scholarly journals The diverse radiodont fauna from the Marjum Formation of Utah, USA (Cambrian: Drumian)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10509
Author(s):  
Stephen Pates ◽  
Rudy Lerosey-Aubril ◽  
Allison C. Daley ◽  
Carlo Kier ◽  
Enrico Bonino ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
Relative Proportion ◽  
The Other ◽  
Supporting Evidence ◽  
New Taxon ◽  
Taxonomic Assignment ◽  
Variable Size ◽  
Free Swimming ◽  
Oral Cone

Radiodonts have long been known from Cambrian deposits preserving non-biomineralizing organisms. In Utah, the presence of these panarthropods in the Spence and Wheeler (House Range and Drum Mountains) biotas is now well-documented. Conversely, radiodont occurrences in the Marjum Formation have remained scarce. Despite the large amount of work undertaken on its diverse fauna, only one radiodont (Peytoia) has been reported from the Marjum Biota. In this contribution we quadruple the known radiodont diversity of the Marjum fauna, with the description of the youngest members of two genera, Caryosyntrips and Pahvantia, and that of a new taxon Buccaspinea cooperi gen. et sp. nov. This new taxon can be identified from its large oral cone bearing robust hooked teeth with one, two, or three cusps, and by the unique endite morphology and organisation of its frontal appendages. Appendages of at least 12 podomeres bear six recurved plate-like endites proximal to up to four spiniform distal endites. Pahvantia hastata specimens from the Marjum Formation are particularly large, but otherwise morphologically indistinguishable from the carapace elements of this species found in the Wheeler Formation. One of the two new Caryosyntrips specimens can be confidently assigned to C. camurus. The other bears the largest spines relative to appendage length recorded for this genus, and possesses endites of variable size and unequal spacing, making its taxonomic assignment uncertain. Caryosyntrips, Pahvantia, and Peytoia are all known from the underlying Wheeler Formation, whereas isolated appendages from the Spence Shale and the Wheeler Formation, previously assigned to Hurdia, are tentatively reidentified as Buccaspinea. Notably, none of these four genera occurs in the overlying Weeks Formation, providing supporting evidence of a faunal restructuring around the Drumian-Guzhangian boundary. The description of three additional nektonic taxa from the Marjum Formation further documents the higher relative proportion of free-swimming species in this biota compared to those of the Wheeler and Weeks Lagerstätten. This could be related to a moderate deepening of the basin and/or changing regional ocean circulation at this time.

RHYNCHOLITES AND THE PROBLEM OF NARROW AND BROAD CONCEPTION OF TAXONS

2018 ◽  
pp. 12-17 ◽  
Author(s):  
I. R. Khuzina ◽  
V. N. Komarov
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Characteristics ◽  
Mass Scale ◽  
Individual Variability ◽  
Point Of View ◽  
The Other ◽  
New Taxon ◽  
Artificial System ◽  
Broad Understanding

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.

A giant within Carpocorini (Hemiptera: Heteroptera: Pentatomidae): Description of Adustonotus graziae sp. nov.

Zootaxa ◽  
2021 ◽  
Vol 4958 (1) ◽  
pp. 489-502
Author(s):  
FILIPE MICHELS BIANCHI
Keyword(s):  
Morphological Characters ◽  
The Other ◽  
Total Evidence ◽  
Valid Species ◽  
Phylogenetic Position ◽  
New Taxon ◽  
Large Size ◽  
Internal Genitalia ◽  
Evidence Analysis ◽  
Heteroptera Pentatomidae

The Carpocorini are distributed worldwide, and it is one of the most speciose tribes within the Pentatomidae with 127 genera and more than 500 valid species. Recently, Adustonotus Bianchi was described to contain eight species formerly placed within Euschistus Dallas. Among them, Adustonotus grandis (Rolston) and Adustonotus latus (Dallas) are remarkable for their large size. Herein, the phylogenetic position of a new taxon is inferred by a total evidence analysis based on 85 morphological characters and four molecular markers. Adustonotus graziae sp. nov. is described, and is recovered in a polytomic lineage, including A. grandis and A. latus. These species share a solid combination of features that enable them to be separated from the other Adustonotus species (e.g., large size, the humeral angles spatulate and exceptionally produced, and the capsula seminalis shortened). Illustrations of external and internal genitalia, and a distributional map are provided. 

Taxonomic review of Epicadinus Simon, 1895 (Araneae: Thomisidae) 

Zootaxa ◽  
2018 ◽  
Vol 4459 (2) ◽  
pp. 201 ◽  
Author(s):  
ANDRÉ WANDERLEY DO PRADO ◽  
RENNER LUIZ CERQUEIRA BAPTISTA ◽  
MIGUEL MACHADO
Keyword(s):  
French Guiana ◽  
The Other ◽  
Valid Species ◽  
Variable Size ◽  
Size And Shape ◽  
Taxonomic Review ◽  
Nomen Dubium ◽  
The World ◽  
Senior Synonym

The genus Epicadinus Simon, 1895 can easily be distinguished from the other Neotropical Stephanopines by their abundant and robust setiferous tubercles, topped by elongated macrosetae, which cover most of the tegument. Additionally, the genus can be recognized by a pair of conical ocular mounds above the ALE, the anterior eye row very recurved, posterior one slightly procurved; carapace flattened and without tubercles, and opisthosoma with three conical projections (“tubercles”) of variable size and shape. This work is a taxonomic review of the 12 valid species of Epicadinus as listed in version 19 of the World Spider Catalogue (2018), whose hitherto known distribution included few records from Brazil, French Guiana, Bolivia and Peru, and only one from Mexico. Four valid species are recognized: Epicadinus biocellatus Mello-Leitão, 1929; E. trispinosus (Taczanowski, 1872) [with two junior synonyms E. trifidus (Pickard-Cambridge, 1893) syn. nov. and E. cornutus (Taczanowski, 1872) syn. nov.]; E. spinipes (Blackwall, 1862) [with two junior synonyms E. albimaculatus Mello-Leitão, 1929 syn. nov. and E. gavensis Soares, 1946 syn. nov]; and E. villosus [with two junior synonyms E. helenae Piza, 1936 syn. nov. and E. marmoratus Mello-Leitão, 1947 syn. nov.]. Epicadinus polyophthalmus Mello-Leitão, 1929 and Epicadinus tuberculatus Petrunkevitch, 1910 are transferred to Epicadus. Epicadus polyophthalmus (Mello-Leitão, 1929) comb. nov. is considered a nomen dubium. Epicadus tuberculatus (Petrunkevitch, 1910) comb. nov. is a senior synonym of Epicadus pustulosus (Mello-Leitão, 1929) syn. nov. 

scholarly journals A numerical study of the response of tropical Pacific SST to atmospheric forcing

MAUSAM ◽  
2021 ◽  
Vol 48 (4) ◽  
pp. 657-668
Author(s):  
XIAOMING LIU ◽  
JOHN M. MORRISON ◽  
LIAN XIE
Keyword(s):  
Ocean Circulation ◽  
Numerical Study ◽  
Ocean Model ◽  
Tropical Pacific ◽  
The Other ◽  
Atmospheric Forcing ◽  
Transfer Coefficients ◽  
Low Wind Speed ◽  
Sensitivity Tests ◽  
The Tropical Pacific

Two sets of atmospheric forcing from NCEP/NCAR 40-year reanalysis project, one based on monthly averaged climatological data and the other on 1982-83 monthly averaged data, are used to derive the global Miami Isopycnic Coordinate Ocean Model (MICOM). These two runs are referred to as the climatological experiments and 1982-83 El Nino experiments. Sensitivity tests of tropical Pacific SST to different bulk parameterizations of air-sea heat and momentum fluxes are carried out in the two experiments. Primary results show that constant transfer coefficients                          (1.2 × 10-3) for heat flux greatly overestimate the tropical Pacific SST, whereas the Liu-Katsaros-Businger (Liu et al. 1979) method can significantly improve the SST simulation especially under very low-wind speed conditions. On the other hand, Large and Pond (1982) formulation of the drag coefficient made little difference on the tropical Pacific SST simulation although it might modify the surface ocean circulation. The SST seasonal cycle and interannual variability of tropical Pacific SST are also examined in this study. Since SST is the most important oceanic parameter that provides the link between the atmosphere and the ocean, this evaluation of different parameterization schemes may facilitate future studies on coupling ocean-atmospheric numeric models.    

scholarly journals Accuracy Analysis of Gravity Field Changes from Grace RL06 and RL05 Data Compared to in Situ Gravimetric Measurements in the Context of Choosing Optimal Filtering Type

2020 ◽  
Vol 55 (3) ◽  
pp. 100-117
Author(s):  
Viktor Szabó ◽  
Dorota Marjańska
Keyword(s):  
Gravity Field ◽  
Ocean Circulation ◽  
Gravity Data ◽  
The Other ◽  
Subsurface Water ◽  
Satellite Gravity ◽  
Absolute Gravimetry ◽  
The Earth ◽  
Gravity Measurements ◽  
Gravity Recovery

AbstractGlobal satellite gravity measurements provide unique information regarding gravity field distribution and its variability on the Earth. The main cause of gravity changes is the mass transportation within the Earth, appearing as, e.g. dynamic fluctuations in hydrology, glaciology, oceanology, meteorology and the lithosphere. This phenomenon has become more comprehensible thanks to the dedicated gravimetric missions such as Gravity Recovery and Climate Experiment (GRACE), Challenging Minisatellite Payload (CHAMP) and Gravity Field and Steady-State Ocean Circulation Explorer (GOCE). From among these missions, GRACE seems to be the most dominating source of gravity data, sharing a unique set of observations from over 15 years. The results of this experiment are often of interest to geodesists and geophysicists due to its high compatibility with the other methods of gravity measurements, especially absolute gravimetry. Direct validation of gravity field solutions is crucial as it can provide conclusions concerning forecasts of subsurface water changes. The aim of this work is to present the issue of selection of filtration parameters for monthly gravity field solutions in RL06 and RL05 releases and then to compare them to a time series of absolute gravimetric data conducted in quasi-monthly measurements in Astro-Geodetic Observatory in Józefosław (Poland). The other purpose of this study is to estimate the accuracy of GRACE temporal solutions in comparison with absolute terrestrial gravimetry data and making an attempt to indicate the significance of differences between solutions using various types of filtration (DDK, Gaussian) from selected research centres.

scholarly journals Goldilocks mixing in oceanic shear-induced turbulent overturns

2021 ◽  
Vol 928 ◽  
Author(s):  
A. Mashayek ◽  
C.P. Caulfield ◽  
M.H. Alford
Keyword(s):  
Ocean Circulation ◽  
Turbulent Mixing ◽  
Intermediate Phase ◽  
Turbulent Flux ◽  
Geographical Location ◽  
Small Scale ◽  
Supporting Evidence ◽  
Stratified Turbulence ◽  
Wide Range ◽  
Variable Flux

We present a new, simple and physically motivated parameterization, based on the ratio of Thorpe and Ozmidov scales, for the irreversible turbulent flux coefficient $\varGamma _{\mathcal {M}}= {\mathcal {M}}/\epsilon$ , i.e. the ratio of the irreversible rate ${\mathcal {M}}$ at which the background potential energy increases in a stratified flow due to macroscopic motions to the dissipation rate of turbulent kinetic energy $\epsilon$ . Our parameterization covers all three key phases (crucially, in time) of a shear-induced stratified turbulence life cycle: the initial, ‘hot’ growing phase, the intermediate energetically forced phase and the final ‘cold’ fossilization decaying phase. Covering all three phases allows us to highlight the importance of the intermediate one, to which we refer as the ‘Goldilocks’ phase due to its apparently optimal (and so neither too hot nor too cold, but just right) balance, in which energy transfer from background shear to the turbulent mixing is most efficient. The value of $\varGamma _{\mathcal {M}}$ is close to 1/3 during this phase, which we demonstrate appears to be related to an adjustment towards a critical or marginal Richardson number for sustained turbulence ${\sim }0.2\text {--}0.25$ . Importantly, although buoyancy effects are still significant at leading order for the turbulent dynamics during this intermediate phase, the marginal balance in the flow ensures that the turbulent mixing of the (density) scalar is nevertheless effectively ‘locked’ to the turbulent mixing of momentum. We present supporting evidence for our parameterization through comparison with six oceanographic datasets that span various turbulence generation regimes and a wide range of geographical location and depth. Using these observations, we highlight the significance of parameterizing an inherently variable flux coefficient for capturing the turbulent flux associated with rare energetic, yet fundamentally shear-driven (and so not strongly stratified) overturns that make a disproportionate contribution to the total mixing. We also highlight the importance of representation of young turbulent patches in the parameterization for connecting the small scale physics to larger scale applications of mixing such as ocean circulation and tracer budgets. Shear-induced turbulence is therefore central to irreversible mixing in the world's oceans, apparently even close to the seafloor, and it is critically important to appreciate the inherent time dependence and evolution of mixing events: history matters to mixing.

scholarly journals New or previously unrecorded avian taxa from the Middle Eocene of Messel (Hessen, Germany)

Fossil Record ◽  
2000 ◽  
Vol 3 (1) ◽  
pp. 207-219 ◽  
Author(s):  
G. Mayr
Keyword(s):  
Middle Eocene ◽  
The Other ◽  
New Taxon ◽  
New Information ◽  
Wenn Sich

Three new or from this site previously unrecorded birds are described from the Middle Eocene of Messel (Hessen, Germany). <i>Serudaptus pohli</i> n. gen. n. sp. is a new taxon of the Pseudasturidae and is distinguished from the other species of this family by its short and stout tarsometatarsus and the long and strong claws. An isolated foot of a gruiform bird is assigned to <i>Idiornis</i> cf. <i>itardiensis</i> (Idiornithidae) and would, if this assignment can be confirmed, demonstrate the existence of this species for a period of 23 million years. The proportions of the toes suggest that <i>Idiornis</i> cf. <i>itardiensis</i> was less cursorial than its next recent relatives, the Cariamidae. In addition thereto, an exceptionally well preserved skeleton of a sandcoleid bird (Coliiformes: Sandcoleidae) gives new information on the osteology and feathering of sandcoleid birds. The specimen resembles the genera <i>Eoglaucidium</i> and <i>Anneavis</i> but it has not been possible to assign it to one of these two genera with certainty. <br><br> Drei neue oder von dieser Fundstelle bisher nicht nachgewiesene Vögel werden aus dem Mittel-Eozän von Messel (Hessen, Deutschland) beschrieben. <i>Serudaptus pohli</i> n. gen. n. sp. ist ein neues Taxon der Pseudasturidae und unterscheidet sich von den anderen Arten dieser Familie durch den kurzen und gedrungenen Tarsometatarsus und die langen, kräftigen Krallen. Der isolierte Fuß eines gruiformen Vogels wird <i>Idiornis</i> cf. <i>itardiensis</i> (Idiornithidae) zugeordnet und würde, wenn sich diese Zuordnung bestätigt, die Existenz dieser Art über einen Zeitraum von 23 Millionen Jahren zeigen. Die Zehenproportionen legen nahe, dass <i>Idiornis</i> cf. <i>itardiensis</i> weniger an eine laufende Lebensweise angepasst war als seine nächsten rezenten Verwandten, die Cariamidae. Darüber hinaus zeigt ein außergewöhnlich gut erhaltenes Skelett eines Vertreters der Sandcoleidae bisher unbekannte Einzelheiten der Osteologie und Befiederung dieser Familie. Das Exemplar ähnelt den Gattungen <i>Eoglaucidium</i> und <i>Anneavis</i>, konnte jedoch keiner der beiden Gattungen mit Sicherheit zugeordnet werden. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20000030110" target="_blank">10.1002/mmng.20000030110</a>

An Account of Larval Budding in the Compound Ascidian, Hypsistozoa fasmeriana

1959 ◽  
Vol s3-100 (52) ◽  
pp. 575-589
Author(s):  
BERYL I. BREWIN
Keyword(s):  
Neural Tube ◽  
Ventral Side ◽  
The Other ◽  
Free Swimming ◽  
Close Link ◽  
Bud Formation ◽  
Maximal Size ◽  
The Right ◽  
Sexually Mature ◽  
Posterior Position

Larval budding in Hypsistozoa fasmeriana is in many ways unique in the sub-family Holozoinae. The stolon, which projects from the left side of the oozooid, is large (235 µ in diameter, 1.8 mm in length) and reaches maximal size before severance of buds occurs. The buds arise one at a time and 9 to 14 are formed. Test forms rapidly between a newly severed bud and the remainder of the stolon. Thus the buds are moved along an arc of a spiral which runs from the left side of the oozooid somewhat anteriorly across the ventral side and posteriorly up the right side. By the end of bud formation the first-formed bud occupies the most posterior position, lying high up on the right side of the oozooid. Each larval bud develops directly into a blastozooid and by the time the tadpole becomes free-swimming there is a considerable degree of organogenesis. The blastozooids together with the oozooid form a ring of zooids tilted slightly away from the vertical. After metamorphosis of the tadpole this ring becomes horizontal, but the tilt is still maintained with the oozooid occupying the most elevated position. Thus in the young colonies the plane of the head is slightly off the horizontal--an arrangement which persists throughout the life of the colony. The development of larval buds in this ascidian is not delayed until after dedifferentiation of the oozooid, as is the case in the other Holozoinae. The blastozooids function simultaneously with the oozooid. They do not, however, become sexually mature, being presumably of sub-maximal size for the species. The newly severed bud differs from that of other Holozoinae in having an extensive epicardial tube and a thick mesenchymal layer of densely granulated cells. The epicardium of the blastozooid is formed from the posterior end of the original epicardial tube. It remains single. The neural tube arises from the left peribranchial sac. H. fasmeriana forms a close link between the sub-family Holozoinae and the sub-family Polyclininae. It resembles the Holozoinae in form of gut, position and mode of origin of the brood pouch, and position of the cardio-pericardium. It shares with the Polyclininae the post-abdominal position of the gonads as well as the structure and organogenesis of the buds.

Cloud-Seeding Analysis in Oregon *

1953 ◽  
Vol 34 (7) ◽  
pp. 298-303 ◽  
Author(s):  
R. T. Beaumont
Keyword(s):  
Regression Method ◽  
The Other ◽  
Supporting Evidence ◽  
Cloud Seeding ◽  
Other Hand ◽  
Oregon Cascades

Two separate evaluations of commercial cloud-seeding operations in Oregon are discussed using the regression method with non-seeded control areas. No supporting evidence that cloud-seeding materially increased precipitation is found. On the other hand, strongest evidence found in these analyses of possible precipitation modification which could be attributed to cloud-seeding is a decrease of snowfall for two winters in the Southern Oregon Cascades.

Variability in the Proportion and Type of Subunits in Lupin Storage Globulins

1975 ◽  
Vol 2 (1) ◽  
pp. 29 ◽  
Author(s):  
JM Gillespie ◽  
RJ Blagrove
Keyword(s):  
Protein Structure ◽  
Electrophoretic Mobility ◽  
Relative Proportion ◽  
Genetic Selection ◽  
Molecular Size ◽  
The Other ◽  
Subunit Composition ◽  
Molecular Weights ◽  
Species Specific ◽  
Conglutin Γ

The seeds of 12 species of lupin were examined and were found to contain two major globulins, conglutins α and β, while some contained a third minor globulin, conglutin �. There were considerable differences between species in the electrophoretic mobility and proportions of conglutins α and β, and in their subunit composition in terms of the number of components, their molecular weights and the importance of disulphide bonding between them. However, the electrophoretic behaviour and subunit composition of conglutins α and β did appear to be species-specific. Conglutin γ, on the other hand, did not seem to vary in molecular size or electrophoretic mobility within this genus. The 18 cultivars of Lupinus angustifolius examined appeared to be more closely related in terms of the number and size of subunits, although variations were apparent in the relative proportion of these subunits, especially with wild types. It is suggested that this variability in the protein structure of lupin globulins may provide evidence that substantial changes can be induced by genetic selection in the composition of these proteins without upsetting their structure-function relations.

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