scholarly journals <i>Kirkbyites</i> Johnson, an ostracod genus indicative of pelagic palaeo-environments

1992 ◽  
Vol 11 (2) ◽  
pp. 229-231
Author(s):  
Gerhard Becker ◽  
Horst Blumenstengel
Keyword(s):  
Central Europe ◽  
Type Species ◽  
Upper Devonian ◽  
Low Energy ◽  
The Other ◽  
Harz Mountains ◽  
Upper Carboniferous ◽  
Early Upper

Abstract. A third Kirkbyites species, K. hercynicus sp. nov., is described from the early Upper Devonian (early Famennian) of the Harz Mountains (Central Europe) to join the other two known species of the genus Kirkbyites upsoni Johnson, the Upper Carboniferous type species from Nebraska (U.S.A.), and the late Upper Devonian Kullmannissites? solus Becker from N Spain (W Europe). Its biotype indicative carapace features, characteristic of marine low-energy palaeo-environments, place Kirkbyites Johnson, 1936 (Ostracoda, Palaeocopida, Kirkbyacea, Amphissitidae) into Becker’s “Thuringian” ecotype.

scholarly journals On Making of Micoquian Bifacial Backed Tools at Pietraszyn 49a, SW Poland

2020 ◽  
Author(s):  
Andrzej Wiśniewski ◽  
Marcin Chłoń ◽  
Marcel Weiss ◽  
Katarzyna Pyżewicz ◽  
Witold Migal
Keyword(s):  
Central Europe ◽  
Narrow Range ◽  
Comprehensive Analysis ◽  
Structured Data ◽  
The Other ◽  
Upper Palaeolithic ◽  
Data Set ◽  
Sw Poland ◽  
Marine Isotope Stage 3 ◽  
Early Upper

Abstract This paper attempts to show that manufacture of Micoquian bifacial backed tools was structured. Data for this study were collected using a comprehensive analysis of artefacts from the site Pietraszyn 49a, Poland, which is dated to the beginning of Marine Isotope Stage 3. Based on the whole data set, it was possible to distinguish four stages of the manufacturing process. During manufacturing, both mineral hammer and organic hammer were used. The tools were usually shaped due to distinct hierarchization of faces. The study has also shown that the shape of bifacial tools from Pietraszyn 49a is very similar to the other Micoquian examples from central Europe. The ways of shaping of some tools are finding their counterparts also in the Early Upper Palaeolithic inventories, but the similarities are rather limited to the narrow range of preparation of bifacial form.

Mandibles of rhizodontids: anatomy, function and evolution within the tetrapod stem-group

2002 ◽  
Vol 93 (3) ◽  
pp. 255-276 ◽  
Author(s):  
Jonathan E. Jeffery
Keyword(s):  
North America ◽  
Upper Devonian ◽  
The Other ◽  
Northern Europe ◽  
Muscle Attachment ◽  
Upper Carboniferous ◽  
Stem Group ◽  
Stem Lineage ◽  
Dorsal Process ◽  
Predatory Fishes

ABSTRACTThe Rhizodontida (Pisces: Sarcopterygii) is a clade of predatory fishes from the Upper Devonian (Aztecia; ?Givetian of Antarctica) through to the Upper Carboniferous (Strepsodus; Moscovian of northern Europe and North America). They form the most basal plesion within the tetrapod stem-lineage. The mandibles were dominated by large symphysial tusks on the dentary. Not much else is known of the mandibles in primitive rhizodontids. However, later forms show several derived characters: the mandible is very deep dorsoventrally and narrow linguolabially; the coronoid fangs bear only a single fang and no other dentition; the Meckelian element was unossified, leaving the adductor fossa unfloored by bone; the prearticular produced a large dorsal process lingual to the adductor fossa, presumably for muscle attachment. These and other characters are discussed in the context of the evolution of the tetrapod stem-group.The mandible appears to have been split into two functional units, one comprising the firmly sutured prearticular, coronoids and dentary, the other comprising the firmly sutured infradentaries. The connection between the two units was weak, suggesting a longitudinal intramandibular hinge. The possibility that this acted as a ‘torsion grip’ during feeding is discussed.

On the presence of Anchistioides willeyi (Borradaile, 1899) (Decapoda: Caridea: Anchistioididae) in the Red Sea

Zootaxa ◽  
2009 ◽  
Vol 2243 (1) ◽  
pp. 53-56 ◽  
Author(s):  
IVAN MARIN
Keyword(s):  
Red Sea ◽  
Type Species ◽  
Specific Form ◽  
The Other ◽  
Valid Species ◽  
Caribbean Region ◽  
Western Atlantic ◽  
Abdominal Somite ◽  
Single Genus ◽  
Pacific Species

The palaemonoid family Anchistioididae Borradaile, 1915 includes a single genus Anchistioides Paulson, 1875 with four known valid species: Anchistioides compressus Paulson, 1875 (type species), A. willeyi (Borradaile, 1899), A. australiensis (Balss, 1921) and A. antiguensis (Schmitt, 1924). Borradaile (1915) suggested two more species within the genus Amphipalaemon Nobili, 1901 (a junior synonym of Anchisitioides Paulson), Amphipalaemon gardineri Borradaile, 1915 (= Anchistioides gardineri) and Amphipalaemon cooperi Borradaile, 1915 (= Anchistioides cooperi) which were later synonomyzed with Anchisitioides willeyi by Gordon (1935), who also suggested their conspecificity with Anchistioides australiensis. At the present time, Anchistioides australiensis is a valid species (Bruce, 1971; Chace & Bruce, 1993) based on specific morphological features such as the presence of sharp postorbital tooth, oblique distal lamela of scaphocerite and sharply produced spines on posterodorsal angles of sixth abdominal somite (see Bruce, 1971: fig. 9). The other Indo-Pacific species, Anchistioides compressus and A. willeyi, can be clearly identified by specific form of scaphocerite, the presence of a well marked blunt postorbital tubercle in A. willeyi which is absent in A. compressus (e.g., Bruce, 1971) and the number of ventral rostral teeth (3-4 large ventral rostral teeth present in A. willeyi while up to 8 small ventral rostral teeth in A. compressus (Paulson, 1875; Gordon, 1935)). Anchistioides antiguensis is clearly separated geographically being known only from the tropical Western Atlantic and Caribbean region (Schmitt, 1924; Holthuis, 1951; Wheeler & Brown, 1968; Martinez-Iglesias, 1986; Markham et al, 1990; Ramos-Porto et al, 1998; Cardoso, 2006).

Redescription of Butlerius butleri Goodey, 1929 (Nematoda: Diplogastridae) from South Korea

Nematology ◽  
2009 ◽  
Vol 11 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Il-Kweon Yeon ◽  
Gaurav Singh ◽  
Irfan Ahmad ◽  
Chung-Don Choi
Keyword(s):  
South Korea ◽  
Reproductive System ◽  
Type Species ◽  
The Other ◽  
Korean Population ◽  
Female Reproductive System ◽  
Caudal Region ◽  
Additional Information ◽  
Type Population

AbstractThe type species of the genus Butlerius, viz., B. butleri Goodey, 1929, is redescribed and illustrated from specimens collected in South Korea. Additional information is provided for the cuticle, stoma structure, female reproductive system and the male caudal region. The Korean population is 1336-1857 μm long, a = 33.9-43.5, b = 5.41-6.34, c = 3.38-4.20, c′ = 14.13-19.0 and V = 40-45%. Males have spicules 39-49 μm long and a gubernaculum 25-33 μm long. There are nine pairs of genital papillae, three pairs precloacal and six pairs postcloacal. The v5,6,7 clusters are widely separated, one group situated just posterior to the phasmids and the other group at level of pd. Although there are some differences in morphometrics as compared with the type population, the species is easily identified by the similarities in the structure of the stoma, pharynx, spicules and gubernaculum. Butlerius singularis and B. filicaudatus are proposed as synonyms of the type species.

Rediagnosis of the squat lobster genus Gastroptychus Caullery, 1896, with a new genus Sternostylus and a new family Sternostylidae (Crustacea: Decapoda: Anomura: Chirostyloidea)

Zootaxa ◽  
2018 ◽  
Vol 4524 (1) ◽  
pp. 77 ◽  
Author(s):  
KEIJI BABA ◽  
SHANE T. AHYONG ◽  
KAREEN E. SCHNABEL
Keyword(s):  
Type Species ◽  
Anterior Margin ◽  
New Genus ◽  
Sister Group ◽  
Sensu Stricto ◽  
The Other ◽  
Squat Lobster ◽  
Terminal Spine ◽  
New Family ◽  
Left And Right

The chirostyloidean squat lobster genus Gastroptychus Caullery, 1896 is revised and is split into two genera: Gastroptychus sensu stricto (type species, Ptychogaster spinifer A. Milne-Edwards, 1880) and Sternostylus new genus (type species, Ptychogaster formosus Filhol, 1884). Gastroptychus sensu stricto, is restricted to nine species with a sternal plastron, at sternite 3, abruptly demarcated from the preceding sternites (excavated sternum) by a distinct step forming a well-defined transverse or concave anterior margin at the articulation with maxillipeds 3, the maxillipeds 3 widely separated, with the distal parts accommodated in the excavated sternum between the left and right maxillipeds 3 when folded, and the P2–4 dactyli with the terminal spine demarcated by a suture. Sternostylus new genus, represented by 12 species, has the sternite 3 anteriorly bluntly produced medially and steeply sloping anterodorsally to the anterior sternite, with a pair of spines directly behind the anterior margin, the left and right maxillipeds 3 adjacent, and the P2–4 dactyli ending in an indistinctly demarcated corneous spine. The above-mentioned characters of Gastroptychus are consistent with Chirostylidae sensu stricto. Published molecular phylogenies indicate, however, that Sternostylus is the sister group to all the other Chirostylidae, and is designated the type genus of a new family, Sternostylidae. 

scholarly journals Spiribacter aquaticus Leon et al. 2017 is a later heterotypic synonym of Spiribacter roseus Leon et al. 2016. Reclassification of Halopeptonella vilamensis Menes et al. 2016 as Spiribacter vilamensis comb. nov.

2020 ◽  
Vol 70 (4) ◽  
pp. 2873-2878 ◽  
Author(s):  
María José León ◽  
Cristina Galisteo ◽  
Antonio Ventosa ◽  
Cristina Sánchez-Porro
Keyword(s):  
Type Species ◽  
Single Species ◽  
Amino Acid Identity ◽  
The Other ◽  
Phylogenomic Analysis ◽  
Content Type ◽  
Link Type ◽  
Average Amino Acid Identity ◽  
Single Genus ◽  
Type Strains

A comparative taxonomic study of Spiribacter and Halopeptonella species was carried out using a phylogenomic approach based on comparison of the core genome, orthologous average nucleotide identity (OrthoANIu), Genome-to-Genome Distance Calculator (GGDC) and average amino acid identity (AAI). Phylogenomic analysis based on 976 core translated gene sequences obtained from their genomes showed that Spiribacter aquaticus SP30T, S. curvatus UAH-SP71T, S. roseus SSL50T, S. salinus M19-40T and Halopeptonella vilamensis DSM 21056T formed a robust cluster, clearly separated from the remaining species of closely related taxa. AAI between H. vilamensis DSM 21056T and the species of the genus Spiribacter was ≥73.1 %, confirming that all these species belong to the same single genus. On the other hand, S. roseus SSL50T and S. aquaticus SP30T showed percentages of OrthoANIu and digital DNA–DNA hybridization of 98.4 % and 85.3 %, respectively, while these values among those strains and the type strains of the other species of Spiribacter and H. vilamensis DSM 21056T were ≤80.8 and 67.8 %, respectively. Overall, these data show that S. roseus SSL50T and S. aquaticus SP30T constitute a single species and thus that S. aquaticus SP30T should be considered as a later, heterotypic synonym of S. roseus SSL50T based on the rules for priority of names. We propose an emended description of S. roseus , including the features of S. aquaticus . We also propose the reclassification of H. vilamensis as Spiribacter vilamensis comb. nov.

Instability Study of Repetitive Nanosecond Pulsed Discharge Plasma in a Plasma Assisted Burner

2020 ◽  
Author(s):  
Saeid Zare ◽  
Omid Askari
Keyword(s):  
High Velocity ◽  
Discharge Plasma ◽  
Diffusion Flames ◽  
High Energy ◽  
Discharge Voltage ◽  
Low Energy ◽  
Peak Discharge ◽  
The Other ◽  
Other Hand ◽  
Point To Point

Abstract High velocity flows, as in aerospace applications require special techniques to stabilize and ignite diffusion flames. Some techniques focus on changing parameters like geometry, conditions of the flow, or fuel composition, but these techniques are usually too expensive or impossible due to major changes in the system. On the other hand, some techniques focus on generating a region of charged/excited species and active radicals upstream of the flame. That can substantially enhance the flame stability even under high strain rate or at lean-limit-flammability conditions. Repetitive nanosecond pulsed (RNP) discharge plasma is a nonthermal plasma technique with some remarkable potential to improve stability and ignitability of high velocity diffusion flames. This technique was used in previous papers in a plasma assisted coaxial inverse diffusion burner and showed some promising results by reducing the lift-off height and delaying detachment and blowout conditions. This burner is prepared to employ the discharges at the burner nozzle and simulate a single element of a multi-element methane burner. However, effectiveness of high-voltage high-frequency RNP plasma was limited by the mode of the discharge. During the tests, three different modes were observed at different combinations of plasma and flow conditions. These three modes are low energy corona, uniformly distributed plasma, and high-energy point-to-point discharge. Among these three, only well-distributed plasma significantly improved the flame. In other cases, plasma deployment was either ineffective or in some cases adversely affected the flame by producing undesirable turbulence advancing blow out. As a result, a comprehensive study of these modes is required. In this work, the transition between these three modes in a jet flame was discussed. It has been expressed as a function of plasma conditions, i.e. peak discharge voltage and discharge frequency. It was shown that increasing flow speed delays increases the voltage and frequency at which transition occurs from low-energy corona discharge to well distributed plasma discharge. Subsequently, the effective plasma conditions are thinned. On the other hand, by increasing the frequency of nanosecond discharges, the chance of unstable point-to-point discharges is decreased. In contrast, the discharge peak voltage causes two different consequences. If it is too low, the pulse intensity is too week that the system will experience no visible plasma discharges or the discharges will not pass the low-energy corona, no matter how high the frequency is. If too high, it will enhance the chance of point-to-point discharges and limits the stabilization outcome of the system. Therefore, an optimal region is found for peak discharge voltage.

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