scholarly journals Brachiopods from the Río del Peñón Formation. Río Blanco Basin, Upper Palaeozoic of Argentina.

2021 ◽  
Vol 15 (2) ◽  
pp. 129
Author(s):  
Gabriela Adriana Cisterna ◽  
Tristán Simanauskas

This paper reviews the brachiopod fauna from the Ríoo de! Peñón Formation, Río Blanco Basin, Upper Palaeozoic of La Rioja province, Argentina. Traditionally, this unit was referred to the Carboniferous, however the braquiopod fauna here studied suggests a new biostratigraphical interpretation, indicating an age range from the latest Carboniferous to Early Permian. Three different brachiopod assemblages can be identified in the section: Assemblage I, from the lower member, includes Streptorhynchus? sp., Dyschrestia? sp., Costatumulus sp. A, Trigonotreta sp., Spiriferellina sp., Orbiculoidea sp., and unidentifiable productids and strophomenids.Assemblage II, from the middle member, includes Tivertonia jachalensis (Amos), Kochiproductus riojanus (Leanza), Costatumulus sp. B, Trigonotreta riojanensis (Lech and Acefiolaza) and Orbiculoidea sp. Assemblage III, from the highest part of the middle member, includes Neochonetes pegnonensis sp. nov., Costatumulus sp. C, Rhynchopora sp., Septosyringothyris jaguelensis Lech, and Orbiculoidea sp. These brachiopod assemblages demonstrate close affinities with faunas from the lower Permian of Western Australia and India. Affinities with faunas from Peru and Texas are less close. 

1990 ◽  
Vol 64 (3) ◽  
pp. 392-399 ◽  
Author(s):  
Brian F. Glenister ◽  
Cathy Baker ◽  
W. M. Furnish ◽  
G. A. Thomas

An ancestral paragastrioceratid, Svetlanoceras irwinense (Teichert and Glenister, 1952), and a specifically indeterminate gonioloboceratid, cf. Mescalites sp., from the basal Callytharra Formation are described as the oldest ammonoids recovered from the Permian of the Carnarvon Basin, Western Australia. Identity of these taxa strengthens correlation with the Holmwood Shale (Sakmarian) of the adjacent Perth Basin. Svetlanoceras moylei Mikesh, n. sp., from the Lenox Hills Formation of West Texas, is described for comparison with other simple paragastrioceratids.


2011 ◽  
Vol 83 (2) ◽  
pp. 471-481 ◽  
Author(s):  
André Jasper ◽  
Dieter Uhl ◽  
Margot Guerra-Sommer ◽  
Abdalla M. B Abu Hamad ◽  
Neli T. G Machado

Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Paraná Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in this area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumption of vegetation by the fire. The presence of inertinite in coals overlying and underlying the tonstein layer indicates that fire-events were not restricted to the ash fall interval. The integration of the new data presented in the current study with previously published data for the Faxinal Coalfield demonstrates that volcanic events that occurred in the surrounding areas can be identified as one potential source of ignition for the wildfires. The presence of charcoal in Permian sediments associated with coal levels at different localities demonstrates that wildfires have been relatively common events in the peat-forming environments in which the coal formation took place in the Paraná Basin.


2021 ◽  
pp. 1-31
Author(s):  
Hai-peng Xu ◽  
Kyi Pyar Aung ◽  
Yi-chun Zhang ◽  
G.R. Shi ◽  
Fu-long Cai ◽  
...  

Abstract The tectonic evolution of the Sibumasu Block during the Permian remains controversial, and Permian faunas and their paleobiogeographic affinities provide some insight into its paleogeographic and tectonic evolutionary histories. In this paper, a new brachiopod fauna dominated by Spinomartinia prolifica Waterhouse, 1981 is described from the uppermost part of the Taungnyo Group in the Zwekabin Range, eastern Myanmar. This brachiopod fauna includes 23 species and its age is well constrained as late Kungurian by the associated conodonts, i.e., Vjalovognathus nicolli Yuan et al., 2016 and Mesogondolella idahoensis (Youngquist, Hawley, and Miller, 1951), contrary to the late Sakmarian age given to the same brachiopod faunas previously reported from southern Thailand and Malaysia. Based on comprehensive comparisons of the Cisuralian brachiopod faunas and other data in different parts of the Sibumasu Block, we consider that they are better subdivided into two independent stratigraphic assemblages, i.e., the lower (earlier) Bandoproductus monticulus-Spirelytha petaliformis Assemblage of a Sakmarian to probably early Artinskian age, and the upper (younger) Spinomartinia prolifica-Retimarginifera alata Assemblage of a late Kungurian age. The former assemblage is a typical cold-water fauna, mainly composed of Gondwanan-type genera, e.g., Bandoproductus Jin and Sun, 1981, Spirelytha Fredericks, 1924, and Sulciplica Waterhouse, 1968. The latter assemblage is strongly characterized by an admixture of both Cathaysian and Gondwanan elements, as well as some genera restricted to the Cimmerian continents. Notably, the spatial distribution pattern of these two separate brachiopod assemblages varies distinctly. The Sakmarian cold-water brachiopod faunas have been found in association with glacial-marine diamictites throughout the Sibumasu Block including both the Irrawaddy and Sibuma blocks. In contrast, the Kungurian biogeographically mixed brachiopod faunas are only recorded in the Irrawaddy Block, unlike the Sibuma Block that contains a contemporaneous paleotropical Tethyan fusuline fauna. Thus, it appears likely that by the end of Cisuralian (early Permian), the Sibumasu Block comprised the Irrawaddy Block in the south with cool climatic conditions, and the Sibuma Block in the north with a temperate to warm-water environment, separated by the incipient Thai-Myanmar Mesotethys.


1989 ◽  
Vol 63 (2) ◽  
pp. 158-181 ◽  
Author(s):  
Calvin H. Stevens ◽  
Barbara Rycerski

Twenty-two species of Early Permian colonial rugose corals belonging to 12 genera from 10 locations in the Stikine River area in northwestern British Columbia, Canada, are described. These include three new species ofFomichevella(F. magna, F. southeri, F. bamberi); two species ofHeintzella; five species ofHeritschioides, of which three are new (H. bagleyae, H. garvinae, H. hoganae); two new species ofParaheritschioides(P. jennyi, P. wickenae); one new species questionably assigned toKleopatrina(K.?stikinensis); two new species ofPetalaxis(P. guaspariniae, P. neriae); and two new species ofLytvophyllum(L.?mongeri, L. wersoni). In addition, five new species assigned to five new genera are here namedEastonastraea complexa, Fedorowskiella simplex, Pararachnastraea lewisi, Stikineastraea thomasi, andWilsonastraea rigbyi.These corals occur in rocks forming part of the Stikine terrane, the largest tectonostratigraphic unit in western Canada. This coral fauna shows a very close affinity with that of the Lower Permian McCloud Limestone of the eastern Klamath Mountains of northern California, and there is some similarity to the Coyote Butte fauna of central Oregon. Several species compare most closely with species from Spitsbergen, but there are few similarities with any cratonal North American faunas and none with Tethyan faunas.


1992 ◽  
Vol 6 ◽  
pp. 131-131
Author(s):  
Peter F. Holterhoff

Cyclothems (fifth - order depositional sequences) are the fundamental stratigraphic motif of the Upper Pennsylvanian and Lower Permian of the North American mid - continent. Through this interval, sequences display an overall second order regression modulated by intermediate frequency sea-level fluctuations. Thus, shelfward incursions of offshore (basinal) facies are more extensive in the lower Upper Pennsylvanian, while merely shoaling facies characterize marine units of many higher sequences.Within basal Upper Pennsylvanian (Missourian) sequences, species of the Erisocrinacea are ubiquitous members of nearshore and offshore crinoid assemblages. However, the species Erisocrinus typus and Delocrinus subhemisphericus display significant ecophenotypic variation between facies: smaller mean and maximum size characterizes offshore/transgressive populations while larger size characterizes nearshore/regressive populations. It is proposed that these are hydrographically - controlled phenotypes: offshore, quiet bottom waters inhibit effective filtration, imposing a metabolic energy threshold beyond which larger morphologies are not viable while nearshore populations are able to assume larger body sizes.Shifting now to the Catacrinidae within the Erisocrinacea, as the frequency of interbasinal drowned shelf conditions waned through the Late Pennsylvanian, new species, inhabiting regressive facies, increased maximum body size and diversity for the family. Thus, lower Virgilian assemblages are highly variable in characteristic size, with smaller, ancestral D. subhemisphericus dominant in offshore facies while robust D. vulgatus, Pyndaxocrinus sp., and Arrectocrinus sp. dominate nearshore facies. Speciation may have involved the stabilization and subsequent diversification of the earlier nearshore phenotype.Through the remainder of the Virgilian and into the Early Permian, near the terminal late Early Permian regression, larger morphologies, represented by D. brownsvillensis, D. vastus, and A. abruptus, dominate midcontinent crinoid assemblages; smaller offshore species had been lost, thus increasing body size for the clade as a whole.Thus, it appears that the same parameters which controlled morphological expression at the fifth - order level (ecophenotypic variation) may also have acted at the second - order level (phylogenetic trend). The interrelationship between sub-cycle and super-cycle sea - level and metabolic viability is paramount to understanding potential morphologies for this clade. However, these factors may not have ultimately influenced clade diversity.


1976 ◽  
Vol 50 (S9) ◽  
pp. 1-261 ◽  
Author(s):  
Richard E. Grant

The Rat Buri Limestone was sampled for silicified brachiopods at 7 localities along the southern peninsula of Thailand. From north to south these localities are: Ban Kao, Khao Phrik, Khao Tok Nam, Khao Chang, Phangnga, Ko Muk NE, and Ko Muk NW. This limestone forms steep monadnocks that project above the alluvium (or the sea at Muk Island), and lacks any clear stratigraphic succession. Fossils indicate that Permian limestones identified throughout Thailand as the Rat Buri range in age from Sakmarian through Kazanian. The brachiopods from the peninsular localities indicate a late Artinskian (Baigendzinian) age and are correlated with the lower Byro Group of Western Australia, the Bitauni fauna of Timor, the upper Amb Formation in the Salt Range of Pakistan, the Lower Permian in the Karakorum Range, and the Trogkofel Limestone of the Karawanken Range in Yugoslavia. Western Hemisphere correlations are with the Copacabana Group of Peru and Bolivia and, very tenuously, with the topmost Cathedral Mountain or the lower Road Canyon Formations in West Texas.Analyses of life habits of the brachiopods indicate the following: Ban Kao lay nearest the Permian shore; the Rat Buri region was under shallow and fairly clear water, perhaps offshore from a reef; Phangnga was a muddy environment with many spiny and attached forms; Ko Muk was also fairly clear, and an especially favorable place for the growth of brachiopods. Sampling efficiency ranges from rather poor (Index .30) to very good (Index .75) with an overall index of .85 for the entire fauna. The Permian Index indicates that these faunas lived under tropical conditions, but the presence of certain genera suggests that seaways were open to Boreal regions.The brachiopod fauna consists of 109 species and 81 genera, of which one family, 15 genera and 71 species are new; 78 of these genera are considered here. The new genera (with family position in parentheses) are:Nematocrania(Craniidae);Demonedys(Chonetidae);Stictozoster(Productellidae);Comuquia, Dyschrestia(Overtoniidae);Incisius(Incisiidae, new family);Caricula, Gratiosina(Marginiferidae);Bibatiola, Celebetes(Chonetellidae);Stereochia(Dictyoclostidae);Litocothia(Lyttoniidae);Goleomyxa(Atriboniidae);Cruricella(Ambocoeliidae);Tipispirifer(Cyrtospiriferidae).Certain genera and species were selected for functional analyses. The lophophore ofIncisiusis interpreted as a filled-in schizolophe. The muscles of the Ambocoeliidae are reconstructed with a set of adjustor muscles designed to raise the shell to allow it to gape. Life position and muscle arrangement ofParalyttonia(and by analogy,Rigbyella)are reconstructed. The mode of growth and possible function of the stegidial plates ofTipispiriferare presented and, in the same vein, previous interpretations are the sequence of growth in the stegidium of the Devonian genusSphenospiraare criticized and analyzed. The cardinalia ofCleiothyridinaare interpreted with regard to muscle attachment, and the apical perforation is compared to the cardinal process of other brachiopods. The lophophore ofChonetinais reconstructed as a ptycholophe whose direction of growth is determined by the position and configuration of the anderidia.Derbyiaand other Orthotetacea are depicted as having attached to the substrate by byssus-like pedicular fibers, and thus were able to cling to loose sediment.


1989 ◽  
Vol 63 (6) ◽  
pp. 919-930 ◽  
Author(s):  
Walter W. Dalquest ◽  
M. John Kocurko ◽  
John V. Grimes

A newly discovered locality of aestivation burrow casts containing the lungfish, Gnathorhiza serrata, is reported from the early Permian Arroyo Formation of Wilbarger County, north-central Texas. Remains preserved in the burrow casts provide sections of mummified Gnathorhiza and new information about the postcranial skeleton of this fish. Scales of Gnathorhiza resemble those of the modern lungfishes such as Lepidosiren in their microanatomy. No traces of paddle-like pectoral or pelvic fins were found and paired fins of Gnathorhiza may have resembled those of Lepidosiren. The axial skeleton and median fins of Gnathorhiza seem to resemble those of Lepidosiren except that the tail area and caudal fin of Gnathorhiza were stout and strong rather than slender and tapering. Gnathorhiza, which aestivated tail-down in its burrow, may have required a stout tail for support.


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