Search results for "Cladistics"
showing 10 items of 29 documents
LATEST CAMBRIAN CORNUTES (ECHINODERMATA: STYLOPHORA) FROM THE TAEBAEKSAN BASIN, KOREA
2005
The oldest echinoderms and first cornute stylophorans ever reported from Korea are described, based on more than 40 specimens collected from the Late Cambrian of the Taebaeksan Basin. New material doubles the number of stylophorans described from Asia and the number of specimens of Late Cambrian stylophorans recorded throughout the world. Three different cornutes are identified: Sokkaejaecystis serrata n. gen. and sp. and two genus and species indeterminate forms A and B. Sokkaejaecystis serrata and indeterminate form B are assigned to the Chauvelicystinae, while the systematic position of indeterminate form A within cornutes is difficult to assess. This new material suggests paleobiogeogra…
Phylogeny and inflorescences of Berberidaceae — a morphological survey
1995
The 13 genera of Berberidaceae are investigated morphologically and cladistically in order to examine the phylogenetic relationships among the extant taxa. Cladistic analysis of 59 morphological characters using PAUP resulted in one most parsimonious tree. In the present paper main emphasis is put on inflorescence morphological features, which contributes eight characters to the current data matrix. The analysis resulted in four major clades. Nandina has a basal position, and the next clade includes Berberis and Mahonia. Ranzania is sister genus to Jeffersonia, Diphylleia/Podophyllum and Leontice/Bongardia. These all form the sister group to a clade in which Achlys is sister taxon to Epimed…
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…
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…
A novel family of tRNA-derived SINEs in the colugo and two new retrotransposable markers separating dermopterans from primates.
2003
Abstract Short interspersed nuclear elements (SINEs) provide a near homoplasy free and copious source of molecular evolutionary markers with precisely defined character polarity. Used as molecular cladistic markers in presence/absence analyses, they represent a powerful complement to phylogenetic reconstructions that are based on sequence comparisons on the level of nucleotide substitutions. Recent sequence comparisons of large data sets incorporating a broad eutherian taxonomic sample have led to considerations of the different primate infraorders to constitute a paraphyletic group. Statistically significant support against the monophyly of primates has been obtained by clustering the flyi…
Phylogeny of the parasitic wasp subfamily Charipinae (Hymenoptera, Cynipoidea, Figitidae)
2007
The Charipinae are a major group of hyperparasitoids of Hemiptera. Here, we present the first cladistic analysis of this subfamily's internal relationships, based on 96 morphological characters of adults. The data matrix was analysed using uniformly weighted parsimony. The effects of using alternative weighting schemes were explored by performing additional searches employing implied weights criteria. One of the caveats of implied weights analysis is that it lacks an objective criterion for selecting the value of the concavity function. In the present study, differential weighting was used to explore the sensitivity of our results to the alternative assumptions made in the analysis and to s…
New articulated protospongiid sponges from the early Cambrian Chengjiang biota
2015
Sponges are among the earliest diverging crown-group animals and widely regarded as the earliest biomineralizing animals. Indeed, unambiguous hexactine sponge spicules first occur in the lowermost Cambrian strata of the Fortunian Stage. Articulated sponge skeletons interpreted as hexactinellids and demosponges have been reported from Cambrian Stage 2–3 strata at multiple localities. Articulated sponge skeletons in the Chengjiang biota (Cambrian Stage 3), however, are dominated by forms interpreted as demosponges, despite the exceptional preservation in this biota. Here, we report new articulated sponge skeletons from the Chengjiang biota, including Paradiagoniella magna n. gen. n. sp. and P…
A new Alokistocaridae Resser, 1939 (Trilobita) from the middle Cambrian of Spain
2012
A new trilobite species, Schopfaspis? graciai, from the middle Cambrian of Spain is the first member of Alokistocaridae reported from west Gondwana. A cladistic analysis of this trilobite and other Gondwanan trilobites of possible alokistocarid affinities (Schopfaspis granulosa, Chelidonocephalus anatolicus, Derikaspis toluni, Kounamkites multiformis) suggests that this family can be divided into two subfamilies: Alokistocarinae and Altiocculinae. Schopfaspis? graciai nov. sp. and Schopfaspis granulosa are assigned to the subfamily Altiocculinae laying in a more basal position than Altiocculus species. The cladistic analysis also demonstrates a possible relationship of Chelidonocephalus ana…
Evolutionary history of treecreeper vocalisations (Aves: Certhia)☆
2008
AbstractSince the vocalisations of passerine birds are in general a good means to separate taxa when external morphological differences are few, song and call recordings of 33 treecreeper (Certhia) taxa were sonagraphed and their parameters analysed. The vocalisations show low intra-individual and intra-population variation. Phylogenetic evolutionary units at the population level were delimited by time, frequency and syntax parameters by means of principal-component and discriminant analyses. Traits of territorial song were traced on a phylogenetic tree based on cytochrome b sequences, and a mean acoustic character difference was calculated. All presently recognised nine species could be di…
Revision of the genus Trogulus Latreille: the Trogulus coriziformis species-group of the western Mediterranean (Opiliones:Trogulidae)
2008
Within the well researched European fauna of harvestmen, the genus Trogulus Latreille exhibits unexpectedly high cryptic diversity. The species’ uniform morphology hinders an exclusively morphological approach to their systematics and taxonomy, and a preliminary molecular study estimated the number of species to be three times higher than currently known. The current study focuses on a clearly defined species-group within Trogulus, combining molecular (~1700 bp 28S rRNA and the cytochrome b gene), distributional, morphometric and morphological data. Relationships are reconstructed using Bayesian inference, maximum parsimony and maximum likelihood and this information is subsequently used t…