Associated skeletons of a new middle Triassic "Rauisuchia" from Brazil

For more than 30 million years, in early Mesozoic Pangea, ??rauisuchian?? archosaurs were the apex predators in most terrestrial ecosystems, but their biology and evolutionary history remain poorly understood. We describe a new ??rauisuchian?? based on ten individuals found in a single locality from the Middle Triassic (Ladinian) Santa Maria Formation of southern Brazil. Nine articulated and associated skeletons were discovered, three of which have nearly complete skulls. Along with sedimentological and taphonomic data, this suggests that those highly successful predators exhibited some kind of intraspecific interaction. Other monotaxic assemblages of Triassic archosaurs are Late Triassic (Norian-Rhaetian) in age, approximately 10 million years younger than the material described here. Indeed, the studied assemblage may represent the earliest evidence of gregariousness among archosaurs, adding to our knowledge on the origin of a behavior pattern typical of extant taxa.     

Gas–particle partitioning of persistent organic pollutants in the Western Balkan countries affected by war conflicts

Background, aim, and scope  

Bombing and destruction of the industrial and military targets accompanied by complete or incomplete combustion during the war conflict and NATO operation in former Yugoslavia caused the emission of persistent organic pollutants into the atmosphere, water, and soil. A total of 129 ambient air samples from 24 background, urban, and industrial sites, including hot spots, were collected to assess a gas–particle partitioning behavior of various persistent organic pollutants.     

A new neosuchian with Asian affinities from the Jurassic of northeastern Brazil

Phylogenetic relationships near the origin of extant crocodylians are weakly supported, and this lack of resolution makes for poor estimates of taxonomic and morphological diversity. Previously known taxa are found throughout the Cretaceous in Laurasia and at a few sites from Brazil, Australia, and northern Africa. Here, we report Batrachomimus pastosbonensis gen. et sp. nov. from the Late Jurassic of northeastern Brazil, which is deeply nested within Neosuchia and associated to the Cretaceous Asian paralligatorids. The new taxon predates all other members of Paralligatoridae and its immediate sister group (including Eusuchia) by 30 million years. A nearly complete skull, osteoderms, and limb bones were recovered, and autapomorphies of B. pastosbonensis include a scalloped lateral margin of the rostrum in dorsal view, unsculpted alveolar margin at the caudalmost portion of the maxilla, blunt lateral prongs on the jugal at the base of the postorbital bar, hourglass shaped choanae, and pterygoid choanal septum extended between the palatal shelves of the palatines. The crocodyloid-like skull proportions and the slender, conical teeth suggest an amphibious and piscivorous life history to this 1 m long animal.

     

Sources and emission of greenhouse gases in Danube Delta lakes

Production of methane and carbon dioxide as well as methane concentrations in surface waters and emissions to the atmosphere were investigated in two flow-through lake complexes (Uzlina–Isac and Puiu–Rosu–Rosulet) in the Danube Delta during post-flood conditions in May and low water level in September 2006. Retained nutrients fuelled primary production and remineralisation of bioavailable organic matter. This led to an observable net release of methane, particularly in the lakes Uzlina, Puiu and Rosu in May. Input from the Danube River, from redbuds and benthic release contributed to CH₄ concentrations in surface waters. In addition to significant river input of CO₂, this trace gas was released via aerobic remineralisation within the water column and in top sediments. Emission patterns of CO₂ widely overlapped with those of CH₄. Generally, greenhouse gas emissions peaked in the lake complex adjacent to the Danube River in May due to strong winds and decreased with increasing hydrological distance from the Danube River. Intense remineralisation of organic matter in the Danube Delta lakes results in a net source of atmospheric greenhouse gases.     

Which compounds contribute most to elevated airborne exposure and corresponding health risks in the Western Balkans?

A majority of ongoing monitoring of persistent organic pollutants (POPs) is currently focused on chemicals emphasized in the Stockholm Convention. Quantitative detection of other substances (especially those with numerous anthropogenic sources such as polyaromatic hydrocarbons (PAHs)) is, however, also needed since their concentrations are usually several orders of magnitude higher. A goal of this study was to determine how various groups of compounds contribute to total human health risks at the variety of sampling sites in the region of Western Balkan. Distribution of the risks between the gas and particulate phases was also addressed. Results showed that inhalation exposure to organochlorine pesticides (OCPs) does not represent a significant risk to humans, while polychlorinated biphenyls (PCBs) re-volatilized to the atmosphere from contaminated soils and buildings can pose a problem. PCB evaporation from primary sources (currently used PCB-filled transformers or non-adequate storage facilities) generally resulted in much higher atmospheric concentrations than evaporation from the secondary sources (soils at the sites of war destructions). A majority of the human health risks at the urban sites were associated with PAHs. Between 83 and 94% of the cumulative risk at such sites was assigned to chemicals sorbed to particles, and out of it, PAHs were responsible for 99%.