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Tytuł:
Small shelly fossils from the argillaceous facies of the Lower Cambrian Forteau Formation of Western Newfoundland
Autorzy:
Skovsted, C.B.
Peel, J.S.
Powiązania:
https://bibliotekanauki.pl/articles/20504.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Brachiopoda
Cambrian
Forteau Formation
geological setting
Helcionellidae
Hyolitha
Lower Cambrian
Newfoundland
argillaceous facies
brachiopod
facies
fossil
helcionelloid mollusc
hyolith
mollusc
paleontology
small shelly fossil
systematics
Opis:
A diverse fauna of helcionelloid molluscs, hyoliths, and other small shelly fossils is described from limestone layers within the Forteau Formation of the Bonne Bay region in western Newfoundland. The fauna is dominated by internal moulds of various molluscs and tubular problematica, but also includes hyolith opercula, echinoderm ossicles, and other calcareous small shelly fossils preserved by phosphatisation. Originally organophosphatic shells are comparatively rare, but are represented by brachiopods, hyolithelminths, and tommotiids. The fauna is similar to other late Early Cambrian faunas from slope and outer shelf settings along the eastern margin of Laurentia and may be of middle Dyeran age. The similarity of these faunas indicates that at least by the late Early Cambrian, a distinctive and laterally continuous outer shelf fauna had evolved. The Forteau Formation also shares elements with faunas from other Early Cambrian provinces, strengthening ties between Laurentia and Australia, China, and Europe during the late Early Cambrian. Two new taxa of problematic fossil organisms are described, the conical Clavitella curvata gen. et sp. nov. and the wedge−shaped Sphenopteron boomerang gen. et sp. nov.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Early Cambrian [Botomian] stem group brachiopod Mickwitzia from Northeast Greenland
Autorzy:
Skovsted, C B
Holmer, L.E.
Powiązania:
https://bibliotekanauki.pl/articles/22580.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ontogenesis
brachiopod
shell structure
Greenland
Cambrian
Mickwitzia
Brachiopoda
paleontology
Botomian
Opis:
The problematic brachiopod Mickwitzia Schmidt, 1888 is re−described based on new material of M. cf. occidens Walcott, 1908 from the Early Cambrian (Botomian) Bastion and Ella Island formations of Northeast Greenland. Etched material demonstrates that Mickwitzia has a lingulid−like juvenile (“larval”) shell with trails of nick−points, reflecting the movement of marginal setae. Juvenile and early mature ventral valves have a lingulid−like pseudointerarea with a pedicle groove. The shell of M. cf. occidens is only partially phosphatic, in particular around the juvenile–early mature shell in both valves. The phosphatic shell includes at least two types of cylindrical structures: (1) slender columns identical with the columns of acrotretoid brachiopods and (2) relatively thicker tubes which may be open to the exterior surface and have internal striations (on the ventral pseudointerarea). The striations are most likely imprints of microvilli and these tubes can be inferred to have contained setae. The thinner linguliform columns and thicker setigerous striated tubes are considered to be homologous with identical structures in the sellate and mitral sclerites of the problematic Micrina, which has been identified as a probable primitive stem group of the Brachiopoda. Mickwitzia represents a more derived member of the stem group Brachiopoda.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hyoliths and small shelly fossils from the Lower Cambrian of North-East Greenland
Autorzy:
Malinky, J M
Skovsted, C.B.
Powiązania:
https://bibliotekanauki.pl/articles/21690.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Hyolitha
Orthothecida
fossil
Hyolithida
Bastion Formation
Greenland
Lower Cambrian
paleontology
Botomian
Opis:
The hyolith assemblage from the Lower Cambrian Bastion Formation of North−East Greenland is significant in that it contains several hyolith taxa that possess traits of both orders Hyolithida and Orthothecida. They possess morphological traits that seem to be characteristic of the ancestral forms of both groups. In addition, many hyolith taxa from this interval are globally distributed, supporting the notion that these fossils have potential as stratigraphic indicators. This assemblage contains genera and/or species seen in Australia, North America, the Siberian Platform, and South China. Hyoliths identified include the hyolithids Parkula bounites, Hyptiotheca karraculum, Microcornus eximius, M. petilus, Paracornus poulseni gen. et sp. nov., as well as Similotheca similis?, S. bastionensis sp. nov., and S. groenlandica sp. nov.; two opercula remain in open nomenclature. Orthothecids from this assemblage are one unnamed species each of Contitheca and Gracilitheca. Large, macro−sized hyoliths from the same formation described by Poulsen (1932) are mostly unidentifiable, although an operculum formerly identified as Hyolithes (Orthotheca) communis is reassigned to Hyptiotheca. Problematic organisms of uncertain affinity include Cupitheca holocyclata, Conotheca australiensis, an unnamed species of Coleolus, and the cap−shaped Cassitella baculata gen. et sp. nov. that may be an operculum of some as yet unknown organism. Missarzhevsky (1969) used Hyolithes(Orthotheca) bayonet var. groelandicus and H. (O.) bayonet var. longus as the basis for Lenatheca, but the specimens on which that genus is based are too poorly known for a proper diagnosis of Lenatheca.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Soft-part preservation in a linguliform brachiopod from the lower Cambrian Wulongqing Formation [Guanshan fauna] of Yunnan, South China
Autorzy:
Hu, S
Zhang, Z.
Holmer, L.E.
Skovsted, C.B.
Powiązania:
https://bibliotekanauki.pl/articles/20740.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
preservation
linguliform brachiopo
Lower Cambrian
Cambrian
Wulongqing Formation
Yunnan Province
South China
brachiopod
Linguliformea
benthic community
China
Opis:
Linguliform brachiopods were important components of early Cambrian benthic communities. However, exceptionally preserved soft parts in Cambrian linguliform brachiopods are extremely sparse, and the most important findings are from the early Cambrian Chengjiang Konservat Lagerstätte of Kunming, southern China. Here we describe the first record of preserved soft−part anatomy in a linguliform brachiopod from the early Cambrian Guanshan fauna (Wulongqing Formation, Palaeolenus Zone); a unit which is considerably younger than the Chengjiang fauna. The well preserved soft anatomy include linguliform pedicles, marginal setae and, in a few cases, an intact lophophore imprint. The pedicle has pronounced surface annulations, with its proximal−most part enclosing the apex of the ventral pseudointerarea; the pedicle is up to 51 mm long, corresponding to more than 4 times the sagittal length of the shell, and 12% of the maximum valve width. In details of their preservation, these new fossils exhibit striking similarities with the linguliforms from the older Chengjiang fauna, and all specimens are preserved in a compressed state as flattened impressions. The new linguliform has an elongate oval to subtriangular shell and an elongate triangular ventral pseudointerarea; the pedicle emerged from an apical foramen through a poorly preserved internal pedicle tube. The new linguliform is most similar to the mostly organic−shelled siphonotretoid−like brachiopod Acanthotretella spinosa, recently described from the classic middle Cambrian Burgess Shale Konservat Lagerstätte, British Columbia, Canada. The new species Acanthotretella decaius sp. nov. is described; it differs from A. spinosa in having a slightly thicker pedicle, and a larger and more rigid, probably partly mineralised shell, indicating that the mostly organic shell of A. spinosa may represent a secondary reduction of shell mineralisation. However, the spine−like setae of the new species are unfortunately poorly preserved only at the margin of the shell, but the new species is referred tentatively to the Superfamily Siphonotretoidea. The occurrence of A. decaius in the Guanshan fauna is the first lower Cambrian (Series 2, early Stage 4) record of both Acanthotretella and siphonotretoids, and it represents the first description of a lophophore and digestive tract from the siphonotretoid lineage.
Źródło:
Acta Palaeontologica Polonica; 2010, 55, 3; 495-505
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The problematic early Cambrian fossil Tumulduria incomperta represents the detached ventral interarea of a paterinid brachiopod
Autorzy:
Skovsted, C.B.
Kouchinsky, A.
Bengtson, S.
Holmer, L.E.
Powiązania:
https://bibliotekanauki.pl/articles/946021.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopoda
problematica
tommotian stage
terreneuvian
cambrian
siberia
Opis:
The organophosphatic early Cambrian (Terreneuvian, Cambrian Stage 2) fossil Tumulduria incomperta has been problematic ever since its original description in 1969. Comparison of abundant specimens from the Lower Cambrian of Siberia with co-occurring brachiopod valves show that T. incomperta represents the central portion of the ventral interarea of a paterinid brachiopod similar to Cryptotreta neguertchenensis, and that the domed central portion of typical Tumulduria specimens represents the ridge-like pseudodeltidium of the interarea.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 2; 359-365
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The tommotiid Camenella reticulosa from the Early Cambrian of South Australia: morphology, scleritome reconstruction, and phylogeny
Autorzy:
Skovsted, C B
Balthasar, U.
Brock, G.A.
Paterson, J.R.
Powiązania:
https://bibliotekanauki.pl/articles/21581.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
tommotiid
paleontology
Camenella reticulosa
Early Cambrian
Cambrian
South Australia
Australia
morphology
scleritome reconstruction
phylogenesis
Tommotiida
scleritome
Atdabanian
Botomian
sclerite
Opis:
The tommotiid Camenella reticulosa is redescribed based on new collections of well preserved sclerites from the Arrowie Basin (Flinders Ranges), South Australia, revealing new information concerning morphology and microstructure. The acutely pyramidal mitral sclerite is described for the first time and the sellate sclerite is shown to be coiled through up to 1.5 whorls. Based on Camenella, a model is proposed by which tommotiid sclerites are composed of alternating dense phosphatic, and presumably originally organic−rich, laminae. Camenella is morphologically most similar to Lapworthella, Kennardia, and Dailyatia, and these taxa are interpreted to represent a monophyletic clade, here termed the “camenellans”, within the Tommotiida. Potential reconstructions of the scleritome of Camenella are discussed and although a tubular scleritome construction was recently demonstrated for the tommotiids Eccentrotheca and Paterimitra, a bilaterally symmetrical scleritome model with the sclerites arranged symmetrically on the dorsal surface of a vagrant animal can not be ruled out.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 3; 525-540
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First record of a Jurassic mammal [?'Peramura'] from Ethiopia
Autorzy:
Clemens, W A
Goodwin, M.B.
Hutchison, J.H.
Schaff, C.R.
Wood, C.B.
Colbert, M.W.
Powiązania:
https://bibliotekanauki.pl/articles/21748.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Ethiopia
tooth fragment
first record
mammal
Peramura
Mammalia
Jurassic
Mugher Mudstone
paleontology
Opis:
The first record of Mesozoic mammals in Ethiopia is a fragment of a lower mammalian molar discovered in residues left after acid dissociation of a small (ca. 4 kg) geological hand sample of a fine−grained bone bed in the lower part of the Mugher Mudstone exposed in the valley of the Jema River. This bone bed is part of a series of estuarine to fluvial deposits that are thought to be of Late Jurassic (Tithonian) age. The fragment preserves the trigonid of a molar; the distal part of its crown is missing. Morphological characters of the trigonid indicate the specimen (JEM−5/21) documents the presence of a mammal with a dentition at either a derived pretribosphenic or primitive tribosphenic grade of evolution. Absence of a well developed basal cingulid around the mesial end of the crown argues against phylogenetic relationships to the australosphenidans. Loss of the distal portion of the crown removed characters critical for determining its grade of evolution. The working hypothesis that JEM−5/21 represents a “peramuran” is advanced for testing. Hypotheses that it represents a mammal with a more derived grade of molar evolution or a previously unknown group of mammals cannot be excluded. JEM−5/21 establishes the presence of mammals in Ethiopia during the Late Jurassic, and its discovery identifies a fossil locality warranting thorough future exploration.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shelly fossils from the lower Cambrian White Point Conglomerate, Kangaroo Island, South Australia
Autorzy:
Betts, M.J.
Claybourn, T.M.
Brock, G.A.
Jago, J.B.
Skovsted, C.B.
Paterson, J.R.
Powiązania:
https://bibliotekanauki.pl/articles/22489.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The lower Cambrian (Series 2) White Point Conglomerate (WPC) on Kangaroo Island, South Australia contains exotic clasts representing a diverse array of lithologies, including metamorphics, chert, sandstone, and abundant carbonates, notably archaeocyath-rich bioclastic limestone. Acetic acid digestion of the WPC bioclastic limestone clasts reveals a diverse shelly fauna. This assemblage includes abundant organophosphatic brachiopods such as Cordatia erinae Brock and Claybourn gen. et sp. nov., Curdus pararaensis, Eodicellomus elkaniformiis, Eohadrotreta sp. cf. E. zhenbaensis, Eoobolus sp., Kyrshabaktella davidii, and Schizopholis yorkensis. Additional shelly taxa include the solenopleurid trilobite Trachoparia? sp., the tommotiids Dailyatia odyssei, Dailyatia decobruta Betts sp. nov., Kelanella sp., and Lapworthella fasciculata, spines of the bradoriid arthropod Mongolitubulus squamifer, and several problematica, such as Stoibostrombus crenulatus and a variety of tubular forms. The upper age limit for the WPC is constrained by biostratigraphic data from the overlying Marsden Sandstone and Emu Bay Shale, which are no younger than the Pararaia janeae Trilobite Zone (Cambrian Series 2, Stage 4). The shelly fossil assemblage from the WPC limestone clasts indicates an upper Dailyatia odyssei Zone (= Pararaia tatei to lower P. janeae trilobite zones), equivalent to the Atdabanian–early Botoman of the Siberian scheme. This contrasts with the previously suggested late Botoman age for the limestone clasts, based on the diverse archaeocyath assemblage. The minor age difference between the WPC and its fossiliferous limestone clasts suggests relatively rapid reworking of biohermal buildups during tectonically-active phases of deposition in the Stansbury Basin.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics
Autorzy:
Claybourn, T.M.
Skovsted, C.B.
Betts, M.J.
Holmer, L.E.
Bassett-Butt, L.
Brock, G.A.
Powiązania:
https://bibliotekanauki.pl/articles/2082288.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Tommotiida
Dailyatia
biostratigraphy
palaeobiogeography
Cambrian
Central Transantarctic Mountains
Opis:
Cambrian Series 2 shelly fossils from thick carbonate successions in East Antarctica have received limited systematic treatment through the 20th century. Described here are the East Antarctic camenellan tommotiids from the Shackleton Limestone in the Central Transantarctic Mountains and the Schneider Hills limestone in the Argentina Range. This material comes from both newly sampled collections and incompletely described material from older collections. The assemblage supports correlation to the Dailyatia odyssei Zone and Pararaia janeae Trilobite Zone of South Australia, with the newly examined specimens of Dailyatia decobruta from the Shackleton Limestone providing direct correlation to the Mernmerna Formation of the Ikara-Flinders Ranges and White Point Conglomerate of Kangaroo Island. These East Antarctic assemblages include five species referred to Dailyatia, in addition to an undetermined kennardiid species and fragments of the problematic Shetlandia multiplicata. The results further corroborate the notion that fossiliferous carbonate clasts found on King George Island were sourced from the same carbonate shelf as the Shackleton Limestone, with the taxon S. multiplicata found in both units. The Schneider Hills limestone in the Argentina Range has yielded sclerites of Dailyatia icari sp. nov., currently only known from this location.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 1; 207-229
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The oldest brachiopods from the lower Cambrian of South Australia
Autorzy:
Topper, T.P.
Holmer, L.E.
Skovsted, C.B.
Brock, G.A.
Balthasar, U.
Larsson, C.M.
Stolk, S.P.
Harper, D.A.T.
Powiązania:
https://bibliotekanauki.pl/articles/22055.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopod
Cambrian
South Australia
Brachiopoda
Tommotiida
Paterinida
Askepasma
microstructure
morphology
shell
Arrowie Basin
Lower Cambrian
Australia
paleontology
Opis:
The morphology and organophosphatic shell structure of the paterinate brachiopod Askepasma is documented using new and previously collected specimens from the lower Cambrian of South Australia. Lack of adequately preserved material has seen the majority of paterinate specimens previously reported from South Australia referred to the genus Askepasma and treated under open nomenclature. Large collections of paterinates from the lower Cambrian Wilkawillina, Ajax, and Wirrapowie limestones in the Arrowie Basin, South Australia have prompted redescription of the type species Askepasma toddense and the erection of a new species, Askepasma saproconcha sp. nov. Askepasma saproconcha sp. nov. currently represents the oldest known brachiopod from the lower Cambrian successions in South Australia with a FAD in pre−trilo− bitic (Terreneuvian, Cambrian Stage 2, lower Atdabanian) strata in the basal part of the Wilkawillina and Wirrapowie limestones. Askepasma toddense predominantly occurs in Abadiella huoi Zone equivalent strata (Unnamed Cambrian Se− ries 2, Stage 3, middle–upper Atdabanian) in the upper part of the lower Wilkawillina, Wirrapowie, and Ajax limestones. The shell microstructure of Askepasma suggests a proximal stem group position within the Brachiopoda and similarities with tommotiid taxa provides further evidence that the ancestry of crown group brachiopods is firmly entrenched within the Tommotiida.
Źródło:
Acta Palaeontologica Polonica; 2013, 58, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stagodontid marsupials from the Late Cretaceous of Canada and their systematic and functional implications
Autorzy:
Fox, R C
Naylor, B.G.
Powiązania:
https://bibliotekanauki.pl/articles/23125.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Canada
Cretaceous
Late Cretaceous
Stagodontidae
Mammalia
stagodontid mursupial
Alberta
Marsupialia
paleontology
Opis:
Previously undescribed specimens of stagodontid marsupials from Late Cretaceous deposits in Alberta, Canada, reveal new information concerning the upper dentition of Eodelphisspp. and the lower dentition of Didelphodon coyi. Additionally, an incomplete upper dentition of D. coyi from the Scollard Formation extends the range of this species into the Lancian, co−eval with D. vorax and D. padanicus. Stagodontids are in accord with other North American Late Cretaceous marsupials for which the appropriate parts are known in lacking diastemata between the canines and the molars while possessing well−developed palatal vacuities, implying that these morphologies characterized ancestral marsupials. If so, the diastema between P1 and P2 in the Asian middle Early Cretaceous “metatherian” Sinodelphys szalayi is convergent on that in Cenozoic didelphids, and the absence of palatal vacuities in South American Paleogene and Neogene borhyaenids is derived, representing a paedomorphic truncation of development. Claims that the Asian Late Cretaceous “metatherian” Deltatheridium pretrituberculare had a marsupial−like dental replacement pattern are tautological, deduced from an a priori acceptance of a marsupial model of replacement to the exclusion of other, no less realistic, alternatives. The new specimens of Didelphodon coyi demonstrate that upper and lower premolars occluded broadly, implying that the inflated lingual lobes characteristic of Didelphodon premolars evolved primarily as a crushing mechanism, not for passive protection of the gums. Recent speculations that stagodontids were aquatic are not based on credible morphologic or taphonomic evidence and are dismissed, as is speculation that the Judithian species of Eodelphis are sexual morphs of a single species. Current knowledge of Didelphodon compels correction of numerous errors concerning its morphology as presented in recent analyses of marsupial relationships.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Soft-tissue attachments in orthocerid and bactritid cephalopods from the Early and Middle Devonian of Germany and Morocco
Autorzy:
Kroger, B
Klug, C.
Mapes, R.
Powiązania:
https://bibliotekanauki.pl/articles/20326.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Cephalopoda
Germany
Orthocerida
Emsian
Morocco
Middle Devonian
soft tissue attachment
Early Devonian
Bactritida
muscle scar
Eifelian
Devonian
cephalopod
paleontology
Opis:
In the Early to Middle Devonian shale sequences of Germany and Morocco, pyritised and secondarily limonitised cephalopod remains are common. Details of the soft−tissue attachment structures are sometimes preserved on the internal moulds of the body chamber and phragmocone of these cephalopods. Some of the studied Orthocerida show a very faint annular elevation and a dorsal furrow. A few Bactritida show a distinctive annular elevation with two circular bands. The bands form a paired or threefold lobe at the dorsum of the shell. Morphological differences between Orthocerida and Bactritida suggest different soft part morphologies. A comparison of the attachment scars shows that the Bactritida are intermediate between the Orthocerida and ammonoids with regard to their muscle attachment scars. The shape of the muscle scars are interpreted as indication for a planktonic lifestyle in Orthocerida and a comparatively active, nektonic lifestyle in Bactritida and ammonoids. The new genus Acanthomichelinoceras is erected. Acanthomichelinoceras commutatum, Cycloceras sp., Bactrites gracile, Bactrites sp. A, Bactrites sp. B, and Bactrites sp. C are described.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The skull anatomy and cranial endocast of the pseudosuchid archosaur Prestosuchus chiniquensis from the Triassic of Brazil
Autorzy:
Mastrantonio, B.M.
Von Baczko, M.B.
Desojo, J.B.
Schultz, C.L.
Powiązania:
https://bibliotekanauki.pl/articles/22366.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Prestosuchus chiniquensis is the most famous “rauisuchian” described by Friedrich von Huene, eight decades ago, and several specimens have been assigned to this taxon since then. In the present contribution, we provide the first detailed description of a complete and very well preserved skull (including the braincase) assigned to Prestosuchus chiniquensis from the Dinodontosaurus Assemblage Zone of the Santa Maria Supersequence of southern Brazil. The detailed description of the skull of Prestosuchus chiniquensis, besides increasing the knowledge about this taxon, may help elucidate the taxonomic relationships of pseudosuchians even further, since most of the characters used in phylogenetic analyzes are cranial. The presence of the subnarial fenestra, a controvertial extra opening on the skull of “rauisuchians”, is thoroughly discussed considering the evidence provided by this new specimen. We consider that the small slit-opening between the premaxilla and the maxilla in Prestosuchus chiniquensis, can not safely be considered a true fenestra, but indicates more likely the existence of some degree of cranial kinesis between these elements which can result in different relative positions of the bones after definitive burial and fossilization, so that the size and shape of this opening is taphonomically controlled. Complementarily, the digital reconstruction of its cranial endocast was developed both from the observation of the preserved braincase and from CT scan images, which resulted in obtaining the first endocast known for a “rauisuchian”. The endocast of Prestosuchus chiniquensis exhibited some remarkable convergences with that of theropod dinosaurs, which could be a reflection of the similar niches they occupied, since “rauisuchians” were the top predators at the end of the Late Triassic, before the extinction of all non-crocodylomorph pseudosuchians.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revised classification and terminology of Palaeozoic stromatoporoids
Autorzy:
Stearn, C W
Webby, B D
Nestor, H
Stock, C W
Powiązania:
https://bibliotekanauki.pl/articles/23457.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Stromatoporida
Paleozoic
Labechiida
stromatoporoid
Stromatoporellida
morphology
taxonomy
carbonate skeleton
geographic distribution
stratigraphy
Clathrodictyida
classification
fossil
Syringostromatida
Amphiporida
catalogue number
terminology
Actinostromatida
paleontology
Opis:
Palaeozoic stromatoporoids comprise an extinct class of non-spiculate poriferans that are represented as fossils by their basal carbonate skeleton. A revised terminology for the description of these fossils is presented. Seven orders (Labechiida, Clathrodictyida, Actinostromatida, Stromatoporellida, Stromatoporida, Syringostromatida, Amphiporida) are recognized. The following is recorded for each genus: (1) type species, catalogue number and depository of the primary holotype; (2) synonyms and their type species; (3) diagnosis; (4) stratigraphic range; (5) estimate of the number of species assigned to the genus; (6) stratigraphic and geographic distribution of the genus. Problems in the definition and recognition of the genus are briefly discussed in annotations. One hundred and nine genera are considered valid, or doubtfully valid. Fifty three genera are placed in synonymy. An additional 14 genera are considered to be of uncertain placement in the classification.
Źródło:
Acta Palaeontologica Polonica; 1999, 44, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bashkirian rugose corals from the Carboniferous Mattson Formation in the Liard Basin, northwest Canada - stratigraphic and paleobiogeographic implications
Autorzy:
Fedorowski, J.
Bamber, E.W.
Richards, B.C.
Powiązania:
https://bibliotekanauki.pl/articles/20117.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Colonies of the rugose corals Nemistium liardense sp. nov. and Heritschioides simplex sp. nov. were collected from limestone in the upper member of the Mattson Formation in the Liard Range in the Northwest Territories and are the only known identifiable coral species from the Mattson Fm. The Mattson Fm., deposited in the Liard Basin west of the syndepositional Bovie reverse fault, comprises sandstone with subordinate shale and carbonates deposited during several delta cycles. The close morphological similarity and identical mode of offsetting in N. liardense colonies from the Mattson Fm. and the allochthonous Stikine Terrane of British Columbia indicate they belong in the same species. This and the morphological similarity between H. simplex and the late Serpukhovian to early Bashkirian H. columbicum allow assignment of the coral-bearing part of the upper Mattson Fm. to Bashkirian Foraminiferal Biozone 20. Widespread occurrence of the genus Nemistium confirms open communication between the Liard Basin region and the western European and northern African seas.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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