scholarly journals A lowermost Ordovician tabulate-like coralomorph from the Precordillera of western Argentina: a main component of a reef-framework consortium

2016 ◽  
Vol 91 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Marcelo G. Carrera ◽  
Ricardo A. Astini ◽  
Fernando J. Gomez

AbstractAlthough putative corals of uncertain affinities occur in the early Cambrian, the earliest definite tabulate corals have not been described prior to the Early Ordovician in North America. This paper reports a new finding of a tabulate-like coralomorph forming part of biostratigraphically well-constrained reef mounds in the latest Cambrian–Early Ordovician La Silla Formation in the Argentine Precordillera. The oldest record of the coralomorph genus Amsassia is reported and a new species, A. argentina, is erected. The discovery of this genus in the lowermost Ordovician modifies the previously proposed paleogeographic distribution and patterns of origination and migration routes of this coral-like organism. Amsassia argentina n. sp. constitutes a main framework builder together with a complex microbial consortium. This oldest occurrence of Amsassia as a reef builder represents a new record of a skeletal organism in the gap of metazoan reef constructors after the demise of archaeocyaths in the late early Cambrian.

2019 ◽  
Vol 484 (1) ◽  
pp. 61-65
Author(s):  
R. M. Antonuk ◽  
A. A. Tretyakov ◽  
K. E. Degtyarev ◽  
A. B. Kotov

U–Pb geochronological study of amphibole-bearing quartz monzodiorites of the alkali-ultramafic Zhilandy complex in Central Kazakhstan, whose formation is deduced at the Early Ordovician era (479 ± 3 Ma). The obtained data indicate three stages of intra-plate magmatism in the western part of the Central Asian Orogenic Belt: Late Neoproterozoic stage of alkali syenites of the Karsakpay complex intrusion, Early Cambrian stage of ultramafic-gabbroid plutons of the Ulutau complex formation, and Late Cambrian–Early Ordovician stage of formation of the Zhilandy complex and Krasnomay complex intrusions.


The Auk ◽  
2021 ◽  
Author(s):  
Scott F Lovell ◽  
M Ross Lein ◽  
Sean M Rogers

Abstract Eastern (Vireo gilvus gilvus) and western (V. g. swainsoni) forms of the Warbling Vireo have essentially allopatric breeding ranges across north-central North America, but come into contact in central Alberta, Canada. In 1986, Jon Barlow presented preliminary morphological and song evidence suggesting that the Warbling Vireo complex might comprise more than one valid species. However, to date, Barlow’s suggestion is supported by only limited DNA evidence, demonstration of molt and migration differences between the taxa, and anecdotal accounts of differences in song, morphology, plumage, and ecology. We analyzed variation in both mitochondrial and nuclear DNA in birds from Alberta and surrounding areas to determine the levels of genetic differentiation and hybridization occurring in the contact zone, and whether the two taxa warrant recognition as separate biological species. Our analyses reveal that Warbling Vireos in Alberta and the surrounding areas are separated into two well-defined, genetically differentiated, and monophyletic clades corresponding to previously recognized taxonomic groups. The two taxa come into contact in a narrow (~85 km) zone in Barrhead County, northwest of Edmonton, Alberta. They show evidence of limited hybridization. The distinct genetic differences are maintained in the contact zone, where individuals of the two taxa may occupy neighboring territories. Differences in spring arrival dates, molt schedules, and migration routes indicate that a migratory divide may play an important role in reproductive isolation. We suggest that the two taxa are distinct cryptic species: an eastern form, Vireo gilvus, and a western form, Vireo swainsoni.


Taxonomy ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 60-68
Author(s):  
Jun Souma ◽  
Shûhei Yamamoto ◽  
Yui Takahashi

A total of 14 species in seven tingid genera have been described from the mid-Cretaceous Burmese (Kachin) amber from northern Myanmar, with very distinct paleofauna. Here, a new species of a new genus, Burmavianaida anomalocapitata gen. et sp. nov., is described from Kachin amber. This new species can be readily distinguished from the other described tingid taxa by the apparently smaller body and the structures of the pronotum and hemelytron. Burmavianaida gen. nov. shares the diagnostic characters with two clades composed of three extant subfamilies (Cantacaderinae + Tinginae) and Vianaidinae and may represent an extinct clade distinct from them. To the best of our knowledge, B. anomalocapitata sp. nov. is the smallest species of Tingidae among over 2600 described species. Our new finding supports the hypothesis of the miniaturization phenomenon of insects in Kachin amber, as suggested by previous studies.


2012 ◽  
Vol 26 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Renata Piwowarczyk

Abstract Orobanche coerulescens has a Eurasian distribution. The species is classified as extinct at most of its localities at the western limit of its range. Its populations are very scarce and critically endangered in Central Europe. This work presents the current distribution of O.coerulescens in Poland, based on a critical revision of herbarium and literature data as well as results of original field research, and reviews its distribution in Central Europe (partly in Eastern Europe). Habitats, plant communities, and migration routes of O.coerulescens in Central Europe are discussed. The species was initially known in Poland from now historical localities in Pomerania and the valley of the lower Vistula. In 2000-2011 it was recorded at 9 localities in Podlasie, the Małopolska Upland (Wyżyna Małopolska), and the Łódź Hills (Wzniesienia Łódzkie). Its abundance at the localities ranged from a few to over 1000 shoots. These are the largest populations of O.coerulescens at its western and north-western range limits.


2013 ◽  
Vol 87 (1) ◽  
pp. 105-122 ◽  
Author(s):  
Thomas Saucede ◽  
Alain Bonnot ◽  
Didier Marchand ◽  
Philippe Courville

The discovery of a new species,Cyclolampas altusnew species in the upper Callovian of Burgundy (France) leads to the systematic revision of the rare echinoid genusCyclolampasPomel, 1883. Two morphometric approaches are used jointly to describe and quantify variations in test shape: the analysis of linear measurements and the Elliptic Fourier shape analysis. Both analyses yield congruent results that highlight the amplitude of within-species variations and quantify the part due to allometry. Along with the description ofC. altus, the systematic position of species formerly assigned to the generaPygorhytisPomel, 1883 andCyclolampasis amended. Previously attributed to the genusPygorhytis,Cyclolampas castanea(Desor, 1858) is reassigned to the genusCyclolampason the base of new observations. Conversely, the examination of the Bajocian speciesPygorhytis kiliani(Lambert, 1909) andPygorhytis gillieroniDesor in Desor and de Loriol, 1872, which were previously assigned toCyclolampasnow supports their taxonomic reassignment to the genusPygorhytis. Finally, the two speciesCyclolampas verneuili(Cotteau, 1870) andCyclolampas cotteauiMintz, 1966 (nomen nudum) are considered junior synonyms of the genus type speciesCyclolampas voltzii(Agassiz, 1839). The questioned origin date of the genus, estimated either to the Bajocian or to the Oxfordian, is now clearly established to be upper Callovian. These new results fit well with the overall scheme of atelostomate echinoid evolution and migration to deep-sea environments during the Middle and Upper Jurassic.


2002 ◽  
Vol 59 (12) ◽  
pp. 1845-1850 ◽  
Author(s):  
Luc A Comeau ◽  
Steven E Campana ◽  
Martin Castonguay

The migration patterns of marine fishes are poorly known, in part owing to the technical limitations associated with tracking the movements of animals in deep water. Here we document a large-scale, directed, migration of Atlantic cod (Gadus morhua) off eastern Canada. Our approach was based on the acoustic tagging of 126 fish and the deployment of 69 subsurface receivers, stretching over a 160-km distance along the edge of the Laurentian Channel. After 1 year of automated recording, we found that 65% of the fish migrated out of coastal waters in two distinct runs during the summer–autumn period. The offshore-migrating fish overwintered in deep Laurentian Channel waters, returning inshore in April. Individual migration routes and migration timing were variable, indicating that the cod did not aggregate in large schools during the seasonal migration events.


2018 ◽  
Vol 93 (1) ◽  
pp. 115-125
Author(s):  
John S. Peel

AbstractPhosphatic sclerites of the problematicTarimspiraYue and Gao, 1992 (Cambrian Series 2) recovered by weak acid maceration of limestones display a unique range of mainly strongly coiled morphologies. They were likely organized into multielement scleritomes, but the nature of these is poorly known; some sclerites may have had a grasping function.Tarimspirasclerites grew by basal accretion in an analogous fashion to younger paraconodonts (Cambrian Series 3–4) but lack a basal cavity. Based on proposed homologies,Tarimspiramay provide an extension of the early vertebrate paraconodont–euconodont clade back into the early Cambrian.Tarimspirais described for the first time from Laurentia (North Greenland), extending its known range from China and Siberia in Cambrian Series 2. In addition to the type species,Tarimspira planaYue and Gao, 1992, the Greenland record ofTarimspiraincludes two morphotypes of a new species,Tarimspira artemi.UUID:http://zoobank.org/c7c536c8-cdaf-49a9-ae1d-77c392f553fc.


Author(s):  
О. Mudrak ◽  
G. Mudrak ◽  
V. Serebryakov ◽  
A. Shcherbliuk ◽  
V. Klochaniuk

Based on comprehensive environmental monitoring, geobotanical, zoogeographical, landscape-ecological, hydro-ecological, forest-typological, agroecological principles and approaches and own field research it is proposed to create a national nature park (NNP) «Central Podillya» within Vinnytsia region. A promising NNP is planned to be created on the territory of Vinnytsia and Khmilnytsky administrative districts of Vinnytsia region as a habitat and migration routes of bison (Bison bonasus) and preservation of unique biotic and landscape diversity. The projected area of NPP «Central Podillya» is 53 820 hectares. The need to create a park due to the presence of natural (forest, wetland, peat-swamp, floodplain, meadow, forest-steppe, meadow-steppe, steppe, weed-field) complexes with associations of plant groups, where more than 40 species of plants and lives more than 50 species of animals listed in the RBU, as well as the presence of a significant number of objects that have historical, cultural, recreational, health (medical) value. The general ecological and geographical characteristics of the park from the standpoint of physical-geographical and geobotanical zoning are given. There are 34 objects of the nature reserve fund (NRF), which will be a part of the perspective park. Functional zoning of the territory of the projected NNP «Central Podillya» was carried out taking into account representative and rare ecosystems, where its 4 zones (protected, regulated recreation, stationary recreation, economic) were allocated. The structural elements of the ecological network of the perspective park are singled out. The necessity of protection, preservation and reproduction of biotic and landscape diversity and historical and cultural heritage of the studied territory through the greening of economic activity, education and culture of the local population is substantiated. It was found that the creation of NPP «Central Podillya» through the Presidential Decree and the optimization of protected areas, which account for 2.27% of the total area of Vinnytsia region, the implementation of regional ecological and Emerald networks is an extremely important, important and absolutely necessary for effective adjustment of the strategy of balanced development of territorial communities. Creation of NPP «Central Podillya» will increase the percentage of protected areas to 4.5% of the total area of Vinnytsia region. According to this indicator Vinnytsia region is in one of the last places in Ukraine. According to the Institute of World Resources (Washington), for the effective functioning of the territory, the area of its reserves should be at least 10–12%. Preparation of scientific substantiation and project of creation of NPP «Central Podillya» within Vinnytsia region is a pilot project that requires official detailing, delimitation, land management, coordination with land users on which the park will be located, creation of park directorate, introduction of technologies aimed at preservation and restoration of biogeocenotic cover, reproduction of broken types of connections, preservation of settlements, optimization of land use, balanced development of territorial communities that will be a part of the NNP.


1986 ◽  
Vol 60 (3) ◽  
pp. 606-626 ◽  
Author(s):  
Bruce L. Stinchcomb

Fourteen new species and six new genera of the molluscan class Monoplacophora are described from the Upper Cambrian Potosi and Eminence formations and the Lower Ordovician Gasconade Formation of the Ozark Uplift of Missouri and some new biostratigraphic horizons are introduced. A new superfamily, the Hypseloconellacea nom. trans. Knight, 1956, and a new family, the Shelbyoceridae, are named. The genus Proplina is represented by five new species: P. inflatus, P. suttoni from the Cambrian Potosi Formation, P. arcua from the Cambrian Eminence Formation and P. meramecensis and P. sibeliusi from the Lower Ordovician Gasconade Formation. A new genus and species in the subfamily Proplininae, Ozarkplina meramecensis, is described from the Upper Cambrian Eminence Formation. Four new monoplacophoran genera in the superfamily Hypseloconellacea and their species are described, including: Cambrioconus expansus, Orthoconus striatus, Cornuella parva from the Eminence Formation, and Gasconadeoconus ponderosa, G. waynesvillensis, G. expansus from the Gasconade Formation. A new genus in the new family Shelbyoceridae, Archeoconus missourensis, is described from the Eminence Formation and a new species of Shelbyoceras, S. bigpineyensis, is described from the Gasconade Formation.


2018 ◽  
Vol 92 (6) ◽  
pp. 955-971 ◽  
Author(s):  
Jun Zhao ◽  
Guo-Biao Li ◽  
Paul A. Selden

AbstractA large number of well-preserved chancelloriid scleritomes from the Guanshan biota, early Cambrian of Yunnan, China, are described as a new species,Allonnia tenuisn. sp., and provide solid evidence for the original appearance of these enigmatic animals, based on specimens compacted laterally and top-down. With the assistance of a flexible integument, chancelloriids, especiallyAllonniafrom early and middle Cambrian, may have had the ability to partially or completely expand and contract the body, which might have played an important role in feeding. A new metazoan with single-element spines,Nidelric gaoloufangensisn. sp., is also described. Preservation and affinity are discussed. Detailed comparison of the morphology of the body and spines of this metazoan indicate that it shares many similarities with chancelloriids, of which it may be an unusual form.UUID:http://zoobank.org/2708d95a-1fae-46fc-afea-9707ae97a4d7


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