A reassessment of the late jurassic turtle Eurysternum wagleri (Eucryptodira, Eurysternidae)

Eurysternum wagleri is one of the first named, yet most poorly understood turtles from the Late Jurassic of Europe. Over the years, many specimens have been referred to and many species synonymized with E. wagleri, but little consensus is apparent, and the taxonomy is therefore highly confusing. Based on the rare, only known illustration of the lost holotype and on the reassessment of select individuals, the species E. wagleri is recharacterized herein. Eurysternum wagleri is diagnosed by a deep pygal notch, a carapace with a pentagonal outline, a contribution of vertebral 5 to the posterior carapace margin, three cervical scales, very wide vertebral scales with a well-developed radiating pattern, well-developed costoperipheral fontanelles in medium-sized individuals, a plastron connected to the carapace by ligaments, gracile, peg-like bony projections of the hyo- and hypoplastra, and large, oval-to-quadrangular lateral plastral fontanelles. A lectotype is designated for Acichelys redenbacheri, and this taxon is interpreted as the junior subjective synonym of Eurysternum wagleri. All other, previously proposed synonymies are rejected, because they lack characters that would allow diagnosing them as E. wagleri

A review of the fossil record of turtles of the clade Thalassochelydia

The Late Jurassic (Oxfordian to Tithonian) fossil record of Europe and South America has yielded a particularly rich assemblage of aquatic pan-cryptodiran turtles that are herein tentatively hypothesized to form a monophyletic group named Thalassochelydia. Thalassochelydians were traditionally referred to three families, Eurysternidae, Plesiochelyidae, and Thalassemydidae, but the current understanding of phylogenetic relationships is insufficient to support the monophyly of either group. Given their pervasive usage in the literature, however, these three names are herein retained informally. Relationships with marine turtles from the Cretaceous have been suggested in the past, but these hypotheses still lack strong character support. Thalassochelydians are universally found in near-shore marine sediments and show adaptations to aquatic habitats, but isotopic evidence hints at a broad spectrum of specializations ranging from freshwater aquatic to fully marine. A taxonomic review of the group concludes that of 68 named taxa, 27 are nomina valida, 18 are nomina invalida, 18 are nomina dubia, and 5 nomina oblita

A review of the fossil record of nonbaenid turtles of the clade Paracryptodira

The fossil record of nonbaenid paracryptodires ranges from the Late Jurassic (Kimmeridgian) to the Paleocene of North America and Europe only. Earlier remains may be present as early as the Middle Jurassic (Bathonian). Only a single dispersal event is documented between the two continents after their breakup during the Cretaceous in the form of the appearance of the Compsemys lineage in the Paleocene of France. Nonbaenid paracryptodires were restricted to freshwater aquatic environments but display adaptations to diverse feeding strategies consistent with generalist, gape-and-suction, and hypercarnivorous feeding. Current phylogenies recognize two species-rich subclades within Paracryptodira, Baenidae and Pleurosternidae, which jointly form the clade Baenoidea. A taxonomic review of nonbaenid paracryptodires concludes that of 34 named taxa, 11 are nomina valida, 15 are nomina invalida, and 8 are nomina dubia

The 8 and 9 September 2002 flash flood event in France: a model intercomparison

Within the framework of the European Interreg IIIb Medocc program, the HYDROPTIMET project aims at the optimization of the hydrometeorological forecasting tools in the context of intense precipitation within complex topography. Therefore, some meteorological forecast models and hydrological models were tested on four Mediterranean flash-flood events. One of them occured in France where the South-eastern ridge of the French “Massif Central”, the Gard region, experienced a devastating flood on 8 and 9 September 2002. 24 people were killed during this event and the economic damage was estimated at 1.2 billion euros. To built the next generation of the hydrometeorological forecasting chain that will be able to capture such localized and fast events and the resulting discharges, the forecasted rain fields might be improved to be relevant for hydrological purposes. In such context, this paper presents the results of the evaluation methodology proposed by Yates et al. (2005) that highlights the relevant hydrological scales of a simulated rain field. Simulated rain fields of 7 meteorological model runs concerning with the French event are therefore evaluated for different accumulation times. The dynamics of these models are either based on non-hydrostatic or hydrostatic equation systems. Moreover, these models were run under different configurations (resolution, initial conditions). The classical score analysis and the areal evaluation of the simulated rain fields are then performed in order to put forward the main simulation characteristics that improve the quantitative precipitation forecast. The conclusions draw some recommendations on the value of the quantitative precipitation forecasts and way to use it for quantitative discharge forecasts within mountainous areas

Social and Hydrological Responses to Extreme Precipitations: An Interdisciplinary Strategy for Postflood Investigation

International audienceThis paper describes and illustrates a methodology to conduct postflood investigations based on interdisciplinary collaboration between social and physical scientists. The method, designed to explore the link between crisis behavioral response and hydrometeorological dynamics, aims at understanding the spatial and temporal capacities and constraints on human behaviors in fast-evolving hydrometeorological conditions. It builds on methods coming from both geosciences and transportations studies to complement existing post-flood field investigation methodology used by hydrometeorologists. The authors propose an interview framework, structured around a chronological guideline to allow people who experienced the flood firsthand to tell the stories of the circumstances in which their activities were affected during the flash flood. This paper applies the data collection method to the case of the 15 June 2010 flash flood event that killed 26 people in the Draguignan area (Var, France). As a first step, based on the collected narratives, an abductive approach allowed the identification of the possible factors influencing individual responses to flash floods. As a second step, behavioral responses were classified into categories of activities based on the respondents' narratives. Then, aspatial and temporal analysis of the sequences made of the categories of action to contextualize the set of coping responses with respect to local hydrometeorological conditions is proposed. During this event, the respondents mostly follow the pace of change in their local environmental conditions as the flash flood occurs, official flood anticipation being rather limited and based on a large-scale weather watch. Therefore, contextual factors appear as strongly influencing the individual's ability to cope with the event in such a situation

Climatology of banded precipitation over the contiguous United States

A climatology of banded-precipitation features over the contiguous United States from 2003–2014 is constructed. A band is defined as a precipitation feature with a major axis of 100 km or greater and a ratio of major axis length to minor axis length (hereafter, aspect ratio) of 3:1 or greater. By applying an automated feature-based detection algorithm to composite radar imagery, a database of 48,916,844 precipitation features is created, of which 7,213,505 (14.8%) are bands. This algorithm produces the first climatology of precipitation bands over the contiguous United States. Banded precipitation occurrence is broadly similar to total precipitation occurrence, with a maximum of 175 hours of banded precipitation annually over the Ohio River Valley. In the warm season, there is a strong diurnal signature associated with convective storm development for both precipitation feature area and total area covered by precipitation, but little diurnal signature in aspect ratio. A strong west-east gradient in both precipitation occurrence and banded precipitation occurrence exist, as areas west of the Rockies receive less frequent precipitation, which is much less likely to be banded. East of the Rockies, precipitation features are banded 30% of the time, versus 10–15% west of the Rockies. Areas downwind of the Great Lakes show prominent late autumn and winter maxima in banded precipitation associated with lake-effect snowbands. Local maxima of banded precipitation percentage occur in the Dakotas and east of the Colorado Rockies during winter. Although banded-precipitation features comprise only 14.8% of all precipitation features, they contribute 21.9% of the annual precipitation occurrence over the contiguous United States

A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles

Turtles (Testudinata) are a successful lineage of vertebrates with about 350 extant species that inhabit all major oceans and landmasses with tropical to temperate climates. The rich fossil record of turtles documents the adaptation of various sub- lineages to a broad range of habitat preferences, but a synthetic biogeographic model is still lacking for the group.Results: We herein describe a new species of fossil turtle from the Late Jurassic of Xinjiang, China, Sichuanchelys palatodentata sp. nov., that is highly unusual by plesiomorphically exhibiting palatal teeth. Phylogenetic analysis places the Late Jurassic Sichuanchelys palatodentata in a clade with the Late Cretaceous Mongolochelys efremovi outside crown group Testudines thereby establishing the prolonged presence of a previously unrecognized clade of turtles in Asia, herein named Sichuanchelyidae. In contrast to previous hypotheses, M. efremovi and Kallokibotion bajazidi are not found within Meiolaniformes, a clade that is here reinterpreted as being restricted to Gondwana.Conclusions: A revision of the global distribution of fossil and recent turtle reveals that the three primary lineages of derived, aquatic turtles, including the crown, Paracryptodira, Pan-Pleurodira, and Pan- Cryptodira can be traced back to the Middle Jurassic of Euramerica, Gondwana, and Asia, respectively, which resulted from the primary break up of Pangaea at that time. The two primary lineages of Pleurodira, Pan-Pelomedusoides and Pan-Chelidae, can similarly be traced back to the Cretaceous of northern and southern Gondwana, respectively, which were separated from one another by a large desert zone during that time. The primary divergence of crown turtles was therefore driven by vicariance to the primary freshwater aquatic habitat of these lineages. The temporally persistent lineages of basal turtles, Helochelydridae, Meiolaniformes, Sichuanchelyidae, can similarly be traced back to the Late Mesozoic of Euramerica, southern Gondwana, and Asia. Given the ambiguous phylogenetic relationships of these three lineages, it is unclear if their diversification was driven by vicariance as well, or if they display a vicariance-like pattern. The clean, primary signal apparent among early turtles is secondarily obliterated throughout the Late Cretaceous to Recent by extensive dispersal of continental turtles and by multiple invasions of marine habitats