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Wyświetlanie 1-3 z 3
Tytuł:
Stylophoran supertrees revisited
Autorzy:
Lefebvre, B
Powiązania:
https://bibliotekanauki.pl/articles/23222.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
supertree
Echinodermata
Mitrata
Paleozoic
Calcichordata
Stylophora
Ankyroida
Cornuta
paleontology
Opis:
Supertree analysis is a recent exploratory method that involves the simultaneous combination of two or more character−based source trees into a single consensus supertree. This method was recently applied by Ruta to a fossil group of enigmatic Palaeozoic forms, the stylophoran echinoderms. Ruta’s supertree suggested that mitrates are polyphyletic and originated from paraphyletic cornutes. Re−examination of Ruta’s data matrix strongly suggests that most source trees were based on dubious homologies resulting from theory−laden assumptions (calcichordate model) or superficial similarities (ankyroid scenario). A new supertree analysis was performed using a slightly corrected version of Ruta’s original combined matrix; the 70% majority−rule consensus of 24,168 most parsimonious supertrees suggests that mitrates are monophyletic and derived from paraphyletic cornutes. A second new supertree analysis was generated to test the influence of the pruning of three taxa in some calcichordate source trees; the 70% majority−rule consensus of 3,720 shortest supertrees indicates that both cornutes and mitrates are monophyletic and derived from a Ceratocystis−like ancestor. The two new supertree analyses demonstrate the dramatic influence of the relative contributions of each initial assumption of plate homologies (and underlying anatomical interpretations), in original source trees, on the final topology of supertrees.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Morphological variability of the Caltha palustris L. complex [Ranunculaceae] in Poland
Autorzy:
Cieslak, E
Powiązania:
https://bibliotekanauki.pl/articles/58487.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
Ranunculaceae
systematics
Caltha palustris ssp.cornuta
botany
statistics
morphological variability
Caltha laeta
Caltha palustris ssp.radicans
taxonomy
Caltha palustris ssp.palustris
Caltha palustris
Opis:
The paper presents results of biosystematic analysis of the critical group of Caltha palustris L. based on 71 populations from Poland. After a preliminary statistical analysis, fourteen morphological characters (nine quantitative and five qualitative), describing size and shape of basal leaves and mature follicles as well as stem morphology, were selected for the clearest differentiation of the complex. Several groups of morphotypes were distinguished within the complex, based on the statistical analysis of this group of characters. Against this background the taxonomy of the complex is proposed. Two species - Caltha laeta Schott, Nyman and Kotschy and Caltha palustris L. - and three subspecies within C. palustris (C. p. subsp. palustris, C. p. subsp. cornuta (Schott, Nyman and Kotschy) Hegi and C. p. subsp. radicans (T.F. Forst.) Syme, were distinguished in Poland. The status of the taxa within the Polish flora is defined. The paper includes also a key for determination of the complex taxa, as well as their detailed descriptions.
Źródło:
Acta Societatis Botanicorum Poloniae; 2004, 73, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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