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Wyświetlanie 1-7 z 7
Tytuł:
New cranial material of the acanthothoracid placoderm Palaeacanthaspis vasta from the Lower Devonian of Podolia—phylogenetic and taxonomic significance
Autorzy:
Dupret, V.
Szaniawski, H.
Dec, M.
Szrek, P.
Powiązania:
https://bibliotekanauki.pl/articles/2082331.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Placodermi
Acanthothoraci
neurocranium
Lochkovian
Devonian
Podolia
Ukraine
Opis:
The Early Devonian vertebrates of Podolia in Ukraine are well known thanks to the material of the basal arthrodire placoderm genus Kujdanowiaspis, originally mentioned by Brotzen in 1934. The anatomical fame of Kujdanowiaspis brought by Erik Stensiö almost eclipsed the presence of the acanthothoracid placoderm Palaeacanthapsis vasta in the underlying beds, with the original material of P. vasta being less well preserved and abundant than that of Kujdanowiaspis. Here we describe a newly discovered specimen of the acanthothoracid P. vasta from the Lochkovian of Podolia (Ukraine). The specimen, although incomplete, is very well preserved in three dimensions and allows a thorough description of its external morphology, which is compared to that of Romundina stellina and other well-known Acanthothoraci. A phylogenetic analysis is performed and the acanthothoracid nature of Palaeacanthaspis is confirmed. However, the position of Palaeacanthaspis within the Acanthothoraci remains uncertain, and its resemblance with Romundina could be due to either synapomorphies or symplesiomorphies. Similarities and differences between the two forms are exposed, and lead to the lack of synonymy at the specific level. Generic synonymy is also questioned for the first time but remains equivocal.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 2; 337-347
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new assessment of the Late Devonian antiarchan fish Bothriolepis leptocheira from South Timan (Russia) and the biotic crisis near the Frasnian–Famennian boundary
Autorzy:
LUKŠEVIČS, ERVĪNS
BEZNOSOV, PAVEL
STŪRIS, VALDEMĀRS
Powiązania:
https://bibliotekanauki.pl/articles/945315.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
placodermi
diversity
variability
devonian
frasnian
famennian
russia
south timan
Opis:
The species of the Late Devonian, earliest Famennian placoderm fish Bothriolepis jeremejevi has been downranked to subspecies Bothriolepis leptocheira jeremejevi comb. nov. in a result of detailed morphological studies of the type specimens and abundant new material from the type locality of the Sosnogorsk Formation, South Timan, Komi Republic, Russia. This taxon closely resembles Bothriolepis leptocheira leptocheira from Scotland, B. leptocheira curonica from Latvia, and B. leptocheira ssp. from Severnaya Zemlya differing only in small deviations of the size, proportions and shape of some plates of the armour. The composition of vertebrate assemblages from Scotland, Latvia, and Severnaya Zemlya containing B. leptocheira demonstrates a reduced diversity of antiarch placoderm, acanthodian, and sarcopterygian fishes; however, the Sosnogorsk assemblage differs in a larger diversity containing very primitive tetrapod and diversified sarcopterygian fishes including dipnoans and porolepiforms but lacking acanthodians. Wide distribution of a single species of Bothriolepis and usually diminished diversity of vertebrates suggest that the earliest Famennian vertebrate assemblages conform the survival faunas of the latest Frasnian–earliest Famennian biotic crisis.
Źródło:
Acta Palaeontologica Polonica; 2017, 62, 1; 97-119
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Placoderms from the Lower Devonian “placoderm sandstone” of the Holy Cross Mountains, Poland with biostratigraphical and palaeobiogeographical implications
Autorzy:
SZREK, PIOTR
DUPRET, VINCENT
Powiązania:
https://bibliotekanauki.pl/articles/945951.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
placodermi
arthrodira
actinolepidoidei
palaeobiogeography
devonian
poland
holy cross mountains
Opis:
The siliciclastic sequence of the Lower Devonian of the southern part of the Holy Cross Mountains in Poland is renown for abundant vertebrate fossils, including ostracoderm, sarcopterygian, acanthodian, chondrichthyan, and placoderm remains. Study of the vertebrate assemblage from the “placoderm sandstone” from Podłazie Hill in the Holy Cross Mountains reveals that the remains belong to Kujdanowiaspis sp. among other unspecified actinolepids and brachythoracids. The Polish actinolepid material is characterised by sizes bigger than those of the Podolian specimens; this may be related to geographic variation. Owing to the proximity between Podolia and Holy Cross Mountains we suggest that Kujdanowiaspis sp. from the Holy Cross Mountains may be a refugee of some species of Kujdanowiaspis from the Lochkovian–Pragian of Podolia and/or from Spain. Some anterolateral plates provisionally assigned to Arthrodira indet. probably represent a new genus due to the high overlapping surface for median dorsal and anteroventrolateral plates.
Źródło:
Acta Palaeontologica Polonica; 2017, 62, 4; 789-800
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skamieniałości Antiarcha (Vertebrata, Placodermi) w dewonie Gór Świętokrzyskich
Fossils of Antiarcha (Vertebrata, Placodermi) in the Devonian of the Holy Cross Mountains (central Poland)
Autorzy:
Szrek, P.
Powiązania:
https://bibliotekanauki.pl/articles/2074445.pdf
Data publikacji:
2006
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Antiarcha
ryby pancerne
skamieniałość fauny
dewon
Góry Świętokrzyskie
Placodermi
Placoderm Sandstone
Devonian
Holy Cross Mountains
Opis:
The paper indicates a similarity between remains of various Palaeozoic fishes thus hindering identification of fossil of Antiarcha—rare placoderms in the Holy Cross Mountains. A comparison of the vertebrate fossil assemblage from Lode Famennian delta deposits in Latvia with that from the Lower Devonian “Placoderm Sandstone” of the Podłazie hill in the Holy Cross Mountains (Poland) shows their similarity. It indicates a fluvial (?deltaic) origin of the “Placoderm Sandstone” from Podłazie. Additionally, fragmentary antiarch plates are revealed from the Frasnian of the Wietrznia Quarry in Kielce (Holy Cross Mountains).
Źródło:
Przegląd Geologiczny; 2006, 54, 7; 610-614
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zróżnicowanie facjalne a skamieniałości późnodewońskich plakodermów w Górach Świętokrzyskich
Facies differentiation and Late Devonian placoderms fossils in the Holy Cross Mountains
Autorzy:
Szrek, P.
Powiązania:
https://bibliotekanauki.pl/articles/2074458.pdf
Data publikacji:
2006
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Placodermi
ryby pancerne
sedymentacja osadów
skamieniałość fauny
dewon
Góry Świętokrzyskie
synsedimentation tectonic
Late Devonian
facies
Holy Cross Mountains
Opis:
Main Late Devonian placoderm taxa known from the Holy Cross Mountains are characterised. The distribution of the Late Devonian placoderm fossils is described. Variation in their occurrences depend on the sedimentation environment of the rocks which contain fossils of this group. Connections between the Holy Cross Mountains placoderms development and the synsedimentary tectonic processes active in this area during the Late Devonian is discussed, and the local faunas compared to classic assemblages of the same age from Latvia.
Źródło:
Przegląd Geologiczny; 2006, 54, 6; 521-524
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new aspinothoracid arthrodire from the Late Devonian of Ohio, U.S.A.
Autorzy:
Carr, R. K.
Powiązania:
https://bibliotekanauki.pl/articles/139264.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Placodermi
new genus Hlavinichthys
new species Hlavinichthys jacksoni
Devonian
Famennian
Cleveland Shale
Ohio
USA
nowe gatunki
dewon
famen
Opis:
The Cleveland Shale fauna represents a unique view of the time after a major Devonian extinction event (Frasnian–Famenian) with the recovery of arthrodires (Placodermi) best represented by this most specious North American fauna. This time was followed by an additional event (Hangenberg Biocrisis) leading to the extinction of arthrodires (and all other placoderms). An understanding of the diversity and interrelationships of North American arthrodires can aid our understanding of this critical time in vertebrate evolution. A new aspinothoracid arthrodire Hlavinichthys jacksoni gen. et sp. nov. is described from the Late Devonian of northern Ohio, U.S.A., which adds to our knowledge of this group. It provides a point of comparison to other members of the fauna whose interrelationships are poorly known. A phylogenetic analysis supports an assignment of Hlavinichthys jacksoni gen. et sp. nov. among the aspinothoracid arthrodires. This work has drawn attention to the continued need for descriptive and phylogenetic analyses of this unique fauna. Decades old species descriptions need revision along with preparation and description of new taxa. The work on Hlavinichthys jacksoni gen. et sp. nov. here is one step in that process.
Źródło:
Acta Geologica Polonica; 2018, 68, 3; 363-379
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A preliminary note of egg-case oviparity in a Devonian placoderm fish
Autorzy:
Carr, R. K.
Jackson, G.
Powiązania:
https://bibliotekanauki.pl/articles/139073.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Devonian
Famennian
Cleveland Shale
Ohio
USA
Placodermi
Arthrodira
oviparity
egg case
Chondrichthyes
dewon
famen
ryby pancerne
tarczowce
plakodermy
zawiasowce
jajorodność
ryby chrzęstnoszkieletowe
ryby chrzęstne
chrzęstniki
Opis:
Six enigmatic fossils from the Famennian (Devonian) Cleveland Shale in Ohio, U.S.A., are interpreted here as arthrodiran (Placodermi) egg cases. Recognition as egg cases is confirmed based on the observation of layered collagen fibers. The presence of a tuberculated bone fragment preserved within one case confirms a vertebrate source. The nature of the tubercles and the unique morphology of the egg cases supports the interpretation of an arthrodiran source. Reports of Devonian egg cases are limited to either assumed chondrichthyan producers or a putative ‘egg sac’ with a morphology atypical for any vertebrate. The Cleveland Shale egg cases thus represent the first record for a non-chondrichthyan producer. Among placoderms, behaviors of a pelagic life style with obligate nesting sites, reef fishes with live birth, and estuarine and fluvial nurseries, along with eggcase oviparity testifies to the diversity of reproductive strategies. As with modern fishes these strategies may be ecologically driven and the derived and variable reproductive biology of extant chondrichthyans is actually a primitive condition among gnathostomes. One consequence of the diversity of reproductive strategies (dependent on the topology of relationships) is the independent origin of internal fertilization within placoderms, possibly suggesting external fertilization as the primitive gnathostome reproductive mode.
Źródło:
Acta Geologica Polonica; 2018, 68, 3; 381-389
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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