Phylogeny of the higher Libelluloidea (Anisoptera: Odonata): An exploration of the most speciose superfamily of dragonflies

“…10A) that included all of the species tested at Zzyzx was constructed by combining two other trees (Saux et al, 2003;Ware et al, 2007) using a strict supertree algorithm (Sanderson et al, 1998). A second tree was generated that assumes that all libellulid species were equally related to each other in a monophyletic clade, while keeping the aeshnids separated (Fig.…”

Section: Statistical Analysesmentioning

confidence: 99%

Body size effects on the oxygen-sensitivity of dragonfly flight

Henry

Harrison

2014

Journal of Experimental Biology

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One hypothesis for the small size of insects relative to vertebrates, and the existence of giant fossil insects, is that atmospheric oxygen levels constrain insect body sizes because oxygen delivery is more challenging in larger insects. This study tested this hypothesis in dragonflies by measuring the oxygen sensitivity of flight metabolic rates and behavior during hovering for 11 species of dragonflies that ranged in mass by an order of magnitude. We measured flight times and flight metabolic rates in seven oxygen concentrations ranging from 30% to 2.5% to assess the sensitivity of their flight to atmospheric oxygen. We also assessed the oxygen sensitivity of flight in lowdensity air (nitrogen replaced with helium) in order to increase the metabolic demands of hovering flight. Lowered atmospheric densities did induce higher flight metabolic rates. Flight behavior was more sensitive to decreasing oxygen levels than flight metabolic rate. The oxygen sensitivity of flight metabolic rates and behaviors were not correlated with body size, indicating that larger insects are able to maintain an oxygen supply-to-demand balance even during flight.

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“…Bechly, 1996, Lohmann, 1996Bybee et al, 2008). Currently taxonomy suggests that there are eleven families in Anisoptera: Aeshnidae, Austropetaliidae, Gomphidae, Petaluridae, Cordulegastridae, Neopetaliidae, Chlorogomphidae, GSI (sensu Ware et al, 2007), Corduliidae, Macromiidae and Libellulidae, with Epiophlebiidae from Anisozygoptera considered by some to be an twelfth family of dragonflies. Although both Zygoptera and Anisoptera have roughly 3000 species, Zygoptera are divided into 21 families: Amphipterygidae, Calopterygidae, Chlorocyphidae, Coenagrionidae, Dicteriadidae, Euphaeidae, Hemiphlebiidae, Isostictidae, Lestidae, Lestoidedidae, Megapodagrionidae, Perilestidae, Philogangidae, Platycnemidae, Platystictidae, Polythoridae, Protoneuridae, Pseudolestidae, Pseudostigmatidae, Synlestidae, and Thaumatoneuridae.…”

Section: Species Diversity and Biogeographymentioning

confidence: 99%

“…Their analysis suggested that the biogeography of the endemic South African taxon Syncordulia was a result of a southwestern Cape origin, approximately 60 million years ago. Syncordulia is a member of the family Synthemistidae s.s. (called "GSI" by Ware et al, 2007; previously considered to be members of the Corduliidae s.l.). The other taxa in this family are mostly Australasian endemics.…”

Section: Anisoptera Phylogenymentioning

confidence: 99%