibolisporites wetteldorfensis (PoW), Emphanisporites foveolatus-Verruciretusispora dubia (FD), and Acinosporites apiculatus-Calyptosporites proteus (AP) Oppel zones. These zones have been recognized in the Ardenne-Rhine regions. These data can also be compared to worldwide eustatic signatures. The spore data indicate that in the Radom-Lublin area marine sedimentation ended in either late early or early late Lochkovian, and the successive flooding commenced in late Emsian, probably the serotinus chron.
Utwory dewońskie obszaru radomsko-lubelskiego występują w obrębie brzeżnej części platformy wschodnioeuropejskiej. Można tu wyróżnić wyraźne, ograniczone uskokami jednostki strukturalne, a to: wyniesiona część platformy (EPEEP), rów mazowiecko-lubelski (MLT) i wyniesienie radomsko-kraśnickie (RKU). Na ościennym terytorium Ukrainy przedłużenie wyniesionej części platformy zwane jest wyniesieniem północno-wołyńskim (NVU) i depresją południowo-wołyńską (SVD), a kontynucja rowu mazowiecko-lubelskiego nosi nazwę rowu lwowskiego (LT) (Fig. 1). Womawianym rejonie obecne są wszystkie trzy oddziały systemu dewońskiego leżące zgodnie na górnym sylurze. Ich podział biostratygraficzny jest wciąż niepełny, szczególnie jeśli chodzi o przybrzeżnomorskie i aluwialne osady nie zawierające diagnostycznej fauny. Celem niniejszej pracy jest przynajmniej częoeciowe wypełnienie tej luki. Przeprowadzone badanie palinologiczne dotyczyły formacji czarnoleskiej i zwoleńskiej z otworu Terebin IG 5 oraz serii terygenicznej z otworu Giełczew PIG 5 (Tabele 1, 2). Formacja czarnoleska i seria terygeniczna reprezentują osady przybrzeżnomorskie, zaś formacja zwoleńska osady aluwialne. Ponownie zbadano zespoły spor z formacji czarnoleskiej z otworu Pionki 4. Uzyskane przed 20 laty wyniki zostały w tej pracy reinterpretowane w oparciu o najnowsze obserwacje i nowsze publikacje dotyczące zonacji sporowej (Fig. 2). Zbadane zespoły były na ogół urozmaicone. Zawierały one zarówno kryptospory, jak i spory ze znakiem zrostowym (por. Figury 3–6). W interpretowaniu uzyskanych wyników badań posłużono się zonacją sporową stworzoną dla dewonu obszaru ardeńsko-reńskiego. Wyróżniono szereg zon Oppla oraz zon filogenetycznych lub interwałowych (Fig. 2). Górną część formacji czarnoleskiej (Terebin IG 5 i Pionki 4) zaliczono do zony Oppla Streelispora newportensis-Emphanisporites micrornatus (NM), zony filogenetycznej M (górna część dolnego lochkowu lub dolna część górnego lochkowu). Dolną część formacji zwoleńskiej (Terebin IG 5) zaliczono również do zony Oppla NM, zony ewolucyjnej Si (dolna częoeć górnego lochkowu). Górna częoeć formacji zwoleńskiej (Terebin IG 5) należy do zony Oppla Verrucosisporites polygonalis-Dibolisporites wetteldorfensis (PoW), zon interwałowych W i Su (prag, być może także najniższy ems). Seria terygeniczna (Giełczew PIG 5) należy do zon Oppla Emphanisporites foveolatus-Verruciretusispora dubia (FD) górnego emsu i Acinosporites apiculatus-Calyptosporites proteus (AP), obejmującej pogranicze ems/eifel. Uzyskane wyniki pozwalają na wysunięcie następujących stwierdzeń: 1. Górna część formacji czarnoleskiej (Pionki 4 i Terebin IG 5) reprezentuje ostatni etap sedymentacji morskiej, zakończonej w późnym wczesnym lochkowie (lub wczesnym późnym lochkowie). 2. Formacja zwoleńska (Terebin IG 5) zawiera utwory górnego lochkowu po prag lub najniższy ems. W tym rejonie brakuje znacznej części osadów emsu obecnych w rejonie Radomia (Pionki 1, 4, Ciepielów IG 1) 3. Seria terygeniczna (Giełczew PIG 5) należy do górnego emsu i (prawdopodobnie) dolnego eiflu. Początek sedymentacji morskiej w tym rejonie można datować pośrednio jako poziom konodontowy serotinus. Dolna granica tej serii odpowiada więc dolnej granicy formacji grzegorzowickiej i jej odpowiedników w Górach Świętokrzyskich. Zatem cykl transgresywnoregresywny II Narkiewicza et al. (1998) odpowiada cyklowi Ic Johnsona et al. (1985).
Źródło:
Annales Societatis Geologorum Poloniae; 2005, 75, No 2; 121-137
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New osteostracans from the Lower Devonian terrigenous deposits of Podolia, Ukraine
Autorzy:
Voichyshyn, V
Powiązania:
https://bibliotekanauki.pl/articles/20783.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Ukraine
new osteostracan
Agnatha
osteostracan
Devonian
Lower Devonian
morphology
deposit
Podolia
taxonomy
paleontology
Osteostraci
Opis:
New osteostracans (Agnatha, Osteostraci) Zenaspis dzieduszyckii sp. nov. and Wladysagitta janvieri gen. et sp. nov., as well as new form of Diademaspis are described from the Lower Devonian of Podolia (Ukraine). Among them Zenaspis dzieduszyckiisp. nov. differs from all other representatives of the genus by its smaller overall size and relatively larger orbits. Wladysagitta janvieri is remarkable by having a rostral process. This new species together with “Cephalaspis” acutirostris Stensiö, 1932 from Old Red deposits of Shropshire (Great Britain) are proposed to be united under common generic name Wladysagitta. Since Diademaspis sp. is completely unknown in outline of its shield, it could not be named as new species, although it should be a really new form. New diagnostic features, such as relative width of the orbits, relative width of the dorsal field, and the position of the posterior end of the lateral fields relatively to the margins of the headshield, are proposed to differentiate genera within the Zenaspididae. Probably, the rostral process of osteostracans should be considered as a multifunctional device having at least a sensory function for food−search, possibly hydrodynamic functions, or may play a role in scaring predators.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sedimentology of deposits from around the Late Caledonian unconformity in the western Holy Cross Mts.
Autorzy:
Malec, J.
Powiązania:
https://bibliotekanauki.pl/articles/2059319.pdf
Data publikacji:
2001
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Holy Cross Mountains
Upper Silurian-Lower Devonian
stratigraphy
sedimentology
Late Caledonian unconformity
Opis:
The Upper Silurian-Lower Devonian section of the western part of the Holy Cross Mts. is composed of greywackes of the Niewachlów Beds, Kielce Beds and Miedziana Góra Conglomerates. They are separated from the terrestrial Gruchawka Conglomerates and Barcza Beds by an erosional surface. Depositional structures recorded in the Silurian greywackes indicate the deep-water sedimentary environment of a flysch facies. The uppermost part of the Kielce Beds and the Miedziana Góra Conglomerates accumulated on a submarine delta fan. These deposits correspond to Late Caledonian molasse and are associated with closure of the Late Silurian basin in the Holy Cross Mts. The Gruchawka Conglomerates, containing fish remains, mark the beginning of the Early Devonian marine transgression. Together with the overlying sandstones and mudstones of the Barcza Beds they form the Old Red Sandstone succession. The Late Caledonian unconformity occurs between the Upper Silurian molasse deposits and Lower Devonian Old Red Sandstone facies, and the stratigraphic gap most likely spans the Pridoli, Lochkovian and lower Pragian. Large thicknesses of Silurian greywackes in the NW part of Kielce, and the high degree of thermal maturity of organic matter, indicate a geotectonic affinity of this region with the Łysogóry Block.
Źródło:
Geological Quarterly; 2001, 45, 4; 397-416
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Life strategies and function of dissepiments in rugose coral Catactotoechus instabilis from the Lower Devonian of Morocco
Autorzy:
Berkowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/20490.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
life strategy
life function
dissepiment
rugose coral
Catactotoechus instabilis
paleontology
Devonian
Lower Devonian
Morocco
Rugosa
coral
Opis:
This study focuses on the life strategies of small, dissepimented rugose coral Catactotoechus instabilis (representative of Cyathaxonia fauna) from the Emsian argillaceous deposits of mud mounds of Hamar Laghdad (Anti−Atlas, Morocco). Numerous constrictions and rejuvenescence phenomena as well as frequent deflections of growth directions among the studied specimens suggest unfavourable bottom conditions resulted from sliding down of the soft sediment on the mound slopes. Dissepimental structures observed on well−preserved calices and thin sections played an important role in the life of the coral, supporting their successful recovery after temporary burial within unstable soft sediment. The development of lonsdaleoid dissepiments, apart from being biologically controlled, was also strongly influenced by environmental factors. Such modifications in lonsdaleoid dissepiments growth were observed in phases of constrictions, rejuvenescence and deflections of growth, when their development was significantly increased in comparison to phases of their stable growth. Dissepiment morphology suggests that the process of formation of lonsdaleoid dissepiments in Catactotoechus instabilis is consistent with the hydraulic model.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lower Devonian [Emisian] rugose corals from the Cantabrian Mountains, Northern Spain
Autorzy:
Schroder, S
Soto, F.
Powiązania:
https://bibliotekanauki.pl/articles/21027.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ecology
Cantabriastraea cantabrica
Rugosa
Devonian
Lower Devonian
Tabulophyllum bonarense
rugose coral
Emsian
coral
paleontology
Spain
Cantabrian Mountains
Opis:
Two species of Lower Devonian rugose corals are described from the Cantabrian Mountains of Spain: Cantabriastraea cantabrica gen. et sp. nov. and Tabulophyllum bonarense sp. nov. The development of rootor buffer−like attachment structures (“rhizoid processes”) in T. bonarense indicates adaption to the soft substrate and supports corallite stabilisation. Because of their strongly everted calices and a corresponding arrangement of trabeculae, the colonies of the genus Cantabriastraea are assigned tentatively to the Paradisphyllinae, constituting the first record of the subfamily in Western Europe. Some specimens give information on colony−formation of this taxon, which is induced by strong lateral budding (nonparricidal increase) of a remarkable large and long−lasting protocorallite.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acanthodians from the Lower Devonian (Emsian) ‘Placoderm Sandstone’, Holy Cross Mountains, Poland
Autorzy:
Burrow, C. J.
Szrek, P.
Powiązania:
https://bibliotekanauki.pl/articles/139217.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Acanthodii
Machaeracanthus
Striacanthus
Onchus
Emsian
Lower Devonian
Polska
fałdopłetwe
akantody
ems
dewon dolny
Polska
Opis:
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.
Źródło:
Acta Geologica Polonica; 2018, 68, 3; 307-320
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stem chondrichthyan microfossils from the Lower Old Red Sandstone of the Welsh Borderland
Autorzy:
Burrow, C. J.
Turner, S.
Powiązania:
https://bibliotekanauki.pl/articles/138801.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
scale histology
palaeobiogeography
Lower Devonian
Lochkovian
stem gnatho stomes
Altholepis
Polymerolepis
British Isles
histologia
paleobiogeografia
dewon dolny
lochkov
Wyspy Brytyjskie
Opis:
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.
Źródło:
Acta Geologica Polonica; 2018, 68, 3; 321-334
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vascular structure of the earliest shark teeth
Autorzy:
Martínez-Pérez, C.
Martín-Lazaro, A.
Ferrón, H. G.
Kirstein, M.
Donoghue, P. C. J.
Botella, H.
Powiązania:
https://bibliotekanauki.pl/articles/139170.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Leonodus
Celtiberina
early chondrichthyans
Lower Devonian
synchrotron tomography
vascular system
ryby chrzęstnoszkieletowe
ryby chrzęstne
chrzęstniki
dolny dewon
tomografia
układ naczyniowy
Opis:
Here we use synchrotron tomography to characterise dental vasculature in the oldest known tooth-bearing sharks, Leonodus carlsi Mader, 1986 and Celtiberina maderi Wang, 1993. Three dimensional reconstruction of the vascular system and microstructure of both taxa revealed a complex and dense network of canals, including horizontal, ascending and secondary bifurcated canals, as well as histological features consistent with an osteodont histotype. However, L. carlsi and C. maderi also exhibit significant morphological differences, showing Leonodus a typical diplodont tooth morphology with a linguo-labially elongated base, that contrast with Celtiberina’s teeth that show a single conical cusp curved lingually with a week developed flat base mesio-distally extended, perhaps reflecting distant relationship. These data are compatible with a pre-Devonian diversification of the two main tooth types traditionally recognised in Palaeozoic sharks (i.e., “cladodont” vs “diplodont”). Finally, our data demonstrate that existing dental classification schemes based on styles of vascularisation are over-simplified, especially when Palaeozoic taxa are considered.
Źródło:
Acta Geologica Polonica; 2018, 68, 3; 457-465
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crested antiarch Bothriolepis zadonica H.D.Obrucheva from the Lower Famennian of Central European Russia
Autorzy:
Moloshnikov, S
Powiązania:
https://bibliotekanauki.pl/articles/21435.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Famennian
Lower Famennian
locality
Devonian
Bothriolepis
Bothriolepidoidei
Russia
antiarch
paleontology
Bothriolepis zadonica
Opis:
New materials on the bothriolepidid Bothriolepis zadonica H.D. Obrucheva, 1983 from the Zadonskian Regional Stage (Upper Devonian, Lower Famennian) of Central Devonian Field (Central European Russia) are described and illustrated. These materials came from nine localities in the Orel and Tver Regions of Russia. This species is characterised by the presence of a well developed median dorsal crest in the trunk armour and unusual type of the preorbital recess of the head shield; this recess is designated herein “trapezoid”. The ontogenetic and individual variations of B. zadonica are studied. The crested bothriolepidids are known only from Euramerica and East Gondwana. The possible relationships between crested bothriolepidids in these provinces are discussed.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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