Search results for "Systematics"

2014

Large prosomal scent glands constitute a major synapomorphic character of the arachnid order Opiliones. These glands produce a variety of chemicals very specific to opilionid taxa of different taxonomic levels, and thus represent a model system to investigate the evolutionary traits in exocrine secretion chemistry across a phylogenetically old group of animals. The chemically best-studied opilionid group is certainly Laniatores, and currently available chemical data allow first hypotheses linking the phylogeny of this group to the evolution of major chemical classes of secretion chemistry. Such hypotheses are essential to decide upon a best-fitting explanation of the distribution of scent-g…

Are homalozoans echinoderms? An answer from the extraxial-axial theory

2000

Homalozoans include four classes of non-pentamerous Paleozoic echinoderms: Homostelea (cinctans), Ctenocystoidea (ctenoid-bearing homalozoans), Homoiostelea (solutes), and Stylophora (cornutes and mitrates). Their atypical morphologies have historically made it difficult to relate them to other classes. Therefore, their systematic positions have been represented by two hypotheses (H): as stem taxa to echinoderms (H1) or as stem taxa to chordates (H2). These conclusions rest on previous inability to recognize synapomorphies with more crownward echinoderms, resulting in a forcing of the homalozoans down the phylogenetic tree that is more artifactual than evolutionary. The Extraxial-Axial Theo…

Phylogeny and origin of Jurassic irregular echinoids (Echinodermata: Echinoidea).

2006

27 pages; International audience; A phylogenetic analysis of Jurassic irregular echinoids is realized to explore the origin and early evolution of this important subset of echinoids. The phylogeny is based on 39 characters and considers data from apical system architecture, the corona including tuberculation and spines, Aristotle's lantern, and general test shape. Results corroborate the monophyly of Irregularia, and clarify the phylogenetic interrelationships existing between the main groups of irregular echinoids. Specializations of the Aristotle's lantern, spines, tubercles and phyllodes constitute the apomorphies for different taxa, as for the whole of Irregularia. The phylogenetic sign…

Phylogeny and species limits in the Palaearctic chiffchaffPhylloscopus collybitacomplex: mitochondrial genetic differentiation and bioacoustic eviden…

1996

Nucleotide sequences of the mitochondrial cytochrome b gene (1041 bp), analysis of vocalizations and behavioural evidence from zones of contact were used to reassess the species limits and phylogenetic relationships at the species and subspecies levels in the Phylloscopus collybita complex. A new classification is proposed which recognizes four biological species. Phylloscopus brehmii (Iberia) and P. canariensis (Canary Islands) are genetically and bioacoustically highly distinct. There is no mitochondrial gene flow between them or with P. collybita. The Mountain Chiffchaff P. sindianus (with subspecies sindianus and Iorenzii) is equally distinct genetically from southwest Asian subspecies …

Venom gland and reservoir morphology in the Doryctinae and related braconid wasps (Insecta, Hymenoptera, Braconidae)

1992

Detailed venom reservoir and venom gland intima morphology has been investigated in reprsentatives of 84 genera and 10 subfamilies of Braconidae with particular reference to the Doryctinac, basal cyclostomes and related groups including the Opiinae, Alysiinae and Rogadinae sens. lat. Several new phylogenetically significant characters are described and illustrated. Extcnsivc secretory ductules on the primary venom duct is suggested as a synapomorphy for the subfamilies Braconinac, Doryctinae, Opiinae, Alysiinae and Gnamptodontinae. The presence of two separate venom gland insertions and their position beyond the spiral sculpture of the reservoir are suggested as synapomorphies for the subfa…

Genome-based analyses reveal a synonymy among Halorubrum distributum Zvyagintseva and Tarasov 1989; Oren and Ventosa 1996, Halorubrum terrestre Vento…

2020

A comparative taxonomic study of Halorubrum distributum , Halorubrum terrestre , Halorubrum arcis and Halorubrum litoreum was carried out using different approaches, 16S rRNA gene sequence analysis, multilocus sequence analysis (MLSA), phylogenomic analysis based on the comparison of the core genome, orthologous average nucleotide identity (OrthoANI), Genome-to-Genome Distance Calculator (GGDC), synteny plots and polar lipid profile (PLP). The MLSA study, using the five concatenated housekeeping genes atpB, EF-2, glnA, ppsA and rpoB′, and the phylogenomic analysis based on 1347 core translated gene sequences obtained from their genomes showed that Halorubrum distributum JCM 9100T, Halorubru…

The bryophyte flora of Lågskär - An isolated island in the Baltic Sea

2014

This study reports the bryophyte flora of Lågskär, an isolated lighthouse island in the Åland province of Finland. A total of 81 bryophyte species were found on Lågskär, including 74 moss species and seven liverwort species. Syntrichia ruraliformis is reported for the first time in Finland, whereas Ceratodon conicus was believed to be extinct in Finland and Brachythecium turgidum was considered regionally extinct from southern Finland. peerReviewed

<p><strong>A new type designation of <em>Thymus microphyllus</em>, basionym of <em>Micromeria</em> <em>micr…

2020

Micromeria Bentham (1829: sub t. 1282) (Lamiaceae) is a monophyletic and taxonomically intricate genus, represented by nearly 70 species. These are distributed from the Macaronesian-Mediterranean region to southern Africa, India, and China (Morales 1991b, Govaerts 1999, Harley et al. 2004, Bräuchler et al. 2005, 2008; Puppo & Meimberg 2015, Puppo et al. 2014, 2015).

One is not enough: On the effects of reference genome for the mapping and subsequent analyses of short-reads.

2020

Mapping of high-throughput sequencing (HTS) reads to a single arbitrary reference genome is a frequently used approach in microbial genomics. However, the choice of a reference may represent a source of errors that may affect subsequent analyses such as the detection of single nucleotide polymorphisms (SNPs) and phylogenetic inference. In this work, we evaluated the effect of reference choice on short-read sequence data from five clinically and epidemiologically relevant bacteria (Klebsiella pneumoniae, Legionella pneumophila, Neisseria gonorrhoeae, Pseudomonas aeruginosa and Serratia marcescens). Publicly available whole-genome assemblies encompassing the genomic diversity of these species…

STUDI TASSONOMICI SU ADENOSTYLES ALPINA (ASTERACEAE) IN ITALIA MERIDIONALE

Adenostyles Cass., è un genere endemico europeo, appartenente alla la tribù delle Senecioneae, e fa parte del cosidetto ‘gruppo Quadridentato’ insieme ai generi Caucasalia B. Nord., Dolichorrhiza (Pojark.) Galushko, Iranecio B. Nord. e Pojarkovia Askerova. Esso è prevalentemente distribuito in tutto il territorio alpino, ma il suo areale si estende anche alla Spagna settentrionale, Corsica (Francia) e lungo tutta la catena appenninica in Italia, comprese le montagne della Calabria e della Sicilia, Balcani e, dubitativamente, in Grecia. Nel presente studio vengono presentati i risultati sugli studi tassonomici effettuati sui taxa appartenenti al gruppo di Adenostyles alpina (Asteraceae) pres…