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Sven Bradler - One of the best experts on this subject based on the ideXlab platform.
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is strudiella a Devonian insect
Nature, 2013Co-Authors: Thomas Hornschemeyer, Joachim T Haug, Olivier Bethoux, Rolf G Beutel, Sylvain Charbonnier, Thomas A Hegna, Markushermann Koch, Jes Rust, Sonja Wedmann, Sven BradlerAbstract:Arising from R. Garrouste et al. , 82–85 (2012)10.1038/nature11281 The origin of winged insects (Pterygota), one of the planet’s most diverse lineages of organisms, is assumed to lie in the Devonian, but as an extremely sparse fossil record impedes our understanding of their early diversification, any well-preserved insect fossil from this time would be particularly valuable1. Garrouste et al.2 described an arthropod from Upper Devonian freshwater sediments from the Strud locality in Belgium (∼360 million years ago) as an insect, Strudiella devonica. However, based on a thorough re-investigation of the specimen, we conclude that this interpretation is untenable. Hence we believe that, like several other Devonian arthropod remains3,4,5,6,7, Strudiella is not an insect, and utmost diligence should be taken in interpreting poorly preserved Devonian arthropods.
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Is Strudiella a Devonian insect?
Nature, 2013Co-Authors: Thomas Hornschemeyer, Joachim T Haug, Olivier Bethoux, Rolf G Beutel, Sylvain Charbonnier, Thomas A Hegna, Jes Rust, Sonja Wedmann, Markus Koch, Sven BradlerAbstract:Arising from R. Garrouste et al. Nature 488 , 82–85 (2012)10.1038/nature11281 The origin of winged insects (Pterygota), one of the planet’s most diverse lineages of organisms, is assumed to lie in the Devonian, but as an extremely sparse fossil record impedes our understanding of their early diversification, any well-preserved insect fossil from this time would be particularly valuable^ 1 . Garrouste et al. ^ 2 described an arthropod from Upper Devonian freshwater sediments from the Strud locality in Belgium (∼360 million years ago) as an insect, Strudiella devonica . However, based on a thorough re-investigation of the specimen, we conclude that this interpretation is untenable. Hence we believe that, like several other Devonian arthropod remains^ 3 , 4 , 5 , 6 , 7 , Strudiella is not an insect, and utmost diligence should be taken in interpreting poorly preserved Devonian arthropods.
Gavin C Young - One of the best experts on this subject based on the ideXlab platform.
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Paleobiogeography of Devonian vertebrates
The Paleontological Society Special Publications, 2017Co-Authors: Gavin C YoungAbstract:Five distinctive vertebrate faunas characterised by endemic taxa can be recognised for the Early Devonian (Euramerica, Siberia, Tuva, China, and East Gondwana). By Late Devonian time these faunal provinces are obscured by widespread taxa which also inhabited nonmarine aquatic environments, but indicate faunal communication between Gondwana, Euramerica and China. This marked change in pattern between the Early and Late Devonian may be attributed to intrinsic (evolutionary) or extrinsic causal factors. Dispersal capabilities of aquatic vertebrates may have increased during the initial gnathostome radiation of the Devonian, but a predominantly extrinsic cause (e.g. global change in geography or climate) is suggested by the similar pattern for marine invertebrate faunas of Early Devonian endemism and Late Devonian cosmopolitanism. Outstanding problems of Devonian vertebrate biogeography include faunal differentiation on the largest landmass of the time (Gondwana), and the nature of barriers and connections between East and West Gondwana, East Gondwana and South and North China, and West Gondwana and Euramerica. A vertebrate equivalent of the cool-water Malvinokaffric invertebrate faunal realm of the Siluro-Devonian is not clearly identified, but vertebrate data from southern Africa and south America are sparse.Wide latitudinal distributions for some Late Devonian vertebrate taxa appear anomalous, and could indicate either reduced global climatic gradients, or erroneous paleogeographic base maps. There are difficulties in formulating a hypothesis of global warming and/or major paleogeographic change in a way which clearly distinguishes basic from interpreted data. Three major subdisciplines (paleomagnetism, paleoclimatology, paleobiogeography) contribute to Paleozoic paleogeographic reconstructions. Their data tend to be organised and represented in different ways, but each relies on the same principle of concordance with a general pattern (Young 1990). Degree of consilience of a hypothesis based on one data set (the extent to which it explains patterns within an unrelated set of data) is a primary criterion for accepting or rejecting the hypothesis. Apparent polar wander path representation facilitates testing of paleomagnetic data against those paleoclimatic or paleobiogeographic data which provide evidence of paleolatitude. However, as well as the simple indication of paleolatitude, biogeographic and some other qualitative data sets provide more complex evidence concerning connections or barriers between regions, for which APWP representation is not appropriate. Cladistic analysis of hierarchically organised data sets (Young, 1986, 1987) provides a means of integrating qualitative paleobiogeographic, paleoclimatic, and paleogeographic data such that inconsistencies in the evidence are emphasised, and the hypothesis is exposed to falsification. These ideas are illustrated using Devonian examples.
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placoderms armored fish dominant vertebrates of the Devonian period
Annual Review of Earth and Planetary Sciences, 2010Co-Authors: Gavin C YoungAbstract:Placoderms, the most diverse group of Devonian fishes, were globally distributed in all habitable freshwater and marine environments, like teleost fishes in the modern fauna. Their known evolutionary history (Early Silurian–Late Devonian) spanned at least 70 million years. Known diversity (335 genera) will increase when diverse assemblages from new areas are described. Placoderms first occur in the Early Silurian of China, but their diversity remained low until their main evolutionary radiation in the Early Devonian, after which they became the dominant vertebrates of Devonian seas. Most current placoderm data are derived from the second half of the group's evolutionary history, and recent claims that they form a paraphyletic group are based on highly derived Late Devonian forms; 16 shared derived characters are proposed here to support placoderm monophyly. Interrelationships of seven placoderm orders are unresolved because Silurian forms from China are still poorly known. The relationship of placoderms t...
Vincent Pernegre - One of the best experts on this subject based on the ideXlab platform.
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Systematic Palaeontology (Vertebrate Palaeontology) / Paléontologie systématique First Devonian dipnoans (Vertebrata, Sarcopterygii) from Spitsbergen
2020Co-Authors: Gaël Clément, Vincent Dupret, Daniel Goujet, Vincent PernegreAbstract:AbstractFor the first time, dipnoan remains are described from the Devonian of Spitsbergen. According to the stratigraphy and theassociated vertebrate fauna, they are considered as Late Emsian–Early Eifelian in age. Unfortunately remains are too sketchy andnon-diagnostic to be referred or compared to a known Devonian dipnoan. This new material, determined as Dipnoi gen. et sp.indet., is nevertheless important in biostratigraphical and palaeobiogeographical points of view, since it is amongst the earliestdipnoan occurrences, and the first one in the Devonian of Spitsbergen. To citer this article: G. Clement et al., C. R. Palevol 5(2006).© 2006 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.ResumePremiere occurrence de dipneustes (Vertebres sarcopterygiens) dans le Devonien du Spitzberg. Des restes de dipneustesdu Devonien du Spitzberg sont decrits pour la premiere fois. D’apres la stratigraphie et la faune de vertebres associee a ces restes,ils sont consideres comme etant d’âge Emsien superieur a Eifelien inferieur. Les specimens sont malheureusement trop rares et peudiagnostiques pour pouvoir etre attribues ou meme compares aux autres dipneustes devoniens decrits. Ce nouveau materiel,determine comme Dipnoi gen. et sp. indet., est neanmoins important, du double point de vue biostratigraphique et paleobiogeo-graphique. En effet, ces specimens de dipneustes, parmi les plus anciens decouverts, sont les premiers a etre signales dans leDevonien du Spitzberg. Pour citer cet article : G. Clement et al., C. R. Palevol 5 (2006).© 2006 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
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systematic palaeontology vertebrate palaeontology paleontologie systematique first Devonian dipnoans vertebrata sarcopterygii from spitsbergen
2006Co-Authors: Gaël Clément, Vincent Dupret, Daniel Goujet, Vincent PernegreAbstract:AbstractFor the first time, dipnoan remains are described from the Devonian of Spitsbergen. According to the stratigraphy and theassociated vertebrate fauna, they are considered as Late Emsian–Early Eifelian in age. Unfortunately remains are too sketchy andnon-diagnostic to be referred or compared to a known Devonian dipnoan. This new material, determined as Dipnoi gen. et sp.indet., is nevertheless important in biostratigraphical and palaeobiogeographical points of view, since it is amongst the earliestdipnoan occurrences, and the first one in the Devonian of Spitsbergen. To citer this article: G. Clement et al., C. R. Palevol 5(2006).© 2006 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.ResumePremiere occurrence de dipneustes (Vertebres sarcopterygiens) dans le Devonien du Spitzberg. Des restes de dipneustesdu Devonien du Spitzberg sont decrits pour la premiere fois. D’apres la stratigraphie et la faune de vertebres associee a ces restes,ils sont consideres comme etant d’âge Emsien superieur a Eifelien inferieur. Les specimens sont malheureusement trop rares et peudiagnostiques pour pouvoir etre attribues ou meme compares aux autres dipneustes devoniens decrits. Ce nouveau materiel,determine comme Dipnoi gen. et sp. indet., est neanmoins important, du double point de vue biostratigraphique et paleobiogeo-graphique. En effet, ces specimens de dipneustes, parmi les plus anciens decouverts, sont les premiers a etre signales dans leDevonien du Spitzberg. Pour citer cet article : G. Clement et al., C. R. Palevol 5 (2006).© 2006 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
Wei Li - One of the best experts on this subject based on the ideXlab platform.
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timing of paleozoic amalgamation between the north china and south china blocks evidence from detrital zircon u pb ages
Tectonophysics, 2013Co-Authors: Yunpeng Dong, Franz Neubauer, Guowei Zhang, Yiguo Zhang, Xiaoning Zhang, Wei LiAbstract:Abstract LA-ICP-MS U–Pb ages of detrital zircons from clastics of the undated fore-arc sedimentary unit (FAS) along the Shangdan Suture and the Middle–Upper Devonian Liuling Group in the South Qinling belt are used to establish the maximum depositional age and provenance of these tectonic units which were deposited on both sides of the Shangdan suture zone between the North China Block (NCB) and South China Block (SCB). The new data and geological evidence show that the FAS was deposited in a fore-arc basin with an exclusive source of the clastics in the North Qinling Belt (NQB). The depositional age of FAS is limited by the youngest U–Pb 455 Ma-ages of detrital zircons from clastics and the intrusive age of 435 ± 7 Ma of mafic dykes between the Late Ordovician–Early Silurian, while the NCB was still separated from the SCB by the Shangdan Ocean. However, detrital zircon U–Pb ages from six samples of the Middle Devonian Liuling Group indicate sources in both NQB and SCB suggesting pre-Middle Devonian collision of NCB and SCB. All results indicate deposition of the FAS in a forearc setting upon an active continental margin during Late Ordovician–Early Silurian, while the Middle–Upper Devonian Liuling Group represents a marine foreland basin after closure of the Shangdan Ocean. Together with the unconformity between Middle Devonian and pre-Devonian strata, this reveals still evolving subduction and accretion on the southern side of the NQB during the Ordovician-Early Silurian, and the Early Devonian collision between the NCB and SCB.
Thomas Hornschemeyer - One of the best experts on this subject based on the ideXlab platform.
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is strudiella a Devonian insect
Nature, 2013Co-Authors: Thomas Hornschemeyer, Joachim T Haug, Olivier Bethoux, Rolf G Beutel, Sylvain Charbonnier, Thomas A Hegna, Markushermann Koch, Jes Rust, Sonja Wedmann, Sven BradlerAbstract:Arising from R. Garrouste et al. , 82–85 (2012)10.1038/nature11281 The origin of winged insects (Pterygota), one of the planet’s most diverse lineages of organisms, is assumed to lie in the Devonian, but as an extremely sparse fossil record impedes our understanding of their early diversification, any well-preserved insect fossil from this time would be particularly valuable1. Garrouste et al.2 described an arthropod from Upper Devonian freshwater sediments from the Strud locality in Belgium (∼360 million years ago) as an insect, Strudiella devonica. However, based on a thorough re-investigation of the specimen, we conclude that this interpretation is untenable. Hence we believe that, like several other Devonian arthropod remains3,4,5,6,7, Strudiella is not an insect, and utmost diligence should be taken in interpreting poorly preserved Devonian arthropods.
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Is Strudiella a Devonian insect?
Nature, 2013Co-Authors: Thomas Hornschemeyer, Joachim T Haug, Olivier Bethoux, Rolf G Beutel, Sylvain Charbonnier, Thomas A Hegna, Jes Rust, Sonja Wedmann, Markus Koch, Sven BradlerAbstract:Arising from R. Garrouste et al. Nature 488 , 82–85 (2012)10.1038/nature11281 The origin of winged insects (Pterygota), one of the planet’s most diverse lineages of organisms, is assumed to lie in the Devonian, but as an extremely sparse fossil record impedes our understanding of their early diversification, any well-preserved insect fossil from this time would be particularly valuable^ 1 . Garrouste et al. ^ 2 described an arthropod from Upper Devonian freshwater sediments from the Strud locality in Belgium (∼360 million years ago) as an insect, Strudiella devonica . However, based on a thorough re-investigation of the specimen, we conclude that this interpretation is untenable. Hence we believe that, like several other Devonian arthropod remains^ 3 , 4 , 5 , 6 , 7 , Strudiella is not an insect, and utmost diligence should be taken in interpreting poorly preserved Devonian arthropods.