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Leandro Juen - One of the best experts on this subject based on the ideXlab platform.
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Assessing habitat quality on alpha and beta diversity of Odonata larvae (Insect) in logging areas in Amazon forest
Hydrobiologia, 2021Co-Authors: Thiago Pereira Mendes, Luciano Fogaça Assis Montag, Swanni T. Alvarado, Leandro JuenAbstract:The present study evaluated the effects of habitat quality on the alpha and beta diversity of odonate larvae under conditions of reduced impact and conventional logging. We hypothesized that the variation in the abiotic conditions found in areas of conventional logging would result in a greater loss of alpha and beta diversity in these areas in comparison with areas of reduced-impact logging and native forest. The study area was located in northeastern Pará state, in northern Brazil. We analyzed data from 10 control streams, located in areas of preserved native forest, 11 streams in forest harvested by reduced-impact logging, and nine streams in areas that had been logged conventionally. Environmental factors such as dissolved oxygen, woody debris, water temperature, sediments, and canopy cover were the principal predictors of the diversity of the Odonata. Our results showed that turnover was the principal component structuring beta diversity in the three areas (native forest, reduced impact and conventional logging). The results of the present study indicate that management initiatives based on reduced-impact logging techniques could be adopted to guarantee socio-economic benefits while minimizing the impacts of logging on local biodiversity.
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The Response of Neotropical Dragonflies (Insecta: Odonata) to Local and Regional Abiotic Factors in Small Streams of the Amazon.
Insects, 2019Co-Authors: José Max Barbosa Oliveira-junior, Karina Dias-silva, Maria Alexandra Teodósio, Leandro JuenAbstract:Since the relative role of local and regional abiotic factors on the Odonata diversity in rainforest streams is still poorly understood, we evaluated the effects of these factors on adult Odonata (Insecta) from preserved and altered streams in the Amazonian region. Adult Odonata were sampled in 98 streams in the Eastern Amazon, Para, Brazil. Six variables were used to measure local environmental factors: habitat integrity index; mean canopy over the channel; and four physical and chemical descriptors of the water. To measure regional environmental factors, six variables were also used: altitude gradient, three bioclimatic variables and two percentage forest variables. In partial redundancy analysis, both abiotic factors (local and regional) were important to explain the variation in the Odonata community. The Odonata community can be influenced by regional and local factors. The relationship between Odonata and the local (e.g., integrity, canopy cover, and physical and chemical descriptors of the water) and regional (e.g., bioclimatic and forest cover variables) environmental variables recorded in this study has important implications for the use of these organisms to monitor small streams of the Eastern Amazon. The scale at which habitat is measured is an important issue in community structuring studies considering the rapid environmental changes. It is of great importance to consider the different scales in studies assessing community structure, once an adequate habitat must meet the ecological needs of all stages of the life of the Odonata.
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Land use modifies Odonata diversity in streams of the Brazilian Cerrado
Journal of Insect Conservation, 2018Co-Authors: Lenize Batista Calvão, Leandro Juen, José Max Barbosa Oliveira-junior, Joana Darc Batista, Paulo Marco JúniorAbstract:The presence of riparian vegetation provides microclimatic regulation of stream conditions [e.g. luminosity (lux), air temperature (°C) and relative humidity (%)], which varies naturally throughout the day. These variables explain the diurnal behaviour patterns of ectotherms such as Odonata in natural areas. However, human land uses (e.g. pastures) modify the abiotic conditions of riparian environments, favouring the presence of disturbance-tolerant species. In this context, we assess relationships between riparian land use (control streams-natural areas and pasture), abiotic conditions habitat integrity index (in control and pastures streams), (air temperature, luminosity and humidity in control streams), and Odonata diversity (between pasture and control streams and throughout the time of day) in Brazilian savannah ( Cerrado ) streams. First, the control streams had higher habitat integrity index than pasture. Higher abundance and difference in composition of Odonata species were observed in streams surrounded by pasture relative to natural areas. The conversion of natural areas to pasture near streams was also accompanied by an increase in overall body size of Odonata species. Odonata species richness and abundance in natural areas varied throughout the day, but peaked around 12:00 h, coinciding with changes in air temperature and luminosity. Our study highlights that changes in the physical characteristics of streams through conversion of natural habitats to pasture will change environmental conditions and act as a filter on the distribution and persistence of Odonata species in Cerrado streams.
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Odonata insecta as a tool for the biomonitoring of environmental quality
Ecological Indicators, 2017Co-Authors: Thiago Barros Miguel, Leandro Juen, Jose Max Barbosa Oliveirajunior, Raphael LigeiroAbstract:Abstract Despite the fundamental dependence of human populations on water resources, a range of anthropogenic impacts, in particular the removal of riparian vegetation, threaten freshwater environments. One of the most effective means of evaluating the effects of anthropogenic disturbance in aquatic ecosystems is the use of bioindicators, and the insects of the order Odonata are among the most efficient indicators, due to their enormous sensitivity to environmental changes. In this context, the present study aimed to verify which parameters of the odonate community (species richness, abundance/biomass, composition, taxonomic diversity and taxonomic/phylogenetic distinctness) are most effective for the evaluation of the loss of environmental integrity. The study focused on 50 streams in the northeast of the Brazilian state of Para. The streams were sampled during the dry season, between June and August 2011. The physical characteristics of each stream were evaluated using a Habitat Integrity Index (HII). The species composition provided the best parameter for the evaluation of ecological integrity, providing a relatively accurate assessment at a lower mean research cost than other parameters. Taxonomic diversity and distinctness also provided relatively reliable results, contributed additional information on the evolutionary relationships among the odonate taxa, and also provided a low-cost approach. Deconstructing communities is necessary to detect impacts, considering the considerable variation in the environmental requirements of the different species. Overall, the parameter that best responded to gradients of disturbance was species composition, followed by diversity and taxonomic distinctness. Given these findings, odonate-based biomonitoring should focus on these parameters to guarantee the optimal detection and evaluation of habitat alterations.
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effect of vegetation removal for road building on richness and composition of Odonata communities in amazonia brazil
International Journal of Odonatology, 2013Co-Authors: Claudio Da Silva Monteiro, Sheyla Regina Marques Couceiro, Neusa Hamada, Leandro JuenAbstract:This study showed that the main impact on Odonata species of removal of riparian vegetation for road building was on community composition, since species richness remained unaltered. This result, most evident in damselflies, was probably driven by the entry of generalist species that replaced specialist species after the impact. We collected adult odonates in forested and deforested streams in the surroundings of Manaus, Amazonas, northern Brazil. We collected 380 specimens belonging to 32 odonate species. Erythrodiplax fusca and Argia sp. 1 could be used in biomonitoring programs, since they were significantly associated with deforested streams. Using odonate community composition and key species appears to be more efficient in biomonitoring programs than simply using species richness. Em nosso estudo mostramos que o principal impacto sobre as especies de Odonata causado pela retirada da vegetacao ciliar para a construcao de estradas e a modificacao na composicao da comunidade, uma vez que a riqueza de e...
Sebastian Büsse - One of the best experts on this subject based on the ideXlab platform.
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Resilin in the Flight Apparatus of Odonata (Insecta)-cap Tendons and Their Biomechanical Importance for Flight
Biology letters, 2019Co-Authors: Fabian Bäumler, Sebastian BüsseAbstract:In Odonata, a direct flight mechanism with specialized tendons evolved. One particular adaptation, the implementation of the rubber-like protein resilin in these cap tendons, might be of major importance. Although resilin was first described in one tendon of Odonata, to our knowledge no comprehensive study about the presence of resilin in the thorax exists yet. We investigated various species of Odonata, using µCT, dissection and fluorescence microscopy. Here we show a complete mapping of the Odonatan pterothorax, regarding the presence of tendons and their properties. Thus, 20-21 cap tendons in the pterothorax of Odonata show the presence of resilin. While performing outstanding and often-aggressive flight manoeuvres, resilin can provide shock absorption against mechanical damage from strong impacts. It may further improve the wear and fatigue resistance owing to resilin's damping behaviour. Additionally, resilin in tendons can absorb and return kinetic energy to restore muscles to their original shape after contracting and help in maintaining self-oscillation of the flight muscles. Here, the material distribution within the direct flight system of Odonata and the biomechanical importance and possible function of resilin are discussed. These results are an important step towards the understanding of the complex form-material-function interplay of the insect cuticle.
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The thorax morphology of Epiophlebia (Insecta: Odonata) nymphs – including remarks on ontogenesis and evolution
Scientific Reports, 2015Co-Authors: Sebastian Büsse, Benjamin Helmker, Thomas HornschemeyerAbstract:The species of Epiophlebia are unique among the recent Odonata in showing a mixture of morphological characters of dragonflies (Anisoptera) and damselflies (Zygoptera). The status of the four described extant species of Epiophlebia is disputable from a genetic as well as from a morphological point of view. Here we present an analysis of the thoracic musculature of different nymphal instars of Epiophlebia laidlawi and Epiophlebia superstes to elucidate their morphology and ontogenetic development. In total, 75 muscles have been identified in the thorax of Epiophlebia . This represents the highest number of thoracic muscles ever found in any odonate. It includes six muscles that are reported for the first time for Odonata and three of these are even new for Pterygota. In total, our results indicate that Epiophlebia has the most ancestral thoracic morphology among Odonata.
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the thorax morphology of epiophlebia insecta Odonata nymphs including remarks on ontogenesis and evolution
Scientific Reports, 2015Co-Authors: Sebastian Büsse, Benjamin Helmker, Thomas HornschemeyerAbstract:The species of Epiophlebia are unique among the recent Odonata in showing a mixture of morphological characters of dragonflies (Anisoptera) and damselflies (Zygoptera). The status of the four described extant species of Epiophlebia is disputable from a genetic as well as from a morphological point of view. Here we present an analysis of the thoracic musculature of different nymphal instars of Epiophlebia laidlawi and Epiophlebia superstes to elucidate their morphology and ontogenetic development. In total, 75 muscles have been identified in the thorax of Epiophlebia. This represents the highest number of thoracic muscles ever found in any odonate. It includes six muscles that are reported for the first time for Odonata, and three of these are even new for Pterygota. In total, our results indicate that Epiophlebia has the most ancestral thoracic morphology among Odonata.
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coding characters from different life stages for phylogenetic reconstruction a case study on dragonfly adults and larvae including a description of the larval head anatomy of epiophlebia superstes Odonata epiophlebiidae
Zoological Journal of the Linnean Society, 2015Co-Authors: Alexander Blanke, Sebastian Büsse, Ryuichiro MachidaAbstract:The exclusive use of characters coding for specific life stages may bias tree reconstruction. If characters from several life stages are coded, the type of coding becomes important. Here, we simulate the influence on tree reconstruction of morphological characters of Odonata larvae incorporated into a data matrix based on the adult body under different coding schemes. For testing purposes, our analysis is focused on a well-supported hypothesis: the relationships of the suborders Zygoptera, ‘Anisozygoptera’, and Anisoptera. We studied the cephalic morphology of Epiophlebia, a key taxon among Odonata, and compared it with representatives of Zygoptera and Anisoptera in order to complement the data matrix. Odonate larvae are characterized by a peculiar morphology, such as the specific head form, mouthpart configuration, ridge configuration, cephalic musculature, and leg and gill morphology. Four coding strategies were used to incorporate the larval data: artificial coding (AC), treating larvae as independent terminal taxa; non-multistate coding (NMC), preferring the adult life stage; multistate coding (MC); and coding larval and adult characters separately (SC) within the same taxon. As expected, larvae are ‘monophyletic’ in the AC strategy, but with anisopteran and zygopteran larvae as sister groups. Excluding larvae in the NMC approach leads to strong support for both monophyletic Odonata and Epiprocta, whereas MC erodes phylogenetic signal completely. This is an obvious result of the larval morphology leading to many multistate characters. SC results in the strongest support for Odonata, and Epiprocta receives the same support as with NMC. Our results show the deleterious effects of larval morphology on tree reconstruction when multistate coding is applied. Coding larval characters separately is still the best approach in a phylogenetic framework. © 2015 The Linnean Society of London
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The Thorax of Odonata (Insecta)
2013Co-Authors: Sebastian BüsseAbstract:The aim of my dissertation was to study the morphology and evolution of the thorax of damselflies and dragonflies (Odonata). One focus was the morphology of the thorax musculature and the homology between Odonata and a generalized Neoptera thorax as well as ground pattern of Pterygota (all winged insects). Furthermore, wing base skeletal element morphology was studied to extend and underscore the recent homology hypotheses. Beyond that, I examined the morphology, genetics and biogeography, and relating phylogeny of a very rare and enigmatic group of Odonata, Epiophlebia. Epiophlebia present a unique position within the Odonata. The group of Epiophlebia is closely related to all dragonflies but represents the only group of Odonata not belonging to dragonflies (Anisoptera) or damselflies (Zygoptera). The four known species of Epiophlebia are adapted to an extreme habitat in Asian mountain regions. They prefer cold and swiftflowing mountain streams at an altitude ranging from 1000 to 3500 meters above sea level (stenoecious lifestyle). The habitats of the Epiophlebia species are highly separated from each other on the Asian continent. Their respective range shows no overlap areas today, which typifies speciation via spatial isolation (separation). Results of genetic investigation of three of the four species‘ DNA segments (sequences) show surprising, extreme homogeneity. These results lead to a biogeographical scenario, which assumes a shared habitat of Epiophlebia during the Wurm ice age (approximately 20,000 years ago). When the warming phase started, Epiophlebia-populations were separated into distinct populations each located in a di!erent glacial refuge (simplified, cold withdraw areas). This short time frame could explain the genetic homogeneity observed. Nevertheless, the question of the species status of Epiophlebia remains: Is there only one species – Epiophlebia superstes – in four di!erent populations or are there four di!erent species? During a subsequent morphological study the species status at least of Epiophlebia laidlawi Tillard, 1921 could also be confirmed. Another study that draws directly on the genetic investigation of Epiophlebia, comprises a genetic sequence (S4-region of the 28s rRNA gene), which is suitable as a universal species identification tool for insects. Most insect specimens from all insect groups were successfully identified to species level with this tool. The investigation comprised 85 samples of 65 insect species, with at least one species per major clade of which the former represented a genus. We were able to demonstrate that our analysis system – which provides universal applicability and extended functionality – has advantages over the existing one (e.g. COI). The S4-method is applicable for degraded DNA that has, for example, been caused by aging, weathering or chemical influences. Investigation of the Odonata thorax comprised three studies. Two of the musculature and sclerites of adult Zygoptera flight apparatus and one of the entire nymphal Anisoptera thorax musculature. The aim was to understand and highlight peculiarities of the Odonatan thorax.To obtain the data and reach the best overall result possible, traditional morphological methods – such as dissecting and hand drawing – were combined with one of the latest morphological methods, which included computer tomography (SR!CT) aided by 3D reconstruction. By doing this, we discovered a total of 11 new, previously unknown muscles for Odonata. These morphological data were used to present the first complete homologization scheme of Odonata and neopterous insect thorax musculature. Furthermore, the homologies of the skeletal elements of the flight apparatus were confirmed and distinctly enhanced. This study also mark the first time muscle attachment points were discussed as important homology criteria. As a whole, these homology assessments allow unprecedented direct comparison between Odonata, which have a highly derived flight apparatus, and all other insects. Insights into the evolution and ground pattern of Odonata, even of all winged insects (Pterygota), were consequently gained. The homologies enable comparison and provide a complete new set of characters for subsequent analysis of the relationship (phylogenetic analysis) of Pterygota. A key, wing base sclerites‘ characteristic – the subalare – , points to the phylogenetic hypothesis of Paleoptera [Odonata+Ephemeroptera (mayflies)]. A generalized Odonata thorax that includes all recently known muscles will allow simplified work and access to the complex structure for future studies and will aid in furthering knowledge. This generalized thorax might be the initial point for a hypothetical ground pattern of pterygote insects and will allow insights into the development and evolution of the insect flight apparatus.
Michael J Samways - One of the best experts on this subject based on the ideXlab platform.
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Comparative effects of urban and agricultural land transformation on Odonata assemblages in a biodiversity hotspot
Basic and Applied Ecology, 2018Co-Authors: Gabriella J. Kietzka, James S. Pryke, Michael J SamwaysAbstract:Abstract Rivers of the Cape Floristic Region (CFR) biodiversity hotspot are threatened by land transformation. This region is a centre of endemism for many taxa, including Odonata. These insects are highly sensitive to changes in physical habitat structure, which makes them good bioindicators, and this led to the development of the Dragonfly Biotic Index (DBI). We investigated the effects of local agricultural and urban land transformations on Odonata species richness, assemblage composition and DBI scores in three CFR rivers. A total of 48 sites were selected and categorized as natural, agricultural or urban land use. Adult male Odonata and four environmental variables were recorded over two seasons. Land transformation significantly influenced Odonata assemblage composition but did not always significantly reduce species richness. Average vegetation height also affected Odonata assemblage composition and decreased species richness. Agricultural and urban sites had Odonata assemblages differing from those in the natural areas. Agricultural and urban local land use types reduced opportunities for some endemic species but provided for the persistence and establishment of widespread, generalist species, as indicated by great changes in DBI scores. Mitigating the adverse influences of land transformation through establishment of protected areas is essential for the conservation of rare taxa, particularly in an area with a high number of endemic species.
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dragonflies Odonata as indicators of biotope quality in the kruger national park south africa
Journal of Applied Ecology, 1996Co-Authors: Tanza E Clark, Michael J SamwaysAbstract:1. Monitoring programmes that assess ecosystem changes depend on indicator species or assemblages. Indicators should be sensitive and their response easily measured. This study assessed the suitability of adult male Odonata as indicators of biotope quality along the Sabie River in the Kruger National Park (KNP). 2. Odonate diversity was investigated at 25 sites along the Sabie River using univariate statistical procedures. The KNP supports 81 species, 59 recorded during this study (16 for the first time). 3. Sampling sites were classified by Two Way INdicator SPecies Analysis (TWINSPAN) and ordinated by DEtrended CORrespondence ANAlysis (DECORANA), based on the abundance of adult male Odonata. A predictive model relating Odonate species-groups to biotope variables, was formulated. 4. Classification led to the recognition of 10 ecologically meaningful biotope groups, each with an indicator species and a characteristic assemblage of associated species. 5. Multiple Discriminant Analysis (MDA) indicated that shade cover, permanency and flow rate could discriminate between biotope types defined by TWINSPAN. Variation in site membership between MDA and TWINSPAN suggests interaction between variables in determining species membership. 6. Biotope variables were incorporated into a model which predicted the membership of 82% of sites to the TWINSPAN groups; shade cover alone correctly predicted 44% of the sites. 7. The suitability of the Odonata as indicators of biotope quality, and its consequences for management are discussed.
Andrew C. Rehn - One of the best experts on this subject based on the ideXlab platform.
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Phylogenetic analysis of higher‐level relationships of Odonata
Systematic Entomology, 2003Co-Authors: Andrew C. RehnAbstract:Abstract. This is the most comprehensive analysis of higher-level relationships in Odonata conducted thus far. The analysis was based on a detailed study of the skeletal morphology and wing venation of adults, complemented with a few larval characters, resulting in 122 phylogenetically informative characters. Eighty-five genera from forty-five currently recognized families and subfamilies were examined. In most cases, several species were chosen to serve as exemplars for a given genus. The seven fossil outgroup taxa included were exemplar genera from five successively more distant odonatoid orders and suborders: Tarsophlebiidae (the closest sister group of Odonata, previously placed as a family within ‘Anisozygoptera’), Archizygoptera, Protanisoptera, ProtOdonata and Geroptera. Parsimony analysis of the data, in which characters were treated both under equal weights and implied weighting, produced cladograms that were highly congruent, and in spite of considerable homoplasy in the odonate data, many groupings in the most parsimonious cladograms were well supported in all analyses, as indicated by Bremer support. The analyses supported the monophyly of both Anisoptera and Zygoptera, contrary to the well known hypothesis of zygopteran paraphyly. Within Zygoptera, two large sister clades were indicated, one comprised of the classical (Selysian) Calopterygoidea, except that Amphipterygidae, which have traditionally been placed as a calopterygoid family, nested within the other large zygopteran clade comprised of Fraser's ‘Lestinoidea’ plus ‘Coenagrionoidea’ (both of which were shown to be paraphyletic as currently defined). Philoganga alone appeared as the sister group to the rest of the Zygoptera in unweighted cladograms, whereas Philoganga + Diphlebia comprised the sister group to the remaining Zygoptera in all weighted cladograms. ‘Anisozygoptera’ was confirmed as a paraphyletic assemblage that forms a ‘grade’ towards the true Anisoptera, with Epiophlebia as the most basal taxon. Within Anisoptera, Petaluridae appeared as the sister group to other dragonflies.
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phylogenetic analysis of higher level relationships of Odonata
Systematic Entomology, 2003Co-Authors: Andrew C. RehnAbstract:Abstract. This is the most comprehensive analysis of higher-level relationships in Odonata conducted thus far. The analysis was based on a detailed study of the skeletal morphology and wing venation of adults, complemented with a few larval characters, resulting in 122 phylogenetically informative characters. Eighty-five genera from forty-five currently recognized families and subfamilies were examined. In most cases, several species were chosen to serve as exemplars for a given genus. The seven fossil outgroup taxa included were exemplar genera from five successively more distant odonatoid orders and suborders: Tarsophlebiidae (the closest sister group of Odonata, previously placed as a family within ‘Anisozygoptera’), Archizygoptera, Protanisoptera, ProtOdonata and Geroptera. Parsimony analysis of the data, in which characters were treated both under equal weights and implied weighting, produced cladograms that were highly congruent, and in spite of considerable homoplasy in the odonate data, many groupings in the most parsimonious cladograms were well supported in all analyses, as indicated by Bremer support. The analyses supported the monophyly of both Anisoptera and Zygoptera, contrary to the well known hypothesis of zygopteran paraphyly. Within Zygoptera, two large sister clades were indicated, one comprised of the classical (Selysian) Calopterygoidea, except that Amphipterygidae, which have traditionally been placed as a calopterygoid family, nested within the other large zygopteran clade comprised of Fraser's ‘Lestinoidea’ plus ‘Coenagrionoidea’ (both of which were shown to be paraphyletic as currently defined). Philoganga alone appeared as the sister group to the rest of the Zygoptera in unweighted cladograms, whereas Philoganga + Diphlebia comprised the sister group to the remaining Zygoptera in all weighted cladograms. ‘Anisozygoptera’ was confirmed as a paraphyletic assemblage that forms a ‘grade’ towards the true Anisoptera, with Epiophlebia as the most basal taxon. Within Anisoptera, Petaluridae appeared as the sister group to other dragonflies.
Andre Nel - One of the best experts on this subject based on the ideXlab platform.
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The oldest ‘amphipterygid’ damselfly of tropical affinities in the Paleocene of Menat (Zygoptera: Eucaloptera)
Historical Biology, 2017Co-Authors: Romain Garrouste, Jean-marc Pouillon, Sonja Wedmann, Andre NelAbstract:The new damselfly genus and species Valerea multicellulata is described from the Paleocene of Menat (France), a Lagerstatte with many fossil insects, plants and vertebrates with high paleontological value. Aquatic insects are very scarce in this outcrop, this damselfly being the fourth described Odonata. Its closest modern relatives belong to the Amphipterygidae or the Devadattidae, families with very narrow tropical extant distributions. This new fossil allows us to confirm the tropical affinities of the Odonatan fauna of the Menat paleolake communities. It also shows that the amphipterygids were clearly more widespread during the Paleogene than today, probably in relation to the worldwide warm and equable climate in the Paleocene.
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new dragonflies from the lower cenomanian of france enlighten the timing of the Odonatan turnover at the early late cretaceous boundary
Cretaceous Research, 2015Co-Authors: Andre Nel, Gunther Fleck, Geraldine Garcia, Bernard Gomez, Patrice Ferchaud, Xavier ValentinAbstract:Three early Cenomanian Odonata are described from France (Jaunay-Clan locality, Vienne), i.e. the aeshnoid Galloliupanshania incompleta gen. et sp. nov. in the Liupanshaniidae, the libelluloid Gallophlebia magnifica gen. et sp. nov. in the new family Gallophlebiidae closely related to the Early Cretaceous Araripephlebiidae, and Gallostenophlebia incompleta gen. et sp. nov., as the youngest record of the clade Stenophlebioptera: Stenophlebiidae. Gallophlebia is a new case showing the high diversification of the libelluloid clade during the Cretaceous, while Gallostenophlebia corresponds to one of the last “survivors” of the Odonatan ancient lineages in relation to the faunistic turnover around the Early–Late Cretaceous boundary.
