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Wyszukujesz frazę "Ruta, M." wg kryterium: Autor


Wyświetlanie 1-3 z 3
Tytuł:
A species-level supertree for stylophoran echinoderms
Autorzy:
Ruta, M
Powiązania:
https://bibliotekanauki.pl/articles/21770.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
stylophoran
Echinodermata
Lobocarpus
Diamphidiocystis
Mitrata
source tree
Stylophora
echinoderm
paleontology
Cornuta
Opis:
The construction of supertrees from smaller, character−based cladograms permits simultaneous inclusion of a large number of taxa in a single analysis, summarizes patterns of relationships from many independent data sources, and highlights areas of conflict to be targeted by character matrix studies. The method is applied for the first time to stylophoran echinoderms (cornutes and mitrates). Published cladistic analyses of this problematic group are used to build a supertree of 77 species. Key areas of stylophoran phylogeny to be addressed by future studies include the systematic placement of several mitrate−like cornutes, the affinities of peltocystidan and lagynocystid mitrates, and the position of such bizarre−looking taxa as Diamphidiocystis and Lobocarpus. A strict consensus of 72,278 equally parsimonious supertree solutions shows cornutes to be paraphyletic relative to mitrates. Lobocarpusis either one of the most derived cornutes or the sister taxon to all mitrates, in agreement with its chimaera−like combination of cornute− and mitrate−like features. Chinianocarpos is basal to peltocystidan rather than to mitrocystitidan mitrates. Nanocarpus, an almost bilaterally symmetrical taxon previously allied to cornutes, is nested within mitrates as sister taxon to mitrocystitids plus anomalocystitids. Diamphidiocystis and Lagynocystis cause loss of phylogenetic resolution among derived mitrocystitids and basal anomalocystitids.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The brachyopoid Hadrokkosaurus bradyi from the early Middle Triassic of Arizona, and a phylogenetic analysis of lower jaw characters in temnospondyl amphibians
Autorzy:
Ruta, M.
Bolt, J.R.
Powiązania:
https://bibliotekanauki.pl/articles/21195.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachyopoid
Hadrokkosaurus bradyi
Early Middle Triassic
Triassic
Arizona
phylogenetic analysis
lower jaw
temnospondyl amphibian
amphibian
Temnospondyli
Chigutisauridae
evolution
paleontology
holotype
Opis:
The holotype of the brachyopoid temnospondyl Hadrokkosaurus bradyi, represented by a right lower jaw ramus, is re−examined based upon new data and revision of various morphological features. Additional fragmentary jaw material referred to this species is briefly described. Prominent features are a large postsymphyseal foramen that is anteriorly open, and prearticular and surangular buttresses for support of the articular. Brachyopoid characters include a long and robust postglenoid area formed by surangular and prearticular, anterior and posterior keels on at least some marginal dentary teeth, and subtriangular outline of the adductor fossa in dorsal view. Five features of the holotype ramus, long thought to be at odds with its brachyopoid or temnospondyl nature, are critically re−evaluated. A phylogenetic analysis of lower jaw characters in temnospondyls retrieves most of the clades found in more comprehensive data sets, but the statistical node support is low. Brachyopoids are monophyletic, with Hadrokkosaurus emerging as their most basal taxon.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fossil record of early tetrapods: Worker effort and the end-Permian mass extinction
Autorzy:
Bernard, E L
Ruta, M.
Tarver, J.E.
Benton, M.J.
Powiązania:
https://bibliotekanauki.pl/articles/21312.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
It is important to understand the quality of the fossil record of early tetrapods (Tetrapoda, minus Lissamphibia and Amniota) because of their key role in the transition of vertebrates from water to land, their dominance of terrestrial faunas for over 100 million years of the late Palaeozoic and early Mesozoic, and their variable fates during the end−Permian mass extinction. The first description of an early tetrapod dates back to 1824, and since then discoveries have occurred at a rather irregular pace, with peaks and troughs corresponding to some of the vicissitudes of human history through the past two centuries. As expected, the record is dominated by the well−sampled sedimentary basins of Europe and North America, but finds from other continents are increasing rapidly. Comparisons of snapshots of knowledge in 1900, 1950, and 2000 show that discovery of new species has changed the shape of the species−level diversification curve, contrary to earlier studies of family−level taxa. There is, however, little evidence that taxon counts relate to research effort (as counted by numbers of publications), and there are no biasing effects associated with differential study of different time intervals through the late Palaeozoic and Mesozoic. In fact, levels of effort are apparently not related to geological time, with no evidence that workers have spent more time on more recent parts of the record. In particular, the end−Permian mass extinction was investigated to determine whether diversity changes through that interval might reflect worker effort: it turns out that most records of early tetrapod taxa (when corrected for duration of geological series) occur in the Lower Triassic.
Źródło:
Acta Palaeontologica Polonica; 2010, 55, 2; 229-239
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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