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Wyszukujesz frazę "tetrapod" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Toward the origin of amniotes: Diadectomorph and synapsid footprints from the early Late Carboniferous of Germany
Autorzy:
Voigt, S.
Ganzelewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/20515.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
amniote
tetrapod
diadectomorph
footprint
Late Carboniferous
Carboniferous
paleontology
Germany
Ichniotherium
Dimetropus
Cotylosauria
tetrapod track
Opis:
Ichnotaxonomic revision of two extended sequences of large tetrapod footprints from the Westphalian A Bochum Formation of western Germany suggests assignment of the specimens to the well−known Permo−Carboniferous ichnogenera Ichniotherium and Dimetropus. Trackway parameters and imprint morphology strongly support basal diadectomorphs and “pelycosaurian”−grade synapsid reptiles, respectively, as the most likely trackmakers. The ichnofossils thereby extend the first appearance of these two important groups of basal tetrapods by about 5–10 million years, to the early Late Carboniferous, which is in accordance with the minimum age for the evolutionary origin of the clades following widely accepted phylogenetic analyses. These trackways provide not only direct evidence bearing on activity and behaviour of large terrestrial tetrapods close to the origin of amniotes, but also serve as a valuable benchmark for the assessment of controversially interpreted vertebrate tracks from other localities of similar age.
Źródło:
Acta Palaeontologica Polonica; 2010, 55, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tetrapod trace fossils from lowermost Jurassic strata of the Moenave Formation, northern Arizona, USA
Autorzy:
Tanner, L.
Lucas, S.
Powiązania:
https://bibliotekanauki.pl/articles/2061343.pdf
Data publikacji:
2008
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
burrows
tetrapod
cynodont
tritylodontid
rhizolith
Moenave
Lower Jurassic
Opis:
At Moenkopi Wash along the Ward Terrace escarpment of northern Arizona strata of the upper Dinosaur Canyon Member of the Moenave Formation contain sedimentary structures we interpret as casts of tetrapod burrows. Sandstone casts and in situ burrows occur concentrated in two horizons that extend several hundred meters along the Ward Terrace escarpment. The structures, hosted in beds of eolian sandstone, form interconnecting networks of burrows that branch at right angles. Individual burrow casts have sub-circular cross sections and consist of nearvertical tunnels and horizontal to low-angle galleries that connect to larger chambers. Most burrow casts measure 5 to 15 cm in diameter, are filled by sandstone of similar grain size as the host rock, and have walls that are unlined and lack external ornamentation. Bedding plane exposure of the lower horizon reveals that the density of burrows exceeds 30 vertical tunnels per square meter. One exposure in the upper horizon reveals burrows concentrated in a mound-like structure with 1 m of relief. Rhizoliths, distinguished from burrows by their typical smaller diameters, calcareous infilling, and downward branching, co-occur with these burrows in the upper horizon. The fossil burrows in the Moenave Formation appear to have been constructed by a fossorial tetrapod with social behavior similar to the modern Mediterranean blind mole-rat. Although no skeletal remains are associated with the burrows, the fossil record suggests that the most likely producers of the Moenave burrows were tritylodontid cynodonts.
Źródło:
Volumina Jurassica; 2008, 6, 1; 133-141
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global Jurassic tetrapod biochronology
Autorzy:
Lucas, S.
Powiązania:
https://bibliotekanauki.pl/articles/2061346.pdf
Data publikacji:
2008
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Jurassic
tetrapod
footprints
biostratigraphy
land-vertebrate faunachron
provinciality
Opis:
Jurassic tetrapod fossils are known from all of the continents, and their distribution documents a critical paleobiogeographic juncture in tetrapod evolution – the change from cosmopolitan Pangean tetrapod faunas to the provincialized faunas that characterize the late Mesozoic and Cenozoic. Two global tetrapod biochronological units (faunachrons) have been named for the Early Jurassic – Wassonian and Dawan – and reflect some Early Jurassic tetrapod cosmopolitanism. However, after the Dawan, a scattered and poorly-dated Middle Jurassic tetrapod record and a much better understood Upper Jurassic tetrapod record indicate that significant provincialization of the global tetrapod fauna had begun. Middle Jurassic tetrapod assemblages include distinct local genera of sauropod dinosaurs, which are large, mobile terrestrial tetrapods, and this suggests marked provinciality by Bajocian time. The obvious provincialism of well known Chinese Middle-Upper Jurassic dinosaur faunas also documents the end of tetrapod cosmopolitanism. The distribution of some Late Jurassic dinosaur taxa defines a province that extended from the western USA through Europe into eastern Africa. Provincial tetrapod biochronologies have already been proposed for this province and for the separate eastern Asian Late Jurassic province. Tetrapod footprints only identify two global assemblage zones, one of Early Jurassic and the other of Middle-Late Jurassic age. The incomplete state of Jurassic tetrapod biochronology reflects both an inadequate record with poor temporal constraints and a relative lack of study of the biostratigraphy of Jurassic fossil vertebrates.
Źródło:
Volumina Jurassica; 2008, 6, 1; 99-108
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Candidate sections for the GSSP of the base of the Bathonian Stage (Middle Jurassic)
Autorzy:
Fernandez-Lopez, S.
Powiązania:
https://bibliotekanauki.pl/articles/2061360.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Jurassic
tetrapod
footprints
biostratigraphy
land-vertebrate faunachron
provinciality
Opis:
In accordance with the recommendations of the International Commission on Stratigraphy (ICS), the leading candidate for the Global Boundary Stratotype Section and Point (GSSP) of the base of the Bathonian Stage is located in the Ravin du B?s (Bas Auran area, SE France). This section was formally proposed as candidate nineteen years ago. A second potential candidate section is located in the Cabo Mondego area (Portugal). This Portuguese section, however, has not been formally proposed as a candidate for the Bathonian basal boundary stratotype. The formal selection and proposal of a GSSP for the Bathonian Stage is the responsibility of the Bathonian Working Group (BtWG) and is expected by September 2007. In accordance with the procedures to ratify GSSPs, a formal ballot on the selection and proposal of a GSSP for the Bathonian Stage, by post or email, by all members of the BtWG is the responsibility of the convenor and the International Subcommission on Jurassic Stratigraphy Executive, and will be carried out within this time scale.
Źródło:
Volumina Jurassica; 2009, 7, 1; 77-88
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated stratigraphical study of the candidate Oxfordian Global Stratotype Section and Point (GSSP) at Redcliff Point, Weymouth, Dorset, UK
Autorzy:
Page, K.
Melendez, G.
Hart, M.
Price, G.
Wright, J.
Bown, P.
Bello, J.
Powiązania:
https://bibliotekanauki.pl/articles/2061363.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
burrows
tetrapod
cynodont
tritylodontid
rhizolith
Moenave
Lower Jurassic
Opis:
Ham Cliff near Redcliff Point, Weymouth, Dorset (SW England) exposes one of Europe's most complete Callovian-Oxfordian boundary sequences and has consequently been identified as a potential candidate GSSP for the base of the Oxfordian Stage. The boundary sequence lies within the thick mudrock facies of the Oxford Clay Formation and is abundantly fossiliferous, cardioceratid ammonites in particular being conspicuous. By convention, the stage boundary is drawn at the first occurrence of the genus Cardioceras here represented by C. redcliffense Page, Melendez and Wright at the base of the Scarburgense Subchronozone of the Mariae Chronozone. Associated Perisphinctoidea (including Peltoceras, Alligaticeras and Euaspidoceras) provide additional biostratigraphical information. Other macrofossil groups show less discernible changes, although frequent belemnites (Hibolithes) provide new highresolution carbon and strontium isotope data which are consistent with global curves and continuous sedimentation across the boundary interval. Magnetostratigraphic information is also available. Foraminiferal assemblages are dominated by epistominids but include a flood of early planktonic forms, including ?Globuligerina oxfordiana (Grigelis) immediately above the boundary. Well-preserved nannofloras are dominated by Watznaueria with conspicuous Zeugrhabdotus, podorhabdids and Stephanolithion indicating the NJ14 Biozone. Ostracoda and holothurian spicules are also recorded. These results are synthesised to provide a multidisciplinary, integrated review of the suitability of Redcliff Point for the definition of an Oxfordian GSSP. Correlations with the French candidate site in Haute-Provence are discussed and proposals made for formally establishing a GSSP for the base of the Oxfordian Stage in Europe.
Źródło:
Volumina Jurassica; 2009, 7, 1; 101-111
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The origins of the cochlea and impedance matching hearing in synapsids
Autorzy:
Laaß, M.
Powiązania:
https://bibliotekanauki.pl/articles/20432.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
origin
cochlea
Therapsida
Anomodontia
tympanic hearing
Permian
South Africa
synapsid
tetrapod
Opis:
The origin of tympanic hearing in early synapsids is still controversial, because little is known about their inner ear and the function of their sound conducting apparatus. Here I describe the earliest known tympanic ear in the synapsid lineage, the ear of Pristerodon (Therapsida, Anomodontia) from the Late Permian of South Africa, which was virtually reconstructed from neutron tomographic data. Although Pristerodon is not a direct ancestor of mammals, its inner ear with distinctive cochlear cavity represents a connecting link between the primitive therapsid inner ear and the mammalian inner ear. The anatomy of the sound conducting apparatus of Pristerodon and the increased sound pressure transformer ratio points to a sensitivity to airborne sound. Furthermore, the origins of the cochlea and impedance matching hearing in synapsids coincided with the loss of contact between head and substrate, which already took place at least in Late Permian therapsids even before the postdentary bones became detached from the mandible.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modes of ventilation in early tetrapods: costal aspiration as a key feature of amniotes
Autorzy:
Janis, C M
Keller, J C
Powiązania:
https://bibliotekanauki.pl/articles/21209.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
reptile
bird
skin
carbon dioxide
mammal
ventilation
anamniote
amphibian
rib
tetrapod
skull
egg
Opis:
The key difference between amniotes (reptiles, birds and mammals) and anamniotes (amphibians in the broadest sense of the word) is usually considered to be the amniotic egg, or a skin impermeable to water. We propose that the change in the mode of lung ventilation from buccal pumping to costal (rib-based) ventilation was equally, if not more important, in the evolution of tetrapod independence from the water. Costal ventilation would enable superior loss of carbon dioxide via the lungs: only then could cutaneous respiration be abandoned and the skin made impermeable to water. Additionally efficient carbon dioxide loss might be essential for the greater level of activity of amniotes. We examine aspects of the morphology of the heads, necks and ribs that correlate with the mode of ventilation. Anamniotes, living and fossil, have relatively broad heads and short necks, correlating with buccal pumping, and have immobile ribs. In contrast, amniotes have narrower, deeper heads, may have longer necks, and have mobile ribs, in correlation with costal ventilation. The stem amniote Diadectes is more like true amniotes in most respects, and we propose that the changes in the mode of ventilation occurred in a stepwise fashion among the stem amniotes. We also argue that the change in ventilatory mode in amniotes related to changes in the postural role of the epaxial muscles, and can be correlated with the evolution of herbivory.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new discosauriscid seymouriamorph tetrapod from the Lower Permian of Moravia, Czech Republic
Autorzy:
Klembara, J
Powiązania:
https://bibliotekanauki.pl/articles/20297.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Moravia
Seymouriamorpha
Boskovice Furrow
skeletal anatomy
Makowskia laticephala
new genus
Lower Permian
Permian
Czech Republic
new species
Discosauriscidae
tetrapod
paleontology
Opis:
A new genus and species, Makowskia laticephala gen. et sp. nov., of seymouriamorph tetrapod from the Lower Permian deposits of the Boskovice Furrow in Moravia (Czech Republic) is described in detail, and its cranial reconstruction is presented. It is placed in the family Discosauriscidae (together with Discosauriscus and Ariekanerpeton) on the following character states: short preorbital region; rounded to oval orbits positioned mainly in anterior half of skull; otic notch dorsoventrally broad and anteroposteriorly deep; rounded to oval ventral scales. Makowskia is distinguished from other Discosauriscidae by the following characters: nasal bones equally long as broad; interorbital region broad; prefrontalpostfrontal contact lies in level of frontal mid−length (only from D. pulcherrimus); maxilla deepest at its mid−length; suborbital ramus of jugal short and dorsoventrally broad with long anterodorsal−posteroventral directed lacrimal−jugal suture; postorbital anteroposteriorly short and lacks elongated posterior process; ventral surface of basioccipital smooth; rows of small denticles placed on distinct ridges and intervening furrows radiate from place immediately laterally to articular portion on ventral surface of palatal ramus of pterygoid (only from D. pulcherrimus); oblique anterior margin of transverse flange of pterygoid directed anteromedially−posterolaterally; cultriform process of parasphenoid relatively short and slightly rounded; ventral surface of the posterior plate of parasphenoid heavily sculptured (only from D. pulcherrimus and Ariekanerpeton); distal ends of fourth and fifth presacral ribs distinctly anteroposteriorly broadened, and extend into the hook−like, posteriorly directed processes; shaft of ?last caudal rib anteroposteriorly broadened; posterior stem of interclavicle narrows anteriorly and posteriorly from broadened mid−length section.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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