scholarly journals Description of a new genus of primitive ants from Canadian amber, with the study of relationships between stem- and crown-group ants (Hymenoptera: Formicidae)

2016 ◽  
Author(s):  
Leonid H. Borysenko
Keyword(s):  
Statistical Analysis ◽  
Morphometric Analysis ◽  
New Genus ◽  
Statistical Study ◽  
The Other ◽  
Taxonomic Position ◽  
Crown Group ◽  
Stem Group ◽  
Evolution Of Eusociality

AbstractA detailed study of the holotype ofSphecomyrma canadensisWilson, 1985 from Canadian amber has led to the conclusion that the specimen belongs to a new genus, here namedBoltonimeciagen.n. Since the taxonomy of stem-group ants is not well understood, in order to find the taxonomic position of this genus, it is necessary to review the classification of stem-group ants in a study of their relation to crown-group ants. In the absence of data for traditional taxonomic approaches, a statistical study was done based on a morphometric analysis of antennae. Scape elongation is believed to play an important role in the evolution of eusociality in ants; however, this hypothesis has never been confirmed statistically. The statistical analysis presented herein lends support to the view that antennal morphology reliably distinguishes stem-group ants from crown-group ants to determine whether a species belongs to one or the other group. This, in turn, may indicate a relationship exists between eusociality and scape elongation. A review of Cretaceous records of ants is made and the higher classification of Formicidae with definitions of stem and crown groups is proposed. Newly obtained data are discussed focusing particularly on the origin, evolution and diversity of ants.

Convergence with naticids: phenotypic phylogenetic study on some Antarctic littorinoideans, with description of the zerotulid new genusPseudonatica, and its presence in Brazil (Mollusca, Caenogastropoda)

2017 ◽  
Vol 98 (6) ◽  
pp. 1365-1381
Author(s):  
Luiz Ricardo L. Simone
Keyword(s):  
Phylogenetic Analysis ◽  
Type Species ◽  
New Genus ◽  
The Other ◽  
Taxonomic Position ◽  
Phylogenetic Study ◽  
Brazilian Coast ◽  
Antarctic Species ◽  
Oesophageal Gland ◽  
Phenotypic Characters

Some Antarctic littorinoideans have a remarkable convergence with Naticoidea in shell and operculum features. Two naticid-like species of that group are studied in their phenotypic features in order to improve their taxonomy and to discuss the meaning of that convergence, as the former are herbivore-detritivore and the latter active predatory organisms. One of the studied species is the littorinidLaevilacunaria antarctica(Martens, 1885). The other belongs to a new genus –Pseudonatica, with the type species also newly described:P. antarctica, the genus is tentatively placed in Zerotulidae. Another Pseudonatica is also described,P. ampullarica, based only on shells collected by Marion-Dufresne French expedition off Brazilian coast, this finding expands the occurrence of zerotulids northwards. Besides the similarities of shell and operculum, other structures of these Antarctic species also show singular similarities with naticoideans, such as the wide foot, the complexity of opercular attachment in pedal opercular pad, the wide oesophageal gland, and the coiled arrangement of the pallial oviduct. The phenotypic characters were coded and inserted in a previous large phylogenetic analysis on Caenogastropoda (Simone, 2011), furnishing a wide basis for discussion on the characters, taxonomic position, evolution and adaptations of these organisms.

A new genus of pollen-beetle from South Africa (Coleoptera: Nitidulidae), with discussion of the generic classification of the subfamily Meligethinae

2008 ◽  
Vol 39 (4) ◽  
pp. 419-430 ◽  
Author(s):  
◽  
Alessio de Biase ◽  
Paulo Audisio ◽  
Andrew Cline ◽  
Marco Trizzino ◽  
...  
Keyword(s):  
South Africa ◽  
Host Plants ◽  
New Genus ◽  
Taxonomic Position ◽  
Related Genus ◽  
Pollen Beetle ◽  
Larval Host ◽  
Larval Host Plants

AbstractThe pollen-beetle Sebastiangethes anthystrixoides, n.gen., n.sp. from northern South Africa is described. The taxonomic position of Sebastiangethes, the related genus Anthystrix Kirejtshuk, 1981, as well as a relatively large assemblage of partially undescribed allied African taxa is discussed in the context of the Oriental genus Cyclogethes Kirejtshuk, 1979. An informal taxonomic assemblage named “Anthystrix-complex of genera” is here introduced. The previously unknown larval host-plants of African members of this “Anthystrix-complex of genera” are identified as dioecious trees belonging to Asteraceae within the tribe Tarchonantheae (genera Tarchonanthus and Brachylaena). Concepts of the generic and subgeneric classification of the subfamily Meligethinae also are discussed.

Primagistemus gen. nov. (Acari: Prostigmata: Stigmaeidae)

Zootaxa ◽  
2002 ◽  
Vol 29 (1) ◽  
pp. 1
Author(s):  
QING-HAI FAN ◽  
ZHI-QIANG ZHANG
Keyword(s):  
New Species ◽  
New Zealand ◽  
New Genus ◽  
The Other ◽  
Taxonomic Position ◽  
Fujian Province ◽  
Adult Females ◽  
A New Species

Primagistemus gen. nov. (Acari: Stigmaeidae) is described and its taxonomic position discussed. Adult females of this new genus are distinguished from those of Agistemus by having four pairs of setae on the propodosomal shield, by lacking postocular bodies, by having three pairs of aggenital setae and by having two setae on genu II. They are also distinguished from those of Stigmaeus by the terminal eupathidia on the palptarsus mostly fused and subterminally separated into three minute prongs, by both subcapitular setae posterolaterad of the pharynx, by having only one seta on coxa II, and by lacking endopodal shields around coxae III-IV. A new species, Primagistemus wuyiensis, from leaves of Araucaria sp. in Fujian Province of China, is described and illustrated. This new species is distinguished from the other species of the genus from New Zealand, Primagistemus loadmani (Wood) comb. nov. (transferred from Stigmaeus), by the distally truncated dorsal body setae and by setal lengths.

The first fossil horntail wasp (Hymenoptera: Siricidae) from Lower Cretaceous Crato Formation in Brazil

2020 ◽  
Vol 3 (4) ◽  
pp. 382-389
Author(s):  
CORENTIN JOUAULT ◽  
JEAN-MARC POUILLON ◽  
ANDRÉ NEL
Keyword(s):  
Lower Cretaceous ◽  
New Genus ◽  
Sister Group ◽  
The Other ◽  
Northeastern Brazil ◽  
Crown Group ◽  
The Family ◽  
Group Relationships ◽  
Fossil Records ◽  
New Discovery

A new wood wasp, Cratosirex sennlaubi gen. et sp. nov., is described and figured from one specimen collected from the Lower Cretaceous Crato Formation in northeastern Brazil. This new genus is placed in the new siricid subfamily Cratosiricinae subfam. nov., based on a combination of plesiomorphic and autapomorphic characters. The presence of small and sub-equal forewing cells 1R1 and 2R1 is a synapomorphy with the extant subfamily Siricinae, absent in the other extinct subfamilies †Auliscinae and †Gigasiricinae, supporting a sister group relationships with the Siricinae. Our new discovery expands the distribution range of Siricidae fossil records, highlights the antiquity of the family, and emphasizes the need for more studies of this particular insect lineage in the Mesozoic deposits. Currently, all the representatives of the crown group of the extant Siricidae are Cenozoic.

Ossicular homologies, systematics, and phylogenetic implications of certain North American Carboniferous asteroids (Echinodermata)

2003 ◽  
Vol 77 (3) ◽  
pp. 476-489 ◽  
Author(s):  
Daniel B. Blake ◽  
Dan R. Elliott
Keyword(s):  
Body Wall ◽  
New Genus ◽  
Prey Type ◽  
The Body ◽  
Late Paleozoic ◽  
Crown Group ◽  
Phylogenetic Implications ◽  
Phylogenetic Resolution ◽  
Defensive Mechanism

Emphereaster missouriensis new genus and species, Ambigaster, new genus, and Delicaster, new genus are assigned to the Carboniferous asteroid family Neopalaeasteridae Schuchert. The neopalaeasterids are similar to but separable from the Carboniferous Monasteridae, Calliasterellidae, and Fandasteridae, n. fam., in ambulacral and other characters. The several families indicate that late Paleozoic asteroids were diverse although poorly documented.Similarities between late Paleozoic stem-group and post-Paleozoic crown-group asteroids allow argumentation on ossicular homologies. In species with only a single row of arm marginals, an earlier suggestion that certain disk ossicles are superomarginals is rejected. Enlarged proximal adambulacrals fill space on the actinal surface whereas actinal ossicles, generally lacking in Paleozoic asteroids, provide the space-filling service in crown-group asteroids.The body wall beyond the ambulacral column and accessory ossicles traditionally have been stressed in the classification of asteroids of all ages. Because of body wall homoplasies, many older taxonomic concepts do not identify monophyletic late Paleozoic clades, nor do they indicate the derivation of the crown group. Ambulacral characters in contrast are conservative through long periods of geologic time, improving phylogenetic resolution as more taxonomic data become available. Now-available ambulacral skeletal data for certain Carboniferous genera suggest membership in lineages basal to the post-Paleozoic crown group.Emphereaster missouriensis and most neopalaeasterids are stoutly constructed suggesting a defensive mechanism against durophagous chondrichthyan fish that co-occur with the holotype of Emphereaster. Abundant sponge spicules within the disk of the holotype suggest it fed on sponges, a prey type widely exploited by living asteroids.

scholarly journals A Statistical Study of the Association of DRCs with Supercells and Tornadoes

2007 ◽  
Vol 22 (6) ◽  
pp. 1191-1199 ◽  
Author(s):  
Aaron Kennedy ◽  
Jerry M. Straka ◽  
Erik N. Rasmussen
Keyword(s):  
Statistical Analysis ◽  
Statistical Study ◽  
Three Dimensional ◽  
The Future ◽  
Larger Sample ◽  
Limited Usefulness

Abstract A new three-dimensional reflectivity echo in the rear flank of supercells known as the descending reflectivity core (DRC) has been documented in the literature by Rasmussen et al. The DRC is an enhanced region of reflectivity presumed to occur in the rear-flank downdraft (RFD) of a supercell. In the four cases they studied, this feature descended with time from the rear-echo overhang at 3–6 km in height into the supercell appendage. In addition, the DRC often occurred prior to tornadogenesis. The purpose of this paper is to serve as a more thorough analysis of DRCs using a larger sample of storms. The frequency of DRCs is explored within isolated supercells with persistent rear-flank appendages, and in particular at times preceding reported tornado onset in those supercells. Of the 64 supercells included within this study, 59% produced DRCs, with 30% of these DRCs occurring within 10 min prior to 5 min after tornadogenesis. This study included 89 reported tornadoes and 71 DRCs. Statistical analysis of the dataset reveals that while DRCs are sometimes associated with tornadoes, they presently have limited usefulness for tornado nowcasting. Improvements to Weather Surveillance Radar-1988 Doppler (WSR-88D) resolution and further classification of DRCs may help discriminate between tornadic and nontornadic appendages in the future, however.

scholarly journals A new Late Eocene primate from the Krabi Basin (Thailand) and the diversity of Palaeogene anthropoids in southeast Asia

2013 ◽  
Vol 280 (1771) ◽  
pp. 20132268 ◽  
Author(s):  
Yaowalak Chaimanee ◽  
Olivier Chavasseau ◽  
Vincent Lazzari ◽  
Adélaïde Euriat ◽  
Jean-Jacques Jaeger
Keyword(s):  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Middle Eocene ◽  
Late Eocene ◽  
The Other ◽  
Crown Group ◽  
Phylogenetic Relations ◽  
Stem Group ◽  
Morphological Adaptations ◽  
Anthropoid Primates

According to the most recent discoveries from the Middle Eocene of Myanmar and China, anthropoid primates originated in Asia rather than in Africa, as was previously considered. But the Asian Palaeogene anthropoid community remains poorly known and inadequately sampled, being represented only from China, Myanmar, Pakistan and Thailand. Asian Eocene anthropoids can be divided into two distinct groups, the stem group eosimiiforms and the possible crown group amphipithecids, but the phylogenetic relationships between these two groups are not well understood. Therefore, it is critical to understand their evolutionary history and relationships by finding additional fossil taxa. Here, we describe a new small-sized fossil anthropoid primate from the Late Eocene Krabi locality in Thailand, Krabia minuta , which shares several derived characters with the amphipithecids. It displays several unique dental characters, such as extreme bunodonty and reduced trigon surface area, that have never been observed in other Eocene Asian anthropoids. These features indicate that morphological adaptations were more diversified among amphipithecids than was previously expected, and raises the problem of the phylogenetic relations between the crown anthropoids and their stem group eosimiiforms, on one side, and the modern anthropoids, on the other side.

Precise flagellar configuration of the Rhizophlyctis harderi zoospore

1992 ◽  
Vol 70 (4) ◽  
pp. 762-771 ◽  
Author(s):  
Sonali Roychoudhury ◽  
Martha J. Powell
Keyword(s):  
Key Words ◽  
New Genus ◽  
Flagellar Apparatus ◽  
The Other ◽  
Taxonomic Position ◽  
Serial Sections ◽  
Microtubular Roots

Rhizophlyctis harder is a questionable member of the genus Rhizophlyctis, and more stable and reliable characters are needed to establish the taxonomic position of this chytrid. As a source of such characters the flagellar apparatus of zoospores of R. harderi was reconstructed from serial sections, and the precise configuration was determined. The flagellar apparatus included two major microtubular roots, each with separate points of origin near the kinetosome. Root A extended laterally from one side of the kinetosome toward and around one rumposome and then continued anteriorly. The other, root B, originated between the kinetosome and secondary centriole near fibrillar connecting material and projected anteriorly into the cytoplasm. Each of these two major roots branched into two rootlets. This system of microtubular roots is more complex than that found in the flagellar apparatus of other Chytridiomycetes presently described. The structure of the flagellar apparatus and accompanying roots clearly separates this species from others in the genus Rhizophlyctis and indicates that it can be used to establish a new genus in the Chytridiales. Key words: Rhizophlyctis harderi, Chytridiales, zoospores, flagellar apparatus, ultrastructure.

scholarly journals A new fossil soldier beetle (Coleoptera, Cantharidae, Silinae) from Eocene Baltic amber

Zootaxa ◽  
2018 ◽  
Vol 4370 (2) ◽  
pp. 189 ◽  
Author(s):  
FABRIZIO FANTI ◽  
MICHAEL J. PANKOWSKI
Keyword(s):  
New Genus ◽  
Morphological Characteristics ◽  
The Other ◽  
Taxonomic Position ◽  
Baltic Amber ◽  
Lateral Margin ◽  
New Taxon ◽  
New Genus And Species

A new genus and species of fossil soldier beetle Markus karenae gen. et sp. nov. is described and illustrated from Eocene Baltic amber. Its morphological characteristics place it in the taxonomic position of the subfamily Silinae. It is characterized by a particular lateral pronotal shape with two difform processes, pronotum slightly longer than wide, with a blunt and evident angle near the basal angles, anterior and posterior margins flat and with shallow punctation, and lateral margin strongly granulose and in relief. Furthermore, each of its legs has a claw with one acute tooth at the base, except for the posterior legs where the tooth appears to be blunt. The new taxon is morphologically compared with the other fossil representatives of Silinae from Baltic amber, and with extant Palearctic genera. 

scholarly journals Traffic analysis for a parametric tactile codec

Telecom IT ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 67-76 ◽  
Author(s):  
E. Sapunova ◽  
S. Leontiev ◽  
A. Vybornova
Keyword(s):  
Statistical Analysis ◽  
Research And Development ◽  
Research Method ◽  
The Other ◽  
Practical Relevance ◽  
Research Subject ◽  
Internet Applications ◽  
Traffic Characteristics ◽  
Haptic Interactions

This article is devoted to the haptic communications types and methods. Haptic and tactile codecs were the research subject. As a research method authors engaged analysis of the current research re-sults in the area, research and development of the parametric tactile codec, as well as statistical analysis of the obtained tactile traffic. Core result. In this article authors provide a classification of the haptic interactions and tactile codes approaches. The other result of the work is a simple parametric tactile co-dec. Also, authors have found out that such type of codec created quite intensive flow of the packets of moderate size (500 bytes). Practical relevance of the result consists in the creation of the tactile co-dec that may be used for simple Tactile Internet applications. Besides that, obtained information about tactile traffic characteristics may be used to update forecasts of the global telecom traffic growth.

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