Search results for "phylogenetic"
showing 10 items of 1179 documents
The Global Soil Mycobiome consortium dataset for boosting fungal diversity research
2021
This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at https://doi.org/10.1007/s13225-021-00493-7. Fungi are highly important biotic components of terrestrial ecosystems, but we still have a very limited understanding about their diversity and distribution. This data article releases a global soil fungal dataset of the Global Soil Mycobiome consortium (GSMc) to boost further research in fungal diversity, biogeography and macroecology. The dataset comprises 722,682 fu…
A critical comment on ‘ankyroids’ (Echinodermata, Stylophora)
2001
Abstract A recent cladistic analysis of stylophoran echinoderms performed by Parsley suggested that mitrates are polyphyletic and derived from symmetrical cornutes. Parsley erected the order Ankyroida to include all derived cornutes and mitrates. The present paper addresses several significant problems in the data matrix of Parsley's cladistic analysis. Detailed morphological comparisons of various stylophorans suggest that important homologies have been ignored: cornute zygal crest and mitrate septum, adorals, glossal and digital. Subanals are not homologous in mitrates. Identification of plate homologies shows that similar-looking symmetrical thecal outlines have been acquired independent…
Early oysters and their supposed Permian ancestors
2005
The origin of oysters is a much debated palaeontological issue. Recent morphological studies indicate that oysters are characterized by a particular ribbing pattern, the so-called antimarginal ribs which are characterized by a proper morphogenetic pattern. Therefore antimarginal ribs can be used as a diagnostic character in phylogeny. The earliest recognized bivalve displaying diagnostic features of oysters (sinistral attachment to the substrate, typical hinge and ligament structure, and antimarginal ribs) is Ostracites cristadifformis Schlotheim, 1820 first appearing in the Anisian of Europe. This common species was later attributed to Enantiostreon and is here transferred to Umbrostrea. S…
Tremadocian Stylophoran Echinoderms From The Taebaeksan Basin, Korea.
2006
15 pages; International audience; Abundant isolated elements of cornute and mitrate stylophorans were recovered from the upper Tremadocian Tumugol Formation in the Taebaeksan Basin, Korea. Cornute skeletal elements comprise a diverse assemblage of marginals and brachials of cothurnocystid affinities, suggesting the presence of no fewer than four different species. Mitrate remains include numerous isolated adorals, marginals, and aulacophoral plates with typical peltocystidan morphologies. Two adorals are identified as Anatifopsis sp., while all the others are attributable to A. cocaban. However, the two previously documented peltocystidans of Korea, A. cocaban and A. truncata, are sufficien…
Pseudodalatias henarejensisnov. sp. a new pseudodalatiid (Elasmobranchii) from the Middle Triassic of Spain
2009
ABSTRACT Pseudodalatiids, a chondrichthyan family of uncertain phylogenetic affinities, have been hitherto exclusively known from the tooth-based species Pseudodalatias barnstonensis (Sykes, 1971), which has a stratigraphic range restricted to the Upper Triassic of Europe. Pseudodalatias presents a characteristic dentition which allows it to hold and cut its prey, showing a neoselachian design, but lacking the triple-layered enameloid microstructure of neoselachian teeth. The discovery of Pseudodalatias henarejensis nov. sp. in the Ladinian of Spain extends the stratigraphical range and the palaeogeographical distribution of this family. This new species also demonstrates that a cutting-clu…
ABNORMALITIES IN THE LOWER ORDOVICIAN CORNUTE PHYLLOCYSTIS THORAL, 1935 (ECHINODERMATA: STYLOPHORA) FROM MONTAGNE NOIRE (SOUTHERN FRANCE): IMPLICATIO…
2007
9 pages; International audience; Two specimens of the cornute Phyllocystis crassimarginata Thoral, 1935 from the Lower Ordovician of Southern Montagne Noire (Languedoc, France) showing abnormal numbers of marginal plates are described. The first one (UM 310) is characterized by the insertion of one extra plate between the fourth right marginal and the zygal plate Z. Comparison with a new, undescribed Tremadoc boot-shaped cornute suggests that 1) the extra plate of UM 310 is equivalent to M4, and 2) the three right marginals located between M1 and Z in ‘‘normal'' specimens of Phyllocystis can be identified as M2, Mc, and M3. Plate configurations of the right thecal margin are thus identical …
Reconstitution du squelette d'astérides fossiles à partir d'ossicules isolés : intérêt taxinomique et phylogénétique
1999
Abstract Dissociated ossicles of asteroids are frequent in neritic sediments. Until now, this material was mainly used in the identification of species. A new method, associating a morphological analysis and counting of plates, allows the architecture of the skeleton and the shape of the body to be reconstructed. This method provides new elements for taxonomic and phylogenetic comparisons. It also provides indications on the adaptation of the asteroids to their environment. In geological beds, frequencies of the different kinds of plates will allow qualification of bioerosion and taphonomic sorting.
On the Fractal Structure of Evolutionary Trees
2002
We analyse in terms of a fractal tree the time sequences of major evolutionary leaps at various scales: from the scale of the “global” tree of life (appearance of life to homeothermy), to the distinct scales of organization of clades, such as sauropod and theropod dinosaurs, North American equids, rodents, primates including hominids, and echinoderms. We also apply this type of model to the acceleration observed in the economic crisis/no-crisis pattern in Western and pre-Columbian civilizations. In each case we find that these data are consistent with a log-periodic law of acceleration or deceleration, to a high level of statistical significance. Such a law is characterized by a critical ep…
Neoendemic ground beetles and private tree haplotypes: two independent proxies attest a moderate last glacial maximum summer temperature depression o…
2011
Abstract Previous findings regarding the Last Glacial Maximum LGM summer temperature depression (maxΔT in July) on the Tibetan Plateau varied over a large range (between 0 and 9 °C). Geologic proxies usually provided higher values than palynological data. Because of this wide temperature range, it was hitherto impossible to reconstruct the glacial environment of the Tibetan Plateau. Here, we present for the first time data indicating that local neoendemics of modern species groups are promising proxies for assessing the LGM temperature depression in Tibet. We used biogeographical and phylogenetic data from small, wingless edaphous ground beetles of the genus Trechus , and from private junip…
Les ammonites du Pliensbachien et du Toarcien basal dans la carrière de la Roche Blain (Fresnay-le-Puceux, Calvados, Basse-Normandie, France). Taxono…
2008
65 pages; International audience; Résumé Ce travail étudie les riches faunes d'ammonites du Pliensbachien et de la base du Toarcien dans la localité très fossilifère de la carrière de la Roche Blain (Calvados). Une cinquantaine d'espèces pliensbachiennes, récoltées dans une douzaine de niveaux distincts sont toutes décrites et illustrées. Leur préservation est parfois remarquable. Des structures fragiles comme les péristomes ou les mégastries sont assez souvent préservées. A l'exception de deux spécimens d'affinités téthysiennes (Arieticeras cf. amalthei (Oppel, 1853) et Dactylioceras (Eodactylites) sp.), les ammonites récoltées à la Roche Blain se rattachent toutes, sans ambiguïté, aux fau…