scholarly journals A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa: Echinodermata) and its bearing on the evolution of early crinoids

2018 ◽  
Author(s):  
Sarah L. Sheffield ◽  
Colin Sumrall

Recent debates over the evolutionary relationships of early echinoderms have relied heavily on morphological evidence from the feeding ambulacral system. Eumorphocystis, a Late Ordovician diploporitan, has been a focus in these debates because it bears ambulacral features that show strong morphological similarity to early crinoid arms. Undescribed and well-preserved specimens of Eumorphocystis from the Bromide Formation (Oklahoma, USA) provide new data illustrating that composite arms supported by a radial plate that bear a triserial arrangement of axial and extraxial components encasing a coelomic extension can also be found in blastozoans. Previous reports have considered these arm structures to be restricted to only crinoids; these combined features have not been previously observed in blastozoan echinoderms. Phylogenetic analyses suggest that Eumorphocystis and crinoids are sister taxa and that shared derived features of these taxa are homologous. This evidence concerning Eumorphocystis’ arms suggests that crinoid arms were derived from a specialized blastozoan ambulacral system that lost feeding brachioles and strongly suggests that crinoids are nested within blastozoans.

2013 ◽  
Vol 87 (6) ◽  
pp. 1107-1128 ◽  
Author(s):  
David F. Wright ◽  
Alycia L. Stigall

The orthidine brachiopod generaPlaesiomysandHebertellaare significant constituents of Late Ordovician benthic marine communities throughout Laurentia. Species-level phylogenetic analyses were conducted on both genera to inform systematic revisions and document evolutionary relationships. Phylogenetic analyses combined discrete and continuous characters, from which character states were determined using a statistical approach, and utilized both cladistic and Bayesian methodologies.Plaesiomys cutterensis,P. idahoensis, andP. occidentalisare herein recognized as distinct species rather than subspecies ofP. subquadratus. Similarly,Hebertella montoyensisandH. prestonensisare recognized as distinct species separate fromH. occidentalis, andH. richmondensisis recognized as a distinct species rather than a geographical variant ofH. alveata.Hebertella subjugatais removed from its tentative synonymy withH. occidentalisand revalidated.The development of species-level evolutionary hypotheses forPlaesiomysandHebertellaprovides a detailed framework for assessing evolutionary and paleobiogeographic patterns of Late Ordovician brachiopods from Laurentia. The geographic range ofHebertellaexpanded throughout Laurentia during the Richmondian into both intracratonic and marginal basins.Plaesiomys subquadratusparticipated in the Late Ordovician Richmondian Invasion. The recovered phylogenetic topology forPlaesiomyssuggests thatP. subquadratusmay have migrated into the Cincinnati region from a basin situated to the paleo-northeast.


2019 ◽  
Vol 44 (4) ◽  
pp. 930-942
Author(s):  
Geraldine A. Allen ◽  
Luc Brouillet ◽  
John C. Semple ◽  
Heidi J. Guest ◽  
Robert Underhill

Abstract—Doellingeria and Eucephalus form the earliest-diverging clade of the North American Astereae lineage. Phylogenetic analyses of both nuclear and plastid sequence data show that the Doellingeria-Eucephalus clade consists of two main subclades that differ from current circumscriptions of the two genera. Doellingeria is the sister group to E. elegans, and the Doellingeria + E. elegans subclade in turn is sister to the subclade containing all remaining species of Eucephalus. In the plastid phylogeny, the two subclades are deeply divergent, a pattern that is consistent with an ancient hybridization event involving ancestral species of the Doellingeria-Eucephalus clade and an ancestral taxon of a related North American or South American group. Divergence of the two Doellingeria-Eucephalus subclades may have occurred in association with northward migration from South American ancestors. We combine these two genera under the older of the two names, Doellingeria, and propose 12 new combinations (10 species and two varieties) for all species of Eucephalus.


2019 ◽  
Vol 11 (10) ◽  
pp. 2824-2849 ◽  
Author(s):  
Paweł Mackiewicz ◽  
Adam Dawid Urantówka ◽  
Aleksandra Kroczak ◽  
Dorota Mackiewicz

Abstract Mitochondrial genes are placed on one molecule, which implies that they should carry consistent phylogenetic information. Following this advantage, we present a well-supported phylogeny based on mitochondrial genomes from almost 300 representatives of Passeriformes, the most numerous and differentiated Aves order. The analyses resolved the phylogenetic position of paraphyletic Basal and Transitional Oscines. Passerida occurred divided into two groups, one containing Paroidea and Sylvioidea, whereas the other, Passeroidea and Muscicapoidea. Analyses of mitogenomes showed four types of rearrangements including a duplicated control region (CR) with adjacent genes. Mapping the presence and absence of duplications onto the phylogenetic tree revealed that the duplication was the ancestral state for passerines and was maintained in early diverged lineages. Next, the duplication could be lost and occurred independently at least four times according to the most parsimonious scenario. In some lineages, two CR copies have been inherited from an ancient duplication and highly diverged, whereas in others, the second copy became similar to the first one due to concerted evolution. The second CR copies accumulated over twice as many substitutions as the first ones. However, the second CRs were not completely eliminated and were retained for a long time, which suggests that both regions can fulfill an important role in mitogenomes. Phylogenetic analyses based on CR sequences subjected to the complex evolution can produce tree topologies inconsistent with real evolutionary relationships between species. Passerines with two CRs showed a higher metabolic rate in relation to their body mass.


2021 ◽  
Author(s):  
Mónica Núñez-Flores ◽  
Daniel Gomez-Uchida ◽  
Pablo J. López-González

Thouarella Gray, 1870, is one of the most speciose genera among gorgonians of the family Primnoidae (Cnidaria:Octocorallia:Anthozoa), being remarkably diverse in the Antarctic and sub-Antarctic seafloor. However, their diversity in the Southern Ocean is likely underestimated. Phylogenetic analyses of mitochondrial and nuclear DNA markers were integrated with species delimitation approaches as well as morphological colonial and polyps features and skeletal SEM examinations to describe and illustrate three new species within Thouarella, from the Weddell Sea, Southern Ocean: T. amundseni sp. nov., T. dolichoespinosa sp. nov. and T. pseudoislai sp. nov. Our species delimitation results suggest, for the first time, the potential presence of Antarctic and sub-Antarctic cryptic species of primnoids, based on the likely presence of sibling species within T. undulata and T. crenelata. With the three new species here described, the global diversity of Thouarella has increased to 41 species, 15 of which are endemic to the Antarctic and sub-Antarctic waters. Consequently, our results provide new steps for uncovering the shelf benthonic macrofauna’s hidden diversity in the Southern Ocean. Finally, we recommend using an integrative taxonomic framework in this group of organisms and species delimitation approaches because the distinctions between some Thouarella species based only on a superficial examination of their macro- and micromorphological features is, in many cases, limited.


2009 ◽  
Vol 34 (1) ◽  
pp. 102-114 ◽  
Author(s):  
M. A. Bello ◽  
A. Bruneau ◽  
F. Forest ◽  
J. A. Hawkins

The order Fabales, including Leguminosae, Polygalaceae, Quillajaceae and Surianaceae, represents a novel hypothesis emerging from angiosperm molecular phylogenies. Despite good support for the order, molecular studies to date have suggested contradictory, poorly supported interfamilial relationships. Our reappraisal of relationships within Fabales addresses past taxon sampling deficiencies, and employs parsimony and Bayesian approaches using sequences from the plastid regions rbcL (166 spp.) and matK (78 spp.). Five alternative hypotheses for interfamilial relationships within Fabales were recovered. The Shimodaira-Hasegawa test found the likelihood of a resolved topology significantly higher than the one calculated for a polytomy, but did not favour any of the alternative hypotheses of relationship within Fabales. In the light of the morphological evidence available and the comparative behavior of rbcL and matK, the topology recovering Polygalaceae as sister to the rest of the order Fabales with Leguminosae more closely related to Quillajaceae + Surianaceae, is considered the most likely hypothesis of interfamilial relationships of the order. Dating of selected crown clades in the Fabales phylogeny using penalized likelihood suggests rapid radiation of the Leguminosae, Polygalaceae, and (Quillajaceae + Surianaceae) crown clades.


Zootaxa ◽  
2017 ◽  
Vol 4254 (5) ◽  
pp. 537 ◽  
Author(s):  
CHIA-HSUAN WEI ◽  
SHEN-HORN YEN

The Epicopeiidae is a small geometroid family distributed in the East Palaearctic and Oriental regions. It exhibits high morphological diversity in body size and wing shape, while their wing patterns involve in various complex mimicry rings. In the present study, we attempted to describe a new genus, and a new species from Vietnam, with comments on two assumed congeneric novel species from China and India. To address its phylogenetic affinity, we reconstructed the phylogeny of the family by using sequence data of COI, EF-1α, and 28S gene regions obtained from seven genera of Epicopeiidae with Pseudobiston pinratanai as the outgroup. We also compared the morphology of the new taxon to other epicopeiid genera to affirm its taxonomic status. The results suggest that the undescribed taxon deserve a new genus, namely Mimaporia gen. n. The species from Vietnam, Mimaporia hmong sp. n., is described as new to science. Under different tree building strategies, the new genus is the sister group of either Chatamla Moore, 1881 or Parabraxas Leech, 1897. The morphological evidence, which was not included in phylogenetic analyses, however, suggests its potential affinity with Burmeia Minet, 2003. This study also provides the first, although preliminary, molecular phylogeny of the family on which the revised systematics and interpretation of character evolution can be based. 


2021 ◽  
Vol 6 (1) ◽  
pp. 761
Author(s):  
Eszter Ótott-Kovács

Turkish and Bulgarian both have “double evidential” constructions, which seem to contain reiterated evidential morphemes. This paper, focusing on Turkish data, shows that despite the morphological similarity between the indirect evidential -mIş and the “second” -mIş, double evidentials are not an instance of reduplication. Instead, I propose based on morphological evidence (separability of suffixes, morphological spell-out of related Turkic languages) and semantic evidence (the “second” -mIş introduces a new indexical, the Evaluator) that the second -mIş is the spell-out of a distinct syntactic head, which I call Dubitative.


Phytotaxa ◽  
2021 ◽  
Vol 484 (3) ◽  
pp. 291-297
Author(s):  
XINYU XU ◽  
CHANG-CHUN DING ◽  
WENQI HU ◽  
XIA YU ◽  
YU ZHENG ◽  
...  

A new species of Cymbidium (Orchidaceae), Cymbidium xichouense, from Yunnan Province, China, is described and illustrated based on morphological evidence and molecular analyses. The new orchid is morphologically similar to C. qinbeiense, but it has several morphological features that distinguish it from C. qiubeinense and all other recognized species in Cymbidium. Phylogenetic analyses based on nuclear (ITS) and plastid DNA (matK) were conducted, and the results also supported the status of C. xichouense as a new species, which is sister to C. qiubeiense.


2019 ◽  
Vol 44 (4) ◽  
pp. 737-752 ◽  
Author(s):  
Weston L. Testo ◽  
Ashley R. Field ◽  
Emily B. Sessa ◽  
Michael Sundue

Abstract—The taxonomy of the Polypodiaceae subfamily Microsoroideae is highly problematic, especially with respect to the circumscription of the highly variable and non-monophyletic genus Microsorum. Using phylogenetic analyses and morphological evidence, we demonstrate that sixteen taxa typically treated in the genera Microsorum and Colysis are not closely related to those groups and instead belong to three clades that are successive sister groups to the Old-World ant-fern genus, Lecanopteris. We use the available genus name Dendroconche for one of these clades and propose the new genera Bosmania and Zealandia to accommodate the remaining two groups. We provide a description and identify morphological synapomorphies for each of the genera, make new combinations and designate lectotypes where necessary, and present keys and descriptions for all relevant species. We also discuss the evolution of ant-fern associations in the lecanopteroid ferns and highlight the need for additional taxonomic work in the subfamily. The following new combinations are provided: Bosmania lastii, B. leandriana, B. membranacea, Dendroconche ampla, D. latilobata, D. linguiforme, D. sayeri, D. scandens, D. varians, Zealandia novae-zealandiae, Z. powellii, Z. pustulata, Z. pustulata subsp. howensis, and Z. vieillardii.


MycoKeys ◽  
2018 ◽  
Vol 35 ◽  
pp. 27-39 ◽  
Author(s):  
Hai-Sheng Yuan ◽  
Xu Lu ◽  
Cony Decock

Grammatuslabyrinthinusgen. et sp. nov. is proposed based on DNA sequences data and morphological characteristics. It is known so far from southern, tropical China. The new species is characterised by an annual, resupinate basidiocarp with a shallow, subporoid hymenophore, a hymenium restricted to the bottom of the tubes, a dimitic hyphal system, presence of encrusted skeletocystidia and dendrohyphidia, longitudinally septate basidia and smooth, oblong-ellipsoid to cylindrical, acyanophilous basidiospores. Phylogenetic analyses based on ITS + nLSU DNA sequences data indicate that G.labyrinthinus belongs to Auriculariaceae in which it has an isolated position. Phylogenetic inferences show G.labyrinthinus to be related to Heteroradulum. However, the ITS sequences similarity between G.labyrinthinus and H.kmetii, the type species of Heteroradulum, were 89.84% and support the establishment of the new genus. Inversely, Heteroradulumsemis clustered with G.labyrinthinus with strong support and it is transferred to Grammatus.


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