Marginal dentition and multiple dermal jawbones as the ancestral condition of jawed vertebrates

Science ◽  
2020 ◽  
Vol 369 (6500) ◽  
pp. 211-216 ◽  
Author(s):  
Valéria Vaškaninová ◽  
Donglei Chen ◽  
Paul Tafforeau ◽  
Zerina Johanson ◽  
Boris Ekrt ◽  
...  
Keyword(s):  
Tooth Replacement ◽  
The Czech Republic ◽  
Early Devonian ◽  
Ancestral Condition ◽  
Bony Fishes ◽  
The Common ◽  
Cartilaginous Fishes ◽  
Dermal Bones ◽  
Synchrotron Microtomography ◽  
Land Vertebrates

The dentitions of extant fishes and land vertebrates vary in both pattern and type of tooth replacement. It has been argued that the common ancestral condition likely resembles the nonmarginal, radially arranged tooth files of arthrodires, an early group of armoured fishes. We used synchrotron microtomography to describe the fossil dentitions of so-called acanthothoracids, the most phylogenetically basal jawed vertebrates with teeth, belonging to the genera Radotina, Kosoraspis, and Tlamaspis (from the Early Devonian of the Czech Republic). Their dentitions differ fundamentally from those of arthrodires; they are marginal, carried by a cheekbone or a series of short dermal bones along the jaw edges, and teeth are added lingually as is the case in many chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods). We propose these characteristics as ancestral for all jawed vertebrates.

scholarly journals The contemporary cartographic presentation of geographical names of objects lying on the border between Poland and the Czech Republic

2015 ◽  
Vol 47 (3) ◽  
pp. 159-174
Author(s):  
Maciej Zych
Keyword(s):  
Czech Republic ◽  
Topographic Maps ◽  
National Register ◽  
The Czech Republic ◽  
Common Boundary ◽  
Mountain Ranges ◽  
Single Region ◽  
The Common ◽  
Mountain Basins ◽  
Own Name

Abstract The aim of this paper is the analysis of the names used on cartographic publications in Poland and the Czech Republic for transboundary geographical objects lying on the common boundary. After the analysis of the Czech and Polish topographic maps that are available on the national geoportals, maps of the divisions into natural regions, and toponymic databases (Polish the National Register of Geographical Names, and Czech Geonames – the Database of geographic names of the Czech Republic) it was established that 360 named geographic objects lie on this boundary. This number includes: 123 hydronyms (names of rivers and other streams), 224 oronyms (139 names of summits, 22 names of mountain passes, 35 names of mountain ranges and ridges, 15 names of highlands, plateaus and uplands, 7 names of mountain basins, valleys and depressions, 3 names of lowlands, and 3 names of rocks), 9 names of forests, 1 name of mountain meadow (alp), and 3 names of tracks. 212 of these objects (59%) have names in both languages – Polish and Czech, however, in 99 cases (47% of objects that have name in both Polish and Czech languages) the Polish and Czech toponyms entirely do not correspond to each other. From the remaining objects 67 (18%) have only the Czech name, and 81 (23%) only the Polish name. In some natural regions, the limits of their ranges set by the Czech and Polish geographers vary widely, for example a single region on one side of the boundary corresponds to two or more regions on other side of the boundary. In other cases illustrations of incorrectness are more sophisticated, like the river that has different course according to the Czech or Polish maps (stream regarded as a main watercourse in one country, which has its own name, in another country is considered as a tributary one with a different name). In the summary, it should be stated that in the large part of the Polish and Czech names of the geographical objects lying on the common boundary were drawn regardless of the names used in the neighboring country.

scholarly journals Cartilaginous fishes (Class Chondrichthyes) from the Ichthyological Collection at the Federal University of Paraíba, Brazil

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Sarah TFL Viana ◽  
Danilo Lima ◽  
Katherine Viana ◽  
Antônio Felinto ◽  
Ricardo de Souza Rosa
Keyword(s):  
Fish Fauna ◽  
Public Consultation ◽  
Type Collection ◽  
Neotropical Fish ◽  
Full List ◽  
Bony Fishes ◽  
Fish Collection ◽  
Cartilaginous Fishes ◽  
Geographical Scope ◽  
Amazonian Region

Federal University of Paraíba (UFPB) ichthyological collection comprises over 11,000 lots of species of cartilaginous and bony fishes from marine, estuarine and freshwater realms. Due to the collection size, rarity of some specimens, taxonomic and geographical scope, this collection represents a substantial archive of the Neotropical fish fauna, especially concerning the Northeast Brazilian region. Currently, UFPB fish collection is under bioinformatization and curatorial transitions. Hence, the present study aimed to provide a detailed analysis of the Chondrichthyan collection database in which the systematic, spatial and chronological coverages are discussed. Full list of collection objects, updated nomenclature and type collection extent are given for public consultation. There are 504 lots of sharks, batoids and chimaeras that are classified within 10 orders, 22 families, 34 genera, and 64 species. Myliobatiformes and Carcharhiniformes represent taxa with higher number of lots in which freshwater stingrays (Potamotrygonidae) and requiem sharks (Carcharhinidae) stand out. Specimens were mostly collected in the marine coastline off Paraíba state and lower Amazonian region, which set UFPB fish collection as an outstanding scientific collection of the regional genetic heritage. 

Role of three bird species in the life cycle of two Sarcocystis species (Apicomplexa, Sarcocystidae) in the Czech Republic

2021 ◽  
Author(s):  
Ondřej Máca ◽  
David González
Keyword(s):  
Czech Republic ◽  
Intestinal Mucosa ◽  
Bird Species ◽  
Great Cormorant ◽  
Sarcocystis Species ◽  
The Czech Republic ◽  
Leg Muscles ◽  
The Common ◽  
Milvus Milvus

Abstract BackgroundBirds are one of the groups involved in the development of Sarcocystis Lankester, 1882, serving either as intermediate or definitive hosts. The white-tailed sea eagle Haliaeetus albicilla (Linnaeus, 1758), red kite Milvus milvus (Linnaeus, 1758) (both Accipitriformes) and common starlings Sturnus vulgaris Linnaeus, 1758 (Passeriformes) were examined to elucidate their participation in the development of Sarcocystis, as well as to determine the specific identity of the parasites based on morphological and especially molecular analyses.MethodsIn 2020–2021, one white-tailed eagle, one red kite and five common starlings were parasitologically examined for the presence of Sarcocystis using flotation centrifugation coprological method and by wet mounts of intestinal mucosa scrapings and/or muscle samples. Positive samples were processed by light microscopy, histologically and followed molecularly at four genetic markers (18S rRNA, 28S rRNA, ITS1 and cox1).ResultsThe white-tailed eagle harboured oocysts/sporocysts of S. arctica Gjerde et Schulze, 2014 in the intestinal mucosa, while the intestinal mucosa of the red kite and breasts and leg muscles of one common starling were positive to S. halieti Gjerde, Vikøren et Hamnes, 2018. Sequences from eagle shared 99.6 − 100% identity with each other and S. arctica in the red fox (V. vulpes Linnaeus, 1758) from the Czech Republic. Sequences from the common starling and red kite shared 100% identity with each other and with S. halieti in the great cormorant (P. carbo [Linnaeus, 1758]) from Lithuania and H. albicilla from Norway.ConclusionsThe white-tailed sea eagle (H. albicilla) acts as natural definitive host of S. arctica, whereas the common starling (St. vulgaris) and red kite (M. milvus) represent intermediate and definitive hosts, respectively, for S. halieti.

scholarly journals Comparison of agricultural subsidies in the Czech Republic and in the selected states of the European Union

2009 ◽  
Vol 55 (No. 11) ◽  
pp. 519-533 ◽  
Author(s):  
F. Střeleček ◽  
R. Zdeněk ◽  
J. Lososová
Keyword(s):  
Czech Republic ◽  
Life Quality ◽  
The European Union ◽  
Agricultural Subsidies ◽  
The Czech Republic ◽  
Subsidy Rate ◽  
European Heritage ◽  
The Common ◽  
The Difference ◽  
The Eu

The Common Agricultural Policy has been implemented in order to guarantee the appropriate life quality for farmers and to preserve the European heritage. Costs of its realization amounted to 40% of the EU budget. The EU has not established the same conditions for all member states. The aim of the paper is to assess the influence of agricultural subsidies and the structure of production on the incomes of agricultural holdings and their comparison with the largest producers in the EU with similar production structure. The shift-share analysis is used. Different amount of subsidies according to the type of farming together with increasing subsidy rate may influence the type of farming. Therefore, it may cause a paradox that the structure of subsidies according to the type of farming will stimulate products that are currently suppressed. The difference in subsidies in comparison with the largest producers with a similar structure of agricultural production is significant for the Czech Republic and it is possible to compare it to the increase of the SAPS by 75%.

scholarly journals Statistical analysis of economic viability of farms operating in Czech areas facing natural constraints

2020 ◽  
Vol 66 (No. 5) ◽  
pp. 193-202
Author(s):  
Tomas Hlavsa ◽  
Jindrich Spicka ◽  
Marie Stolbova ◽  
Zuzana Hlouskova
Keyword(s):  
Agricultural Policy ◽  
Rural Areas ◽  
Value Added ◽  
Economic Viability ◽  
The Czech Republic ◽  
Field Crops ◽  
Farm Accountancy Data Network ◽  
The Common ◽  
Net Value Added ◽  
Grazing Livestock

The redesign of the Common Agricultural Policy (CAP) allows for more room to address issues related to stabilising farmers’ income and developing their viability in areas facing natural constraints (ANC). Maintaining income levels, developing farm economies in rural areas, and encouraging competitive agricultural practises are the challenges facing the new CAP. ANCs in the Czech Republic are characterised by a lower level of income compared to areas outside ANCs and their generally prevailing specialisation in livestock production, which has been facing a relatively turbulent development in the last decade. The main aim of this paper is to evaluate the economic viability with regard to the level of natural disadvantage and with regard to farm specialisation. The database of Farm Accountancy Data Network (FADN) was used for assessment; the authors built the Farm Economic Viability indicator, which is based on modified Farm Net Value Added. The differences between the farm groups were tested through analysis of variance. Significantly lower viability was found in ANCs compared to farms outside ANCs. Field crops achieved significantly higher levels, both in and outside ANCs. The most threatened group of farms are grazing livestock in ANCs.

scholarly journals X. On the male organs of some of the cartilaginous fishes

1839 ◽  
Vol 129 ◽  
pp. 139-149 ◽  
Keyword(s):  
The Common ◽  
Cartilaginous Fishes ◽  
Generative Organs

In a paper on the Torpedo, which was published in the Philosophical Transactions for 1834, I have briefly described the male generative organs of this fish as consisting of two firm oval testes, of vasa deferentia without vesiculae seminales, and of a papilla opening into the cloaca, the common termination of the seminal and urinary passages. Referring to Dr. Müller’s able work, “De glandularum secernentium structura penitiori,” in which he treats of the testes of the Rays and Sharks, I find that his de­scriptions and views of these organs are not in accordance with the above. His words are, “Maxime singularis est genitalium masculorum in Rajis et Squalis conformatio ; sunt enim organa glandulosa duplicis generis, altera, quae hucusque tanquam testiculi descripta sunt, ex globulis, non vero ex ductibus seminalibus conflata, altera, plerumque pro epididymidibus habita, ex canalibus serpentinis composita, sed minime cum testiculis globulosis conjuncta; quare non epididymides sed glandulas proprias esse conjicio.”

scholarly journals Analysis of distribution impact of subsidies within the Common Agricultural Policy on field production businesses in the Czech Republic

2012 ◽  
Vol 60 (7) ◽  
pp. 415-424 ◽  
Author(s):  
Gabriela Trnková ◽  
Z. Malá
Keyword(s):  
Czech Republic ◽  
Investment Activity ◽  
Equal Distribution ◽  
The Czech Republic ◽  
Economic Result ◽  
Management Quality ◽  
The Common ◽  
The Individual ◽  
The Impact ◽  
Field Production

The article deals with the analysis of inequality in the distribution of the economic result in businesses engaging in field production in the Czech Republic, by way of the assessment of the impact of subsidies on the said inequality and by defining the effect of the size of the business on the economic result as well as inequality. The methodical tool is the quantification of the Gini coefficient and its elasticity. The data basis consists of panel data of 140 agricultural businesses focusing on field production for the period of the years 2005–2010.The main results of the submitted article substantiate a high inequality in the distribution of the economic result for the accounting period among field production businesses. The said inequality is not generally caused by the differing size of the analyzed businesses, and the associated volume of subsidies obtained, but is affected by other factors, such as the management quality, the investment activity of the business, or exceptional events. Subsidies do contribute to the more equal distribution of the economic result, but their impact is very small. Out of the individual categories of subsidies, the ones with the main redistribution effect are direct payments, as a result of the high proportion of total subsidies that they comprise.

scholarly journals Možnosti zapojenia žiakov do praktickej ochrany prírody v rámci akcie „Pomoc ropuchám pri jarných migráciách“ na Železnej studienke v Bratislave (1986 – 2015)

Envigogika ◽  
2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Blanka Lehotská ◽  
Alena Magyarics
Keyword(s):  
Nature Conservation ◽  
School Children ◽  
Positive Impact ◽  
Bufo Bufo ◽  
The Czech Republic ◽  
The Common ◽  
Toad Bufo ◽  
Toad Bufo Bufo ◽  
Annual Mortality ◽  
Practical Nature

The paper presents one of the possibilities of the involvement of school children in practical nature conservation. It deals with the conservation issue of migrating amphibians. Based on 30 years of experience in protection of the common toad (Bufo bufo) population nin the Železná studienka locality in Bratislava, it specifies how to involve pupils in particular activities. At the same time it emphasizes the positive impact of school children participation in these activities on their knowledge level and attitude to nature conservation and environment protection. In Slovakia and the Czech Republic the number of sites is recorded where an annual mortality of protected animals is observed. This contribution is a guide and inspiration for teachers to show that pupils can work alongside them tocontribute to changing this situation.

scholarly journals Endochondral bone in an Early Devonian ‘placoderm’ from Mongolia

2020 ◽  
Author(s):  
Martin D. Brazeau ◽  
Sam Giles ◽  
Richard P. Dearden ◽  
Anna Jerve ◽  
Y.A. Ariunchimeg ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Sister Group ◽  
New Taxon ◽  
Endochondral Bone ◽  
Early Devonian ◽  
Skeletal Tissue ◽  
Bony Fishes ◽  
Computed Microtomography ◽  
Living Species ◽  
X Ray Computed

Endochondral bone is the main internal skeletal tissue of nearly all osteichthyans—the group comprising more than 60,000 living species of bony fishes and tetrapods. Chondrichthyans (sharks and their kin) are the living sister group of osteichthyans and have cartilaginous endoskeletons, long considered the ancestral condition for all jawed vertebrates (gnathostomes). The absence of bone in modern jawless fishes and the absence of endochondral ossification in early fossil gnathostomes appears to lend support to this conclusion. Here we report the discovery of extensive endochondral bone in Minjinia turgenensis, a new genus and species of ‘placoderm’-like fish from the Early Devonian (Pragian) of western Mongolia described using x-ray computed microtomography (XR-µCT). The fossil consists of a partial skull roof and braincase with anatomical details providing strong evidence of placement in the gnathostome stem group. However, its endochondral space is filled with an extensive network of fine trabeculae resembling the endochondral bone of osteichthyans. Phylogenetic analyses place this new taxon as a proximate sister group of the gnathostome crown. These results provide direct support for theories of generalised bone loss in chondrichthyans. Furthermore, they revive theories of a phylogenetically deeper origin of endochondral bone and its absence in chondrichthyans as a secondary condition.

scholarly journals Early Silurian (Llandovery) graptolites from central Saudi Arabia: First documented record of Telychian faunas from the Arabian Peninsula

GeoArabia ◽  
2007 ◽  
Vol 12 (4) ◽  
pp. 15-36 ◽  
Author(s):  
Zalasiewicz Jan ◽  
Williams Mark ◽  
Miller Merrell ◽  
Page Alex ◽  
Blackett Edward
Keyword(s):  
Saudi Arabia ◽  
Czech Republic ◽  
Arabian Peninsula ◽  
British Isles ◽  
Common Occurrence ◽  
The Czech Republic ◽  
Lower Silurian ◽  
Growth Increments ◽  
Low Diversity ◽  
The Common

ABSTRACT Graptolites from three shallow core holes penetrating lower Silurian strata in central Saudi Arabia identify rocks of mid Aeronian and early Telychian age. The graptolites comprise Campograptus undulatus?, C. lobiferus?, Lituigraptus convolutus, Metaclimacograptus bohemicus, Neolagarograptus rickardsi, Normalograptus? aff. scalaris, cf. Paradiversograptuscapillaris,Petalolithusminor,P.praecursor,P.ovatoelongatus?, Pristiograptus regularis sl, Pseudorthograptus insectiformis, Pseudoretiolites perlatus? and Torquigraptus? decipiens, which identify the mid Aeronian convolutus Biozone, and Monograptus bjerreskovae, Monograptus ex gr. marri, Paradiversograptus runcinatus?, Petalolithus cf. altissimus, Pristiograptus renaudi, Stimulograptus becki and S. halli?, which indicate the early Telychian guerichi Biozone. The graptolite faunas are generally of low diversity, with most levels yielding between one and three species, occasionally rising to as many as seven species. The palaeogeography of the depositional basin, coupled with the low diversity and the abundance of Pristiograptus and Normalograptus species, suggests a marine-shelf setting. This is also indicated by the common occurrence of benthic shelly fossils, including articulated bivalves and gastropods. In general, the graptolite faunas are of much lower diversity than contemporaneous marine assemblages from the British Isles or the Czech Republic, and probably represent a graptolite biotope of “cratonic invaders.” Graptolites are very well preserved, displaying detail of fusellar banding (growth increments) and perhaps ultrastructure.

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