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Roland R Melzer - One of the best experts on this subject based on the ideXlab platform.
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looking like limulus retinula axons and visual neuropils of the median and lateral eyes of scorpions
Frontiers in Zoology, 2013Co-Authors: Tobias Lehmann, Roland R MelzerAbstract:Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950.
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Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions
Frontiers in zoology, 2013Co-Authors: Tobias Lehmann, Roland R MelzerAbstract:Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950.
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Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions
Frontiers in Zoology, 2013Co-Authors: Tobias Lehmann, Roland R MelzerAbstract:Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950. Results Scorpion median eye retinula cells are linked to a first and a second visual neuropil, while some fibres additionally connect the median eyes with the arcuate body. The lateral eye retinula cells are linked to a first and a second visual neuropil as well, with the second neuropil being partly shared by projections from both eyes. Conclusions Comparing these results to previous studies on the visual systems of scorpions and other chelicerates, we found striking similarities to the innervation pattern in Limulus polyphemus for both median and lateral eyes. This supports from a visual system point of view at least a phylogenetically basal position of Scorpiones in Arachnida, or even a close relationship to Xiphosura. In addition, we propose a ground pattern for the central projections of chelicerate median eyes.
Tobias Lehmann - One of the best experts on this subject based on the ideXlab platform.
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looking like limulus retinula axons and visual neuropils of the median and lateral eyes of scorpions
Frontiers in Zoology, 2013Co-Authors: Tobias Lehmann, Roland R MelzerAbstract:Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950.
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Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions
Frontiers in zoology, 2013Co-Authors: Tobias Lehmann, Roland R MelzerAbstract:Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950.
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Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions
Frontiers in Zoology, 2013Co-Authors: Tobias Lehmann, Roland R MelzerAbstract:Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950. Results Scorpion median eye retinula cells are linked to a first and a second visual neuropil, while some fibres additionally connect the median eyes with the arcuate body. The lateral eye retinula cells are linked to a first and a second visual neuropil as well, with the second neuropil being partly shared by projections from both eyes. Conclusions Comparing these results to previous studies on the visual systems of scorpions and other chelicerates, we found striking similarities to the innervation pattern in Limulus polyphemus for both median and lateral eyes. This supports from a visual system point of view at least a phylogenetically basal position of Scorpiones in Arachnida, or even a close relationship to Xiphosura. In addition, we propose a ground pattern for the central projections of chelicerate median eyes.
Ieva Upeniece - One of the best experts on this subject based on the ideXlab platform.
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The unique fossil assemblage from the Lode Quarry (Upper Devonian, Latvia)
Fossil Record, 2001Co-Authors: Ieva UpenieceAbstract:Abstract. The unique fossil fauna from the Lode clay quarry, lower Frasnian, Latvia, includes a diverse ichthyofauna of at least 15 taxa of agnathans and gnathostomes, representing most of the major taxa of Devonian vertebrates. Six new fish taxa (five species and one genus) were discovered during the last ten years. Exceptionally well-preserved juvenile fishes (Asterolepis ornata, Lodeacanthus gaujicus) provide unique data on ontogenetic change. Diverse arthropods are recorded. Parasitic platyhelminth remains in juvenile fish bodies is their first discovery in the fossil record, and represents the oldest parasitic association ever found. A complete faunal and floral list for the Lode quarry is presented, with a detailed biostratigraphic section. Comparison of vertebrata taxa from the Gauja Regional Stage with similar of the Main Devonian Field, Scotland, Timan, Canada, and Germany is reviewed. Die einzigartige Lebensgemeinschaft von Lode reprasentiert eine diverse Fischfauna nahezu aller Hauptwirbeltiertaxa, die im Devon lebten. Sechs neue Fischtaxa (5 Arten und 1 Gattung) wurden in den letzten zehn Jahren in den Unter-Frasnium-Schichten der Ziegeleigrube von Lode in Lettland entdeckt. Insgesamt sind 15 identifizierte und unbestimmte Fisch- und Agnathen-Arten von dort bekannt. Besondere Beachtung wurde den ausergewohnlich gut erhaltenen Jugendformen von Asterolepis ornata und Lodeacanthus gaujicus und verschiedenen Invertebraten (Crustacea, Merostomata) gespendet, die in einer einzigen Linse fein verteilten Tones gefunden wurden. Reste parasitischer Platyhelminthen, die in Jungfischen auftreten, wurden hier zum ersten Mal als Fossilien entdeckt; sie reprasentieren die alteste bisher gefundene parasitische Gemeinschaft. Eine Liste der organischen Reste aus den Schichten der Ziegeleigrube Lode wird prasentiert. Ein detailliertes biostratigraphisches Profil wird beschrieben. Die Fischfaunen aus der Gauja Regional-Stufe werden mit denen vom Hauptdevonfeld Russlands, von Schottland, dem Timan, Kanadas und Deutschlands verglichen. doi: 10.1002/mmng.20010040108
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The unique fossil assemblage from the Lode Quarry (Upper Devonian, Latvia)
Fossil Record, 2001Co-Authors: Ieva UpenieceAbstract:The unique fossil fauna from the Lode clay quarry, lower Frasnian, Latvia, includes a diverse ichthyofauna of at least 15 taxa of agnathans and gnathostomes, representing most of the major taxa of Devonian vertebrates. Six new fish taxa (five species and one genus) were discovered during the last ten years. Exceptionally well-preserved juvenile fishes (<i>Asterolepis ornata, Lodeacanthus gaujicus</i>) provide unique data on ontogenetic change. Diverse arthropods are recorded. Parasitic platyhelminth remains in juvenile fish bodies is their first discovery in the fossil record, and represents the oldest parasitic association ever found. A complete faunal and floral list for the Lode quarry is presented, with a detailed biostratigraphic section. Comparison of vertebrata taxa from the Gauja Regional Stage with similar of the Main Devonian Field, Scotland, Timan, Canada, and Germany is reviewed. <br><br> Die einzigartige Lebensgemeinschaft von Lode repräsentiert eine diverse Fischfauna nahezu aller Hauptwirbeltiertaxa, die im Devon lebten. Sechs neue Fischtaxa (5 Arten und 1 Gattung) wurden in den letzten zehn Jahren in den Unter-Frasnium-Schichten der Ziegeleigrube von Lode in Lettland entdeckt. Insgesamt sind 15 identifizierte und unbestimmte Fisch- und Agnathen-Arten von dort bekannt. Besondere Beachtung wurde den außergewöhnlich gut erhaltenen Jugendformen von <i>Asterolepis ornata</i> und <i>Lodeacanthus gaujicus</i> und verschiedenen Invertebraten (Crustacea, Merostomata) gespendet, die in einer einzigen Linse fein verteilten Tones gefunden wurden. Reste parasitischer Platyhelminthen, die in Jungfischen auftreten, wurden hier zum ersten Mal als Fossilien entdeckt; sie repräsentieren die älteste bisher gefundene parasitische Gemeinschaft. Eine Liste der organischen Reste aus den Schichten der Ziegeleigrube Lode wird präsentiert. Ein detailliertes biostratigraphisches Profil wird beschrieben. Die Fischfaunen aus der Gauja Regional-Stufe werden mit denen vom Hauptdevonfeld Russlands, von Schottland, dem Timan, Kanadas und Deutschlands verglichen. <br.><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20010040108" target="_blank">10.1002/mmng.20010040108</a>
Stephan Schultka - One of the best experts on this subject based on the ideXlab platform.
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Bellinurus cf.truemanii (Merostomata) aus dem tiefen Oberkarbon (Namur B/C) von Fröndenberg (Nordrhein-Westfalen, Deutschland)
Paläontologische Zeitschrift, 1994Co-Authors: Stephan SchultkaAbstract:The xiphosurid Bellinurus cf. truemanii from the Namurian B/C of NW-Germany was probably living in large lakes in a transgressive coastal plain. Die Xiphosuren-Art Bellinurus cf. truemanii wird aus den Grenzschichten Namur B/C von Fröndenberg beschrieben. Die stratigraphische Verbreitung von Bellinurus und ihre mögliche Abhängigkeit vom Lebensraum der Gattung wird diskutiert. Als Lebensraum wird der Boden uferferner Bereiche in großflächigen Seen angenommen. Diese Süßwasserkörper wurden durch marine Ingressionen im Hinterland aufgestaut.
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bellinurus cf truemanii Merostomata aus dem tiefen oberkarbon namur b c von frondenberg nordrhein westfalen deutschland
Palaeontologische Zeitschrift, 1994Co-Authors: Stephan SchultkaAbstract:Die Xiphosuren-ArtBellinurus cf.truemanii wird aus den Grenzschichten Namur B/C von Frondenberg beschrieben. Die stratigraphische Verbreitung vonBellinurus und ihre mogliche Abhangigkeit vom Lebensraum der Gattung wird diskutiert. Als Lebensraum wird der Boden uferferner Bereiche in grosflachigen Seen angenommen. Diese Suswasserkorper wurden durch marine Ingressionen im Hinterland aufgestaut.
Hyun Sook Ko - One of the best experts on this subject based on the ideXlab platform.
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first record of tri spine horseshoe crab tachypleus tridentatus Merostomata xiphosurida limulidae from korean waters
Animal Systematics Evolution and Diversity, 2015Co-Authors: Kea Cheong Yang, Hyun Sook KoAbstract:A tri-spine horseshoe crab, Tachypleus tridentatus (Leach, 1819) was collected from a sandy beach of Udo Island of Jeju during the full moon tides in November 1997. Three spines on the posterior margin of the opisthosoma were characterized indicating that the specimen was T. tridentatus. This specimen was a female with the total length of 49.5 cm and prosoma width of 23.0 cm. Tachypleus tridentatus was the first record from Korean waters. A brief description and figures of the species were given. This finding indicates that Korea is included to the distribution range of the species.