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1.
Rodney Watkins 《Pal?ontologische Zeitschrift》1998,72(1-2):99-109
Eight species of pentamerid brachiopods, assigned toApopentamerus, Capelliniella, Kirkidium, Lissocoelina, Rhipidium, Supertrilobus andStenopentamerus, occur in stromatoporoid-coral reefs of the Silurian (Wenlockian) Racine Formation, Wisconsin and Illinois, USA. One new taxon,Rhipidium kuglitschi n.sp., is described. In contrast to level-bottom communities, where single pentamerid species occur in great numbers over large areas, pentamerids were generally rare members of the Racine reef fauna, and most species have localized distributions. An increase in diversity from one pentamerid species in the north to six species in the south correlates with a southward increase in reef size. Four morphologic groups of pentamerid species differed in the shape of the mantle cavity, which suggests different dynamics of suspension-feeding. Where two or more species are present in single reefs, co-occurrence of these groups represents a partitioning of the pentamerid niche. The relatively high diversity, local distributions, and morphologic distinctions among the Racine pentamerid fauna represent an evolutionary radiation and functional specialization of pentamerids in Wenlock reefs. 相似文献
2.
The lower levels of the Lipeón Formation, in the Eastern Cordillera, north-west Argentina, yield a marine-dominated palynomorph assemblage, together with graptolites of mid to late mid Llandovery age (Demirastrites convolutus and probably Stimulograptus sedgwickii zones). The palynomorph assemblage is dominated by acritarchs, but also contains algae and terrestrial cryptospores. Crassiangulina variacornuta, considered a potentially good global biostratigraphical marker for the Upper Llandovery is recovered for the first time from the Silurian of Argentina. The occurrence of this species in strata not younger than late Aeronian, and independently dated by graptolites, indicates an early first appearance for Crassiangulina variacornuta, in the Lipeón Formation, below the Aeronian/Telychian boundary. The lower part of the unit corresponds to a quiet marine environment; thus supporting that Crassiangulina variacornuta is a facies-sensitive acritarch. 相似文献
3.
《Comptes Rendus Palevol》2014,13(6):483-488
The Chalonnes-sur-Loire outcrop is the most complete Llandovery section in the Ligerian domain (Armorican Massif, NW France); it displays a ca. 10 m-thick sequence of organic-rich black bedded cherts alternating with black graptolitic shales, which were deposited above glaciomarine diamictites of the Hirnantian glaciation. It is likely the black cherts accumulated under eutrophic waters, on the outer shelf part (distal offshore) of a Gondwanan margin, situated at intermediate to high latitudes of the Southern hemisphere. Hydrofluoric acid processing allowed the extraction of radiolarians; seven species are identified in the best preserved sample discovered so far. All seven are common species in tropical assemblages known from Alaska and Nevada, which are characteristic of the Orbiculopylorum assemblage, of Aeronian to early Telychian age. This age is in good agreement with independent age control from graptolites in the Chalonnes section, suggestive of an Aeronian age for the radiolarian-yielding level. 相似文献
4.
Beckemeyer RJ 《ZooKeys》2011,(130):103-110
Nobloedischia rasnitsynigen. et sp. n. (Oedischiidae) is described from the Lower Permian Wellington Formation of Noble County, Oklahoma. The genus is similar to both Petrelcana (Oedischiidae: Mezenoedischiinae) and Oedischia (Oedischiidae: Oedischiinae) and is left unplaced at the subfamily level. The new species is the twelfth Orthoptera species and the fourth species of Oedischiidae from these deposits. 相似文献
5.
Ole A. Hoel 《Pal?ontologische Zeitschrift》2005,79(2):263-284
Strophomenid brachiopods belonging to the generaLeptaena andLepidoleptaena are described from the uppermost Llandovery — Ludlow succession of Gotland, Sweden. In Gotland,Lepidoleptaena comprises the single speciesL. poulseni, andLeptaena includes four species:L. rhomboidalis, L. sperion, L. depressa andL. parvirugata n. sp.L. depressa shows a considerable amount of morphological variation, which is recognised in the two new subspeciesLeptaena depressa visbyensis n. ssp. from the Llandoverian — Wenlockian Visby Formation, andL. depressa lata n. ssp. from the mid-Wenlockian Slite Group. The distribution of the different species is largely substrate-dependent, withLeptaena rhomboidalis andLepidoleptaena poulseni adapted to high-energy environments with firm substrates, whereas the remaining species preferred fine-grained substrates
in low-energy environments.
相似文献
6.
Biotic structure and morphology of patch reefs from South China (Ningqiang Formation, Telychian, Llandovery, Silurian) 总被引:2,自引:0,他引:2
Summary Ningqiang Formation (late Telychian, Llandovery, Silurian), characterized by nearly 3000 m of shales in tercalated with carbonates,
is situated between Ningqiang (S. Shaanxi Province) to Guangyuan (N. Sichuan Province) adjacent to the northwest margin of
the Yangtze Platform. The high diversity “Xiushan Fauna”, and abundant reef development, illustrate a relatively warm and
persistent shallo marine environment in these early Silurian sediments. The sequence shows reef radiation after recovery from
the end Ordovician mass extinction envents. Multiple horizons of reef-building occurred within a relatively short geological
interval and resulted in more than 30patch reefs up to 200 m in diameter and 1–50 m vertically, composed of abundant fossils.
Reef biota include frame-building corals, stromatoporoids, bryozoans, and microbialites, and reef-associated oranisms such
as crinoids, brachiopods, trilobites, gastropods, nautiloids and ostracods. Three reefrelated biotic associations are recognised:
a) reefs dominated by framework with crinoids and microbia; b) reefs dominated by only crinoids and microbia; and c) crinoiddomainated
facies. Seven representative reef examples illustrate different morphologies and growth styles. A high terrigenous debris
input and shallow epicontinental ramp, which lacked obvious topographic variation, were major controls which resulted in rather
simple reefs; sedimentation was apparently the main constraint on lateral and vertical extension of reefs, and prevented large-scale
reef complexes developing. 相似文献
7.
The Platanaceae holds a basal position in the phylogeny of eudicots and therefore is of great interest to angiosperm systematists. The fossil record of the family is found in strata ranging from the Cretaceous to Recent in America, Europe and Asia. The research on the Platanaceae in the Dakota Formation can be traced back to 19th century; however, mesofossils of reproductive organs of the Platanaceae were never reported in the Midwest of North America before. This paper reports several specimens of Friisicarpus (Platanaceae) from the Dakota Formation in Kansas, USA. It complements the existing fossil records, and provides more information on reproductive biology of the family. The comparison with similar fossils from eastern North America and Europe provides some hints on biostratigraphy of the Cretaceous. 相似文献
8.
Bryozoans from the Mitikha Formation (Lower Famennian, Upper Devonian) of the Kuznetsk Basin, Russia
Z. A. Tolokonnikova 《Paleontological Journal》2012,46(4):354-359
Bryozoans from the Mitikha Formation (Lower Famennian, Upper Devonian) in the Kuznetsk depression are described for the first time. This bryozoan assemblage comprises both the well-known species Leioclema numerosum Moroz., L. ramosum Nekh., and Nicklesopora graciosa Troiz. and new taxa: L. kusmense sp. nov. and Megacanthopora glubokaensis sp. nov. The bryozoan assemblage contains some species common with the Famennian bryozoan assemblage of Kazakhstan. 相似文献
9.
The most complete angiospermous palynological assemblage for the middle-earliest late Albian of north-eastern Spain is reported from the Middle Member of the Escucha Formation at the San Just site. Nine palynological samples yielded mainly monosulcates (Clavatipollenites, Dichastopollenites, Hammenia, Jusinghipollis, Liliacidites, Pennipollis including proposed new species P. escuchensis, Retimonocolpites, and Transitoripollis) and a few tricolpates (Phimopollenites, Rousea, Striatopollis, and Tricolpites). These assemblages, mainly composed of angiosperm pollen grains, suggest that significantly diversified flowering plants flourished both in brackish and freshwater swamp plain environments represented by the Escucha Formation in Albian times, although they were less diverse than angiosperms in the Late Cretaceous. The palynological assemblages share greatest similarities with those of other southern Laurasian localities, although there are some taxa more typical of palynofloras of northern Gondwana. 相似文献
10.
The stratigraphy of the Carboniferous Iraty Formation is described in several sections from the southwestern Alduides-Quinto Real Massif (western Pyrenees), and biostratigraphy is updated based on conodont occurrences. The Ochaverri Member yields upper Serpukhovian conodonts, whereas the lower part of the overlying Asturreta Member is assigned to the lower Bashkirian, according to the occurrences of Declinognathodus noduliferus bernesgae and D. n. noduliferus, respectively. The upper beds of the formation (Baserdi Member) are correlated with the Kinderscoutian to lowermost Marsdenian English substages (lower Bashkirian), and new conodont occurrences are the oldest species of Neognathodus and Idiognathodus known in Spain. We discuss the status of Idiognathoides macer, several species related to I. sinuatus, I. sulcatus and Lochriea glaber. Conodont diversity is related to stratigraphic distribution of species and conodont biofacies. Finally, the lowermost Marsdenian to upper Bashkirian age of the siliciclastic rocks overlying the Iraty Formation is also discussed and compared with known data from localities in the western Pyrenees. 相似文献
11.
Michael Fastnacht 《Pal?ontologische Zeitschrift》2001,75(1):23-36
The anterior tips of associated upper and lower jaws of a pterosaur from the Lower Cretaceous of Brazil are described and assigned to the taxonColoborhynchus in the family Ornithocheiridae. It is characterized by the shape and position of the sagittal crest on the upper and lower jaw, the arrangement and length of the teeth and the spoon-like lateral expansion of the anterior parts of the jaws. It closely resemblesColoborhynchus wadleighi from North America andColoborhynchus clavirostris from England. Diagnostic anatomical characteristics permit a revision of the genusTropeognathus, which is shown here to be a junior synonym of other described taxa.Tropeognathus mesembrinus is referred toCriorhynchus andT. robustus toColoboryhnchus. Consistent anatomical features enable the new jaw fragment to be assigned toColoborhynchus robustus. 相似文献
12.
Lower Permian Bryozoan fauna of Jamal Formation, exposed in Bagh-e Vang (Shotori Mountains, northeast Iran) includes six species.
Three species – Streblotrypa (Streblascopora) marmionensis (Etheridge 1926), Rhabdomeson bispinosum (Crockford 1944) and Alternifenestella kungurensis (Stuckenberg 1898) – indicate the Lower Permian (Artinskian to Kungurian) age of the formation. Three additional taxa – Fistulipora sp. 1, Fistulipora sp. 2 and undetermined timanodictyid bryozoan ?Timanodictya sp. could not be identified at the species level. The investigated fauna refers to Uralian and Australian palaeobiogeographic
provinces. 相似文献
13.
Relatively large tetrapod footprints from Lower Pennsylvanian strata of the Pottsville Formation in the Warrior basin coal field of Alabama were previously assigned to the ichnogenus Attenosaurus. However, three morphotypes are present, and we assign these tracks to Attenosaurus, a new ichnogenus (Alabamasauripus) and Dimetropus. Most of these tracks apparently were made by large pelycosaurs, for which there is no bone record older than Late Pennsylvanian. 相似文献
14.
Basal titanosauriform (Dinosauria, Sauropoda) teeth from the Lower Cretaceous Yixian Formation of Liaoning Province, China 总被引:1,自引:0,他引:1
The Yixian Formation of Liaoning Province, People's Republic of China has yielded a diverse fauna of non-avian dinosaurs, but is dominated by small-bodied taxa. Here, we describe a series of isolated teeth from the Lujiatun Beds of the formation that are referable to a basal titanosauriform sauropod. Some of the teeth possess a distinctive circular boss on the lingual surface, which suggests that they are referable to cf. Euhelopus sp. This identification provides some additional support for biostratigraphical correlations between the Jehol Group and the Mengyin Formation of Shandong Province that suggest an Early Cretaceous age for the latter unit. Moreover, the titanosauriform affinities of the teeth provide further evidence for the dominance of this sauropod clade in eastern Asia during the Cretaceous. 相似文献
15.
The distribution of Osprioneides is more environmentally limited than that of Trypanites in the Silurian of Baltica. Osprioneides probably occurred only in large hard substrates of relatively deepwater muddy bottom open shelf environments. Osprioneides were relatively rare, occurring in 4.7% of all stromatoporoid specimens in that environment, in contrast to small Trypanites-Palaeosabella borings, which occur in 88.4% of stromatoporoids and 88.9% of heliolitid corals. Osprioneides is reported only from the lower Sheinwoodian stromatoporoids of the exposed Silurian of Saaremaa (Wenlock to Pridoli). Osprioneides borings probably played a minor role in the general bioerosion in the Silurian of Baltica. 相似文献
16.
Lower Cambrian calcareous microfossils that preserved monospores and basal attachment organs with rhizoids have been discovered in jaspers of the Karakatty Formation of the Northern Tien Shan. A new genus, Koroleviphyton Kolosov, is established in the red algae division Rhodophyta with the type species K. attenuescens (Kolosov, 1983). 相似文献
17.
18.
SEAN P. ROBSON BRIAN R. PRATT 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2007,40(1):19-32
One hundred and twenty-five linguliformean brachiopods of late Marjuman (Cambrian) age with shell perforations, presumably caused by predation, were recovered from shallow-water limestones at two localities of the Deadwood Formation in the Black Hills of South Dakota, USA. Three-quarters of the perforated valves belonged to taxa in the order Acrotretida, while one-quarter of the specimens belonged to those of the order Lingulida. This is the first report of predation of fossil lingulids. In both orders there was a marked selection for valve type. Ninety-five per cent of all perforations of acrotretids were in the ventral valve, while 87% of all perforations of lingulids were in the dorsal valve. The highest rate of predation of collected acrotretids, at any stratigraphic horizon, was 22%, while the rate of predation of collected lingulids, at any given stratigraphic horizon, was as high as 9%. Half of the perforated valves had round holes with a sharp, non-beveled exterior edge, and half had irregularly shaped holes with chipped interior edges. The former type is attributed to either boring or a swift, piercing percussive strike, while the latter is attributed to a smashing percussive strike with a blunt appendage. A third type of perforation consisting of minute, roughly circular holes is thought to be too small to be the work of predators, and is assumed to be the result of an encrusting organism or parasite. The different types of perforation seen in the brachiopod valves indicate that there was more than one type of predator attacking them, including possibly one of the earliest durophages. Various hypothetical predators are suggested as potential candidates for causing the shell perforations. The criteria for their selection as possible linguliformean predators include possessing the ability to produce one of the two types of shell perforation, and being small enough to warrant preying on small (< 2 mm) brachiopods. 相似文献
19.
Gillbeea whypallana sp. nov. is described from the Wet Tropics of North Queensland. This species differs from G. adenopetala in the larger serrate asymmetrical stipules, hirsute leaves and fruits and the number of lateral veindleaflet. Gillbeea adenopetala and G. whypallana both differ from G. papuana in having hairs on the lateral margins of the petals, and in having more than two ovules per carpel. The comparative morphology of the three Gillbeea species is described and illustrated, and the phylogenetic placement of the genus within the Cunoniaceae is discussed briefly. 相似文献