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Megasecoptera: morphology and taxonomy of newly discovered specimens from Upper Carboniferous of northern China (Insecta: Palaeodictyopteroida)
Pecharová, Martina ; Prokop, Jakub (advisor) ; Godunko, Roman (referee)
The extinct insect group of Palaeodictyopteroida (Insecta: Palaeoptera) comprised mainly phytophagous species and occurred from Upper Carboniferous to Upper Permian. Megasecoptera is one of several orders of belonging to this group. Although, the order Megasecoptera comprised over 20 described families, morphology of some body structures are insufficiently studied. The present thesis deals with evaluation of new material comprising the extensive set of 76 fossil insect specimens from the Upper Carboniferous (Bashkirian) of northern China. The fossils having excellent state of preservation of the wings and other body structures provide new insights concerning the external morphology of Megasecoptera. All studied specimens were attributed based on wing venation pattern into two known megasecopteran genera within families Brodiopteridae and Sphecopteridae. The aim of the present thesis is examine the morphology and variability of wing venation of two newly proposed species Brodioptera sp. n. and Cyclocelis sp. n. from site in northern China. In addition the following methods of geometric morphometrics based on landmarks were used for comparison of venational characters: a comparison of centroid size, procrustes analysis, principal component analysis and thin plate spline. Variability of wing venation...
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Gigantism of Paleozoic insects and other arthropods
Pecharová, Martina ; Prokop, Jakub (advisor) ; Knor, Stanislav (referee)
Gigantism of insects and other arthropods was rather common in Late Paleozoic. Hypothesis of the oxygen limitation is one the probable explanations caused the phenomenon. Carboniferous insect gigantism was probably directly caused by the higher level of atmospheric oxygen due to direct effectiveness on the tracheal system. Therefore the possibility to grow to large sizes is clearly dependent on the amount of available oxygen. Another fact supporting the hypothesis is the extinction or the change of the giant insect forms at the end of the Permian, when the level of atmospheric oxygen suddenly decreased. This thesis also describes the ecological relationships of the Late Paleozoic arthropods, which is clearly connected to the evolution of giant forms. Gigantism during this period was thus developed by the interplay of several factors related to the global elements cycles. Another part covers major groups and representatives of Palaeozoic gigantic insects and other arthropods. The final part is devoted to describing the physiological experiments related to this topic.
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Morphology and evolution of selected groups of Palaeodictyopterida (Insecta: Palaeoptera)
Pecharová, Martina ; Prokop, Jakub (advisor) ; Hodunko, Roman (referee) ; Sroka, Pavel (referee)
Palaeodictyopterida is remarkable insect superorder, which formed a significant part of the diversity of upper Palaeozoic insects, but disappeared by the end of the Permian. The main synapomorphy of the superorder is the piercing-sucking mouthparts in the form of a rostrum consisting of five styles. This rostrum was probably used to pierce on plant tissue and for the juice sucking. The same type of mouthparts shared by adults was present also in larvae of Palaeodictyopterida. The external copulatory organs of the superorder members was also showed some morphological interests. The male genitalia consist of a pair of gonostyli and two penial lobes, similarly to the genitalia of recent Ephemeroptera. The female genitalia of Palaeodictyopterida are developed in a form of the ovipositor that can be compared with the endophytic ovipositor of some recent Odonata. This morphological features support placement of Palaeodictyopterida as sister group of Odonatoptera + Panephemeroptera. The main aim of the work was to describe new representatives of the order Megasecoptera, the second largest group of Palaeodictyopterida. Wing venation of Megasecoptera exhibits a reduction of the longitudinal and transverse veins in comparison with the order Palaeodictyoptera. Other body structures were examined mainly in the...
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Morphology and evolution of selected groups of Palaeodictyopterida (Insecta: Palaeoptera)
Pecharová, Martina ; Prokop, Jakub (advisor) ; Hodunko, Roman (referee) ; Sroka, Pavel (referee)
Palaeodictyopterida is remarkable insect superorder, which formed a significant part of the diversity of upper Palaeozoic insects, but disappeared by the end of the Permian. The main synapomorphy of the superorder is the piercing-sucking mouthparts in the form of a rostrum consisting of five styles. This rostrum was probably used to pierce on plant tissue and for the juice sucking. The same type of mouthparts shared by adults was present also in larvae of Palaeodictyopterida. The external copulatory organs of the superorder members was also showed some morphological interests. The male genitalia consist of a pair of gonostyli and two penial lobes, similarly to the genitalia of recent Ephemeroptera. The female genitalia of Palaeodictyopterida are developed in a form of the ovipositor that can be compared with the endophytic ovipositor of some recent Odonata. This morphological features support placement of Palaeodictyopterida as sister group of Odonatoptera + Panephemeroptera. The main aim of the work was to describe new representatives of the order Megasecoptera, the second largest group of Palaeodictyopterida. Wing venation of Megasecoptera exhibits a reduction of the longitudinal and transverse veins in comparison with the order Palaeodictyoptera. Other body structures were examined mainly in the...
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Megasecoptera: morphology and taxonomy of newly discovered specimens from Upper Carboniferous of northern China (Insecta: Palaeodictyopteroida)
Pecharová, Martina ; Prokop, Jakub (advisor) ; Godunko, Roman (referee)
The extinct insect group of Palaeodictyopteroida (Insecta: Palaeoptera) comprised mainly phytophagous species and occurred from Upper Carboniferous to Upper Permian. Megasecoptera is one of several orders of belonging to this group. Although, the order Megasecoptera comprised over 20 described families, morphology of some body structures are insufficiently studied. The present thesis deals with evaluation of new material comprising the extensive set of 76 fossil insect specimens from the Upper Carboniferous (Bashkirian) of northern China. The fossils having excellent state of preservation of the wings and other body structures provide new insights concerning the external morphology of Megasecoptera. All studied specimens were attributed based on wing venation pattern into two known megasecopteran genera within families Brodiopteridae and Sphecopteridae. The aim of the present thesis is examine the morphology and variability of wing venation of two newly proposed species Brodioptera sp. n. and Cyclocelis sp. n. from site in northern China. In addition the following methods of geometric morphometrics based on landmarks were used for comparison of venational characters: a comparison of centroid size, procrustes analysis, principal component analysis and thin plate spline. Variability of wing venation...
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Gigantism of Paleozoic insects and other arthropods
Pecharová, Martina ; Prokop, Jakub (advisor) ; Knor, Stanislav (referee)
Gigantism of insects and other arthropods was rather common in Late Paleozoic. Hypothesis of the oxygen limitation is one the probable explanations caused the phenomenon. Carboniferous insect gigantism was probably directly caused by the higher level of atmospheric oxygen due to direct effectiveness on the tracheal system. Therefore the possibility to grow to large sizes is clearly dependent on the amount of available oxygen. Another fact supporting the hypothesis is the extinction or the change of the giant insect forms at the end of the Permian, when the level of atmospheric oxygen suddenly decreased. This thesis also describes the ecological relationships of the Late Paleozoic arthropods, which is clearly connected to the evolution of giant forms. Gigantism during this period was thus developed by the interplay of several factors related to the global elements cycles. Another part covers major groups and representatives of Palaeozoic gigantic insects and other arthropods. The final part is devoted to describing the physiological experiments related to this topic.
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