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1.
Anne M. Sørensen Lars Stemmerik 《Palaeogeography, Palaeoclimatology, Palaeoecology》2007,251(2):198-209
Late Permian bryozoans from the Wegener Halvø, Ravnefjeld and Schuchert Formations in East Greenland have been investigated. 14 genera are recognised.Integration of the new bryozoan data from the Upper Permian of East Greenland with data on the distribution of Permian bryozoans along the northern margin of Pangea is used to test hypotheses concerning Late Palaeozoic evolution of the North Atlantic region. During the Permian, the Atlantic rift system formed a seaway between Norway and Greenland from the boreal Barents Shelf to the warm and arid Zechstein Basin. This seaway is considered to be the only marine connection to the Zechstein Basin and therefore the only possible migration route for bryozoans to enter the basin. The distribution of Permian bryozoans is largely in keeping with such a connection from the cool Barents Shelf past the East Greenland Basin to the warm Zechstein Basin and also corroborates the change in temperature through this connection. 相似文献
2.
From the Late Permian Zechstein reefs (Lopingian: Wuchiapingian) of eastern Thuringia, Germany, the new ophiocistioid goniodont Linguaserra spandeli sp. nov., is described, figured, and discussed, within the Linguaserridae Reich and Haude, 2004. The (para)genus Linguaserra is redefined; the stratigraphical and regional distribution as well as the phylogenetic position are briefly discussed. Linguaserra spandeli sp. nov. is the stratigraphically youngest record of this echinoderm group (Echinozoa: Ophiocistioidea) worldwide. 相似文献
3.
We present a preliminary report on the first diverse central European assemblage of Late Permian terrestrial tetrapods from a fissure-filling in marine sediments of the lower Zechstein near Korbach (northwestern Hesse, Germany). It includes therapsids (cynodonts and dicynodonts), archosauromorph diapsids, and pareiasaurs. Similar assemblages were previously known only from the Upper Permian of Russia, Scotland, and South and East Africa. The occurrence of the basal cynodontProcynosuchus is paleobiogeographically significant because this taxon was previously known only from theDicynodon lacerticeps-Whaitsia assemblage zone of South Africa and the Madumabisa Mudstone of Zambia. The geological context of the Korbach site permits a rather precise chronostratigraphic placement of the tetrapod assemblage in the interval between Zechstein 1 and 3. The Korbach tetrapod assemblage is late Tatarian in age. 相似文献
4.
New ammonoid species of the genus Araxoceras (A. abarquense sp. nov. and A. iranense sp. nov.) are described from the Early Dzhulfian (Early Wuchiapingian) beds of the Hambast Formation of Central Iran (Abade).
The data on the distribution of Paraceltites (Paraceltites sp.) and Vedioceras (V. umbonovarum Ruzhencev), for the first time discovered in the Dzhulfian beds of Abade, and of Eoaraxoceras are provided. The correlation of the Late Permian assemblages of ammonoids of Iran and Transcaucasia is amended. 相似文献
5.
A. V. Minikh 《Paleontological Journal》2006,40(5):564-571
New Late Permian fishes combining features characteristic of several classes are analyzed and redescribed. They were assigned to the family Discordichthyidae of the order Discordichthyiformes comprising three genera and four species: Mutovinia stella Minich, Geryonichthys longus A. Minich, G. burchardi A. Minich, and Discordichthys spinifer A. Minich (Minikh, 1998). A new species, Mutovinia sennikovi sp. nov., is described. Due to rapid evolutionary replacement, discordichthyids are rather useful stratigraphically. The photographs of the skeleton and membrane bones of these fishes are published for the first time. 相似文献
6.
Summary The Upper Permian Zechstein 2 Carbonate (Stassfurt Carbonate, or Ca2) platform facies of Northwest Germany can be subdivided
into twelve subfacies types using slabbed cores from fifteen representative wells. Thin section and scanning microscopic analysis
further provide subfacies-specific characteristics, based on distribution, size, shape, and spatial arrangement of the grains
contained in the different subfacies types. Thirteen grain types can be distinguished within the different subfacies types
on the Ca2-platform: 1) one type of oncoid, 2) one type of grapestone, 3) three types of peloids, 4) four types of ooids and
5) four types of aggregate grains. Both presence and composition of grains are indicative of the different subfacies types.
There is also a relation between grain composition and porosity of the Ca2-subfacies types. The size and quantity of ooids
correlate positively with increasing porosity, whereas an increasing amount of algal structures (algal-lamination) correlates
negatively with porosity.
The Ca2-platform carbonates almost exclusively represent highstand systems tract and lowstand systems tract deposits. The
presence or absence of type-3 aggregate grains within the grainy shoal and algal-laminated shoal subfacies allows the assignment
of these subfacies to highstand (grains absent) or lowstand (grains present) systems tracts deposits. The Ca2-highstand deposits
can be subdivided into four shallowing-upward parasequences (PS3 to PS7) bounded by parasequence boundaries (PSB3 to PSB6)
and Zechstein sequence boundary ZSB4.
In contrast to macroscopic core studies, microscopic studies to identify Ca2-subfacies types can utilize cutting material.
This allows reconstruction of the subfacies distribution on the Ca2-platform, and delineation of potentially porous zones
in uncored Ca2 intervals. 相似文献
7.
A new species of Tococladidae CARPENTER, 1966 from the Permian of France (Insecta: Archaeorthoptera)
A new forewing venation pattern of the Tococladidae is proposed and the phylogenetic affinities of this family are discussed, based on Tococladus garrici nov. sp. This fossil comes from the Salagou Formation (Permian, Saxonian Group, Lodève basin, France). The Tococladidae is assigned to the Archaeorthoptera BÉTHOUX and NEL, 2002. The biostratigraphic implications of this discovery are briefly discussed, but it is still not possible to infer any definite conclusion about the age of this formation. 相似文献
8.
A new species of Discinites is described from the Late Permian Upper Shihhotse Formation of the Weibei Coalfield, Shaanxi Province, China. D. hanchengensis sp. nov. has decurrent and disk-like sporophylls with deep-toothed apices, elliptical sporangia and rectangular epidermal cells. The spores are generally of the Calamospora type. The megaspores and microspores are 300–380 and 45–90 μm in diameter, respectively. The microspores are similar in size to those of all other species of Discinites that contain Calamospora, but the megaspores are remarkably smaller. The new species represents the first record of Discinites with Calamospora from China and from the Cathaysian flora. Finally, we summarize the associated foliages of Discinites in the Cathaysian flora and find that they are all markedly different from those found in the Euramerican flora. 相似文献
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10.
《Comptes Rendus Palevol》2005,4(6-7):517-530
Previous research indicated that ammonoid taxonomic diversity exploded after the Late Permian mass extinction, regaining pre-extinction levels by the Late Induan (Dienerian substage). From taxonomic analyses it had been inferred that ammonoids recovered rapidly, relative to other marine invertebrate groups. Complementing taxonomic metrics with morphologic and spatial data revealed more complex recovery dynamics. Morphological analysis indicated that ammonoids did not fully recover until the Spathian or Anisian. Taxonomic diversity is a poor predictor of disparity during the recovery. Spatial partitioning of taxonomic and morphological diversity revealed spatially homogeneous recovery patterns. Combining taxonomic, morphological, and spatial data refined interpretations of Triassic ammonoid recovery patterns and indicated that ecological, not intrinsic, factors were the probable control on ammonoid recovery rates. To cite this article: A.J. McGowan, C. R. Palevol 4 (2005). 相似文献
11.
Evolutionary trends in Late Permian Darwinulocopina are summarised with reference to extensive collections from eastern European Russia, from the White Sea in the North to the Cis-Caspian in the South. They inhabited large, shallow lakes in which the variety of habitats was favourable for high ostracod diversity. Three superfamilies are represented: the Darwinuloidea preferred lakes with terrigenous sedimentation and insignificant bicarbonate, the Suchonelloidea inhabited lakes with increased bicarbonate and could also live in low-sulphate waters, and the Darwinuloidoidea inhabited high-bicarbonate water bodies and could also survive in low-magnesium waters. Different evolutionary trends account for the different ages of the crucial stages of development of each superfamily: the beginning of the mid-Tatarian for the Darwinuloidea, the late Tatarian for the Suchonelloidea and Darwinuloidoidea. 相似文献
12.
The composition of the diatom community on the bryozoans Electra pilosa, Membranipora membranacea, Flustra foliacea, and Alcyonidium gelatinosum from the German Bight was studied by light and scanning electron microscopy. In total, members of 26 diatom genera were found,
with Cocconeis, Tabularia, Licmophora, Amphora, and Navicula being the most abundant. The amount and the composition of the diatom covering seem to be typical for single bryozoan species.
Electra pilosa and Membranipora membranacea showed a rather dense covering with 71–547 cells/mm2 and 77–110 cells/mm2, respectively. The most prominent genus on Electra pilosa was Cocconeis, reaching up to 58% of all diatoms in one sample, followed by Navicula, Tabularia and Amphora. The most abundant genera on Membranipora membranacea were Tabularia and Licmophora, making up almost 70% of all diatoms in one sample, followed by Navicula, Cocconeis and Amphora. The diatom composition was very stable on all Electra samples, but varied on Membranipora samples. With <1–27 cells/mm2, diatoms were much less abundant on Alcyonidium gelatinosum. Members of the genera Tabularia and Navicula were the most frequently found benthic diatoms, whereas the planktonic forms Coscinodiscus, Cyclotella, and Thalassiosira made up 35% of the diatoms. On Flustra foliacea, diatoms were virtually absent, with fewer than 5 cells/mm2. The low diatom numbers are probably due to toxic metabolites produced by the host. The same may be true for Alcyonidium gelatinosum, but here they might also be a consequence of the surface properties of the bryozoan.
Electronic Publication 相似文献
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14.
A. G. Ponomarenko 《Paleontological Journal》2006,40(3):295-296
Taldycupes rosanovi sp. nov. is described from an isolated elytron from the locality of Ilimpeya, Krasnoyarsk Krai, Tunguska River basin, Limptekon Formation. 相似文献
15.
Sanghamitra Ray 《Palaeontology》2000,43(2):375-405
The Kundaram Formation, a Lower Gondwana unit of the Pranhita-Godavari valley, contains the only known Permian dicynodonts in India. This dicynodont assemblage is dominated by Endothiodon. Two species (Endothiodon mahalanobisi sp. nov and Endothiodon uniseries Owen 1879) are described here. This is the first detailed study of Endothiodon from outside Africa. The study shows that Endothiodon jaw articulation permitted propalinal action when the opposing serrations in the upper and the lower jaw teeth occluded with the horn covered areas and helped in shearing and mastication. The presence of oblique wear facets on the upper and lower jaw teeth and a masseter-like muscle suggest a slightly lateral movement of the lower jaw which enhanced slicing of plant matter. A robust stapes with posterolateral notch constitutes the middle ear region though Endothiodon depended mainly on ground vibrations for hearing. Other features included a reduced olfactory sense and large eyes for vigilance and ease of detecting predators. Based on its vertebrate fauna, this fossiliferous Gondwana horizon of the Pranhita-Godavari valley is broadly correlated with the Tropidostoma and/or Cistecephalus Assemblage Zones of the Beaufort Group, Karoo Supergroup, South Africa. It indicates a probable Tatarian age for the Kundaram Formation. 相似文献
16.
Representatives of nine bryozoan genera of four orders are identified for the first time from the carbonate deposits of the stratotype section of the Upper Kazanian Substage of the Middle Permian. Among them four new species are established and described: Permopora volgensis sp. nov., Stellahexaformis burovi sp. nov., Alternifenestella esaulovae sp. nov., and Wjatkella definita sp. nov. A brief lithological characterization is provided of the carbonate deposits that contain the remains of these bryozoans and were formed under the conditions of transgression-regression cycles of the Late Kazanian marine basin. Some questions concerning the taphonomy, ecology, and morphology of the bryozoans studied are considered. 相似文献
17.
We describe a new species of rail from the Sawmill Sink blue hole on Abaco Island in the northern Bahamas. Known from abundant, beautifully preserved Late Pleistocene fossils, Rallus cyanocavi sp. nov. was a medium-sized, flightless species that probably was endemic to the Little Bahama Bank, which is a carbonate platform surrounded by deeper water. We are uncertain whether R. cyanocavi survived into the Holocene, when higher sea levels transformed the Little Bahama Bank from a single large, Late Pleistocene island (ca. 12000 km2) to the scattering of smaller islands seen today, the largest of which is Abaco (1681 km2). Fossils of additional extinct, flightless species of Rallus probably await discovery on some of the 21 other carbonate banks that span the Bahamian Archipelago. 相似文献
18.
Goryunovia hemiseptata n.gen. n.sp. is an unusual Lower Ordovician cyclostome bryozoan, represented by a single colony from the Middle Volkhov Stage (Arenig) of the Leningrad Oblast. The encrusting uniserial colony consists of large, slender zooids, many with closely-spaced partial diaphragms (hemisepta), and has a distinctive trichotomous branching pattern. Skeletal organization is of the sagenellid grade: calcified interior walls appear to be present, and the exterior frontal walls lack pseudopores. As details of microstructure and early astogeny are unknown, it is difficult to interpret the phylogenetic relationships ofGoryunovia until further material is forthcoming. However, there is some resemblance with the enigmatic hederellids, which appear in the Upper Silurian and possibly range into the Triassic. 相似文献
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20.
T. N. Smirnova 《Paleontological Journal》2009,43(2):142-152
Based on the study of the ontogenetic changes of cardinalia and brachidium in the genera Beecheria Hall et Clarke, 1893 and Calycelasma Smirnova, 2007 (family Beecheriidae), a complex development of the brachidium, which corresponds to the angustothyridid type, and the formation of crural plates, which functioned as the outer hinge plates at the early developmental stages, are revealed. 相似文献