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Lopez-Arbarello A.,Ludwig Maximilians University of Munich | Stockar R.,Museo Cantonale di Storia Naturale | Burgin T.,Naturmuseum
PLoS ONE | Year: 2014

The lagerstätten in the Monte San Giorgio have provided excellent fossils representing one of the most important windows to the marine life during the Triassic. Among these fossils, fishes are abundant and extraordinarily well preserved. Most of these fishes represent extinct lineages and were difficult to understand and classify during the early years after discovery. These difficulties usually led to a mixture of species under the same taxonomic name. This is the case of fishes referred to the genus Archaeosemionotus. The name bearing type of A. connectens, the type species of this genus, represents a basal halecomorph, but most other fishes referred to this genus represent basal ginglymodians. Therefore, we conducted this study to clarify the taxonomic status and phylogenetic relationships of A. connectens, which is a member of the family Furidae (Halecomorphi, Ionoscopiformes) representing the second cladistically supported evidence of ionoscopiforms in the Triassic and it is thus one of the two oldest reliable records of this group. Ionoscopiforms have a long stratigraphic range, though their fossil record is rather patchy. In our analysis, the sister taxon of Archaeosemionotus is Robustichthys from the Anisian of China, and they together form a clade with Furo, which is known from several localities ranging from the Early to the Late Jurassic. Other ionoscopiforms are so far known from the Kimmeridgian to the Albian and it is thus evident that recent efforts have concentrated on the later history of the group (Late Jurassic to Cretaceous). The phylogenetic relationships obtained for the Ionoscopiformes do not show a clear palaeobiogeographic pattern, but give important new insights into the origin, divergence date and early history of this clade. © 2014 López-Arbarello et al. Source


Giavi S.,Swiss Federal Institute of forest | Moretti M.,Swiss Federal Institute of forest | Bontadina F.,Urban Ecology and Wildlife Research | Bontadina F.,ETH Zurich | And 2 more authors.
PLoS ONE | Year: 2014

Migration is adaptive if survival benefits are larger than costs of residency. Many aspects of bat migration ecology such as migratory costs, stopover site use and fidelity are largely unknown. Since many migrating bats are endangered, such information is urgently needed to promote conservation. We selected the migrating Leisler's bat (Nyctalus leisleri) as model species and collected capture-recapture data in southern Switzerland year round during 6 years. We estimated seasonal survival and site fidelity with Cormack-Jolly-Seber models that accounted for the presence of transients fitted with Bayesian methods and assessed differences between sexes and seasons. Activity peaked in autumn and spring, whereas very few individuals were caught during summer. We hypothesize that the study site is a migratory stopover site used during fall and spring migration for most individuals, but there is also evidence for wintering. Additionally, we found strong clues for mating during fall. Summer survival that included two major migratory journeys was identical to winter survival in males and slightly higher in females, suggesting that the migratory journeys did not bear significant costs in terms of survival. Transience probability was in both seasons higher in males than in females. Our results suggest that, similarly to birds, Leisler's bat also use stopover sites during migration with high site fidelity. In contrast to most birds, the stopover site was also used for mating and migratory costs in terms of survival seemed to be low. Transients' analyses highlighted strong individual variation in site use which makes particularly challenging the study and modelling of their populations as well as their conservation. © 2014 Giavi et al. Source


Trivellone V.,Research Center Cadenazzo | Trivellone V.,Swiss Federal Institute of forest | Paltrinieri L.P.,Museo Cantonale di Storia Naturale | Jermini M.,Research Center Cadenazzo | Moretti M.,Swiss Federal Institute of forest
Insect Conservation and Diversity | Year: 2012

1. The effects of the current changes in traditional agricultural practices in the Alps on the biodiversity affecting ecosystem functions and services are little known. Vineyards are among the oldest anthropogenic environments of high cultural and natural value that shape the landscape of large areas in Central and Southern Europe. In several mountain regions of the Alps, vineyards are a valid alternative to the landscape homogenisation that has followed post-cultural land abandonment and agriculture intensification. Key unanswered questions remain regarding the relative contribution of several factors that influence biodiversity, and the level in management pressure with regard to taxonomic and functional diversity enhancement. 2. To answer these questions, we sampled leafhoppers (Auchenorrhyncha) as a model taxon using different standard techniques along 24 vine transects within 8 vineyard complexes in Southern Switzerland. Each transect included one vine row, vine canopy, its interrow and the adjacent slope; the latter two were permanently grass-covered. Data were analysed using a four-step approach. 3. Environment (five variables) and Management (four variables) accounted for most of the variance in the leafhopper assemblage. Pesticide use (insecticide and herbicide) and slope mowing are the most important management predictors of leafhopper species composition. 4. With increasing management pressure (i.e. pesticide and mowing), the number of indicator species and particularly the specialists (i.e. stenotopic and oligotopic species) decreases dramatically. 5. To promote taxonomic and functional complexity of communities in vineyard systems, we suggest low management pressure with moderate use of pesticide and a low intensity regime of slope mowing. © 2011 The Authors. Insect Conservation and Diversity © 2011 The Royal Entomological Society. Source


Wilson L.A.B.,University of Zurich | Furrer H.,University of Zurich | Stockar R.,Museo Cantonale di Storia Naturale | Sanchez-Villagra M.R.,University of Zurich
Palaeontology | Year: 2013

Despite an impressive radiation of more than 30 species in the wake of the end-Permian mass extinction, the taxonomic study of Saurichthys has suffered from a lack of universally diagnostic features and a lack of tested quantitative schemes that can be applied to analyse interspecific morphological differences. In this study, we provide an initial quantitative framework for morphological evolution in Saurichthys by focusing on a single bone, the opercle and exploring patterns of interspecific variability in shape using outline-based geometric morphometrics and linear measurements. For the six species examined, comprising 155 specimens and representatives from the Early, Middle and Late Triassic, our results indicate that interspecific shape differences largely reflect an anterior-posterior dimension decrease (= craniocaudal direction) as the dorso-ventral dimension remains similar. In contrast, intraspecific variability in shape is subtle and spread across the outline of the bone, such that counter-acting dimension differences (increase/decrease) were found to occur along a single margin at oblique axes in several species. Our quantitative scheme, which is widely applicable to other groups, provides a useful description of the broad modes of opercle shape change that may help as a starting framework from which to develop character states for opercle morphology in future study. © The Palaeontological Association. Source


Stockar R.,Museo Cantonale di Storia Naturale | Stockar R.,University of Lausanne | Renesto S.,University of Insubria
Swiss Journal of Geosciences | Year: 2011

A newly opened excavation in the Cassina beds of the Lower Meride Limestone (Monte San Giorgio UNESCO World Heritage List, Canton Ticino, Switzerland), has yielded a pachypleurosaurid (Reptilia: Sauropterygia) specimen which is identified as Neusticosaurus peyeri. The resulting co-occurrence of N. peyeri and N. edwardsii, the latter so far regarded as the sole species of the genus present in this horizon, challenges the hypothesis of a single anagenetic lineage in Neusticosaurus species from Monte San Giorgio. In addition, it leads to a reconsideration of the phylogenetic inferences about Neusticosaurus evolution in the Monte San Giorgio area. The stratigraphic distribution of the Neusticosaurus species in the Monte San Giorgio basin is updated on the basis of recent finds. © 2011 Swiss Geological Society. Source

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