Evidence for Carboniferous origin of the order Mantodea (Insecta: Dictyoptera) gained from forewing morphology

Homologies of the forewing venation pattern of the order Mantodea (Insecta: Dictyoptera) consistent with the accepted insect wing venation groundplan are proposed. A comparative morphological analysis was carried out based on a broad taxonomic sample of extant taxa. Besides macromorphological aspects, focus is given to the pattern of the tracheal system as a basis for establishing primary homologies. All extant praying mantids exhibit a composite stem composed of the posterior radius (RP) and the media (M) and most praying mantids exhibit a fusion of the anterior branch of RP + M with the anterior radius (RA). The wing venation of the species ?Mesoptilus dolloi, previously assigned to the polyphyletic fossil assemblage ‘Protorthoptera’, is re‐interpreted in the light of the new homology statement. Our interpretation suggests that it is a putative stem‐Mantodea, as are some other ‘protorthopterous’ taxa. This hypothesis implies that the total‐group Mantodea arose as soon as the Late Carboniferous, i.e. about 175 million years earlier than previously estimated. This analysis contributes to the view that most of the Late Carboniferous ‘Protorthoptera’ are stem‐representatives of the major polyneopteran clades (e.g. cockroaches, grasshoppers and crickets, rock‐crawlers), suggesting a survivorship of several main Pterygota lineages at the end‐Permian extinction event higher than previously expected. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 79–113.     

Functional relationships between plant feeding and prey feeding for a zoophytophagous bug

The consumption of plants by the zoophytophagous bug Macrolophus pygmaeus Rambur (Heteroptera : Miridae) in relation to the presence or absence of prey is monitored for 7 days. Tobacco plants enriched with ¹⁵N, a stable, nonradioactive isotope of nitrogen, are used for characterization. In the absence of prey, the relationship between time and ¹⁵N content (which equates to plant feeding) is linear, with a constant daily accumulation of ¹⁵N; however, if prey are available, the mathematical relationship becomes curvilinear. From day 1 to day 5, feeding on plants is independent of the consumption of prey. The rate of ¹⁵N accumulation decreases in the presence of prey after day 5, whereas the number of prey eaten remains unchanged.     

Thermoregulation during gravidity in the children's python (Antaresia childreni): a test of the preadaptation hypothesis for maternal thermophily in snakes

Pregnant squamate reptiles (i.e. lizards and snakes) often maintain higher and more stable body temperatures than their nonpregnant conspecifics, and this maternal thermophily enhances developmental rate and can lead to increased offspring quality. However, it is unclear when this behaviour evolved relative to the evolution of viviparity. A preadaptation hypothesis suggests that maternal thermophily was a preadaptation to viviparity. Oviparous squamates are unique among oviparous reptiles for generally retaining their eggs until the embryos achieve one fourth of their development. As a result, maternal thermophily by gravid squamates may provide the same thermoregulatory benefits, at least during early development, that have been associated with viviparity. Thus, the evolution of viviparity in squamates may reflect an expanded duration of a pre-existing maternal thermoregulatory behaviour. Despite its evolutionary relevance, thermoregulation during gravidity in oviparous squamates has not yet been explored in depth. In the present study, we examined whether gravidity was associated with thermoregulatory changes in the oviparous children's python, Antaresia childreni . First, we discovered that, compared to most snakes, A. childreni is at an advanced stage of embryonic development at oviposition. Second, using surgically implanted temperature loggers, we detected a significant influence of reproductive status on thermoregulation. Reproductive females maintained higher and less variable body temperatures than nonreproductive females and this difference was most pronounced during the last 3 weeks of gravidity. Overall, these results highlight the continuum between oviparity and viviparity in squamate reptiles and emphasize the importance of thermal control of early embryonic development independent of reproductive mode.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 499–508.     

Paraplacodus and the phylogeny of the Placodontia (Reptilia: Sauropterygia)

The skeletal anatomy of Paraplacodus broilii Peyer from the Grenzbitumen-horizon (Anisian-Ladinian boundary) of Monte San Giorgio (Switzerland) is described and compared with that of other placodonts. Paraplacodus is found to share a number of potential synapomorphies with Placodus which could potentially corroborate the monophyly of the Placodontoidea, but Placodus also shares an number of potential synapomorphies with the armored placodonts (Cyamodontoidea) which are absent in Paraplacodus. Parsimony analysis rejects the monophyly of the Placodontoidea, and places Paraplacodus at the root of the placodont tree, as the sister-taxon of all the other representatives of the clade. This correlates with a configuration of the temporal region of the skull that suggest the loss of the lower temporal arch in a diapsid skull. The loss of the lower temporal arch is therefore recognized as a sauropterygian synapomorphy, and might even be a lepidosauromorph synapomorphy.     

Reversal of eutrophication in Lake Geneva: evidence from the oligochaete communities

1. In Lake Geneva (Switzerland), total phosphorus concentrations have decreased from 90 mg m^?3 in 1979 to 55 mg m^?3 in 1990. 2. To assess the effects of this improvement, tubificid and lumbriculid communities were sampled in 1982 and in 1991 in the same areas, at a depth of 40 m. 3. Abundance of mesotrophic species (mostly Potamothrix vejdovskyi) and of eutrophic species (mostly Potamothrix hammoniensis) was lower in 1991 than in 1982; in contrast, oligotrophic species (mostly Peloscolex velutinus) were more abundant in 1991 than in 1982. 4. The changes recorded in 1991 were the same as those associated with a decrease of organic sedimentation. 5. Mean relative abundance of oligotrophic species increased from 17% in 1982 to 41% in 1991. According to these values, Lake Geneva was mesoeutrophic in 1982, but mesotrophic in 1991.     

Reptile phylogeny and the interrelationships of turtles

A comprehensive analysis of amniote interrelationships is presented in an attempt to test turtle interrelationships. The results refute earlier hypotheses that turtles are related to parareptiles, i.e. to procolophonids or pareiasaurs. Instead, turtles are shown to be the sister-group of Sauropterygia, the two clades being nested within Sauria as sister-group of Lepidosauriformes. This scenario is also supported by several developmental and soft tissue characters which are shown to be congruent with the current phylogeny. The analysis strongly supports a monophyletic Parareptilia, sister-group of a monophylctic Eurcptilia. The Diapsida, however, is paraphyletic unless it includes turtles and sauropterygians. Additionally, the position of turtles within Diapsida has major implications for the evolutionary history and/or significance of many characters, i.e. temporal fenestration.     

Theoretical habitat templets, species traits, and species richness: fish in the Upper Rhône River and its floodplain

• 1 Recent developments in ecological theory concerned with habitat templets, species assemblages, and life history traits were examined for the riverine fish communities of the Upper Rhône River, France, in the context of spatial–temporal habitat variability. Relationships among species traits, habitat utilization of species, the relationship between species traits and habitat utilization, and trends of species traits and species richness in the spatial–temporal variability of the habitat types were analysed.
• 2 Relationships among twelve species traits, and utilization of eight habitats were examined for twenty-five fish species using correspondence analysis; the relationship between species traits and habitat utilization was investigated by co-inertia analysis.
• 3 Positive relationships among species traits were observed for size, fecundity, and the number of reproductive cycles per individual. However, species were not well differentiated according to the habitat utilization, except for habitats rarely connected with the main channel (i.e. two types of oxbow lakes).
• 4 No significant relationship was found between species traits and habitat utilization, nor for either species traits or species richness when examined in the framework of spatial–temporal habitat variability. Only two species traits corresponded (with slight trends) to predictions in a river habitat templet: (i) the number of descendants per reproductive cycle increased along with temporal variability; and (ii) the number of reproductive cycles per individual was either low or high at low temporal variability and intermediate at elevated temporal variability.
• 5 The discrepancy between the predictions of the river habitat templet as well as of the patch dynamics concept and the results observed for the fish in the Upper Rhône was explained in terms of scale problems, the evolutionary ecology of the European fish fauna, and the history of the Rhône River.

     

Do geographic distribution,niche property and life form explain plants' vulnerability to global change?

We modelled the future distribution in 2050 of 975 endemic plant species in southern Africa distributed among seven life forms, including new methodological insights improving the accuracy and ecological realism of predictions of global changes studies by: (i) using only endemic species as a way to capture the full realized niche of species, (ii) considering the direct impact of human pressure on landscape and biodiversity jointly with climate, and (iii) taking species' migration into account. Our analysis shows important promises for predicting the impacts of climate change in conjunction with land transformation. We have shown that the endemic flora of Southern Africa on average decreases with 41% in species richness among habitats and with 39% on species distribution range for the most optimistic scenario. We also compared the patterns of species' sensitivity with global change across life forms, using ecological and geographic characteristics of species. We demonstrate here that species and life form vulnerability to global changes can be partly explained according to species' (i) geographical distribution along climatic and biogeographic gradients, like climate anomalies, (ii) niche breadth or (iii) proximity to barrier preventing migration. Our results confirm that the sensitivity of a given species to global environmental changes depends upon its geographical distribution and ecological proprieties, and makes it possible to estimate a priori its potential sensitivity to these changes.