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301.
Mayr G 《Die Naturwissenschaften》2007,94(8):681-685
Remains of fossil birds with numerous bony tubercles on the cervical vertebrae are reported from the Middle Eocene of Messel
in Germany and the Late Eocene of the Quercy fissure fillings in France. These structures, which are unknown from extant birds
and other vertebrates, were previously described for an avian skeleton from Messel but considered a singular feature of this
specimen. The new fossils are from a different species of uncertain phylogenetic affinities and show that tuberculated vertebrae
have a wider taxonomic, temporal, and geographic distribution. In contrast to previous assumptions, they are no ontogenetic
feature and arise from the vertebral surface. It is concluded that they are most likely of pathologic origin and the first
record of a Paleogene avian disease. Their regular and symmetrical arrangement over most of the external vertebral surface
indicates a systemic disorder caused by factors that do not affect extant birds, such as especially high-dosed phytohormones
or extinct pathogens. 相似文献
302.
We describe the earliest fossils of the enigmatic avian taxon Opisthocomiformes (hoatzins) from the Oligo-Miocene (22–24 mya)
of Brazil. The bones, a humerus, scapula and coracoid, closely resemble those of the extant hoatzin, Opisthocomus hoazin. The very similar osteology of the pectoral girdle in the new Brazilian fossil compared to the extant O. hoazin, in which it reflects peculiar feeding adaptations, may indicate that hoatzins had already evolved their highly specialized
feeding behavior by the mid-Cenozoic. We further show that Namibiavis senutae from the early Miocene of Namibia is another, previously misclassified representative of Opisthocomiformes, which documents
that the extant Neotropic distribution of hoatzins is relictual. Because of the weak flight capabilities of hoatzins, their
occurrence on both sides of the South Atlantic is of particular biogeographic interest. We detail that this distribution pattern
is best explained by dispersal from Africa to South America, and that Opisthocomiformes provide the first example of transatlantic
rafting among birds. 相似文献
303.
Gerald Schernewski Arunas Balciunas Dennis Gräwe Ulf Gräwe Kristina Klesse Marcus Schulz Sylvie Wesnigk David Fleet Mirco Haseler Nils Möllman Stefanie Werner 《Journal of Coastal Conservation》2018,22(1):5-25
Major objectives were to provide a comprehensive dataset on beach macro-litter for parts of the southern Baltic Sea and to analyse if the methodology is fully applicable and a suitable monitoring method in the Baltic. We carried out a regular macro litter beach monitoring (OSPAR methodology, 4 time a year) on 35 beaches along the German and Lithuanian Baltic coast over 2–5 years. Additional experiments addressed the subjectivity of the field surveys and spatio-temporal variability on different scales. We observed no seasonality of the data and a monthly compared to a 3-monthly sampling resulted in 3 times higher annual item numbers. Along the Lithuanian coast, the average number of items per survey varied between 138 and 340 and along the German Baltic coast between 7 and 404, with a median value of 47. All data showed a very high spatio-temporal variability. Using the Matrix Scoring Technique we assessed beach litter sources. With 50% tourism and recreation was the most important source. 3D–transport simulations helped to explain the minor role of shipping as a source and, compared to the North Sea, the low numbers of items on German Baltic beaches. Floating litter had a short duration time in the western Baltic Sea and offshore drift dominated. Further, the common regular beach cleanings reduced the potential for local litter accumulation and translocation. We suggest a monitoring system on 14 Baltic beaches in Germany and 2 in Lithuania and provide cost calculations. The analysis of macro-litter in cormorant nesting material and the search for beached dead animals did not show any result. We can conclude that the macro-litter beach monitoring method is less suitable for Baltic beaches and should only serve as a complementary method in combination with others. 相似文献
304.
Gerald Schernewski Caroline Bartel Nils Kobarg Donalda Karnauskaite 《Journal of Coastal Conservation》2018,22(1):157-167
We document and analyse the implementation process of a large combined coastal protection realignment and nature protection rewetting scheme, covering about 1000 ha at the German Baltic coast. The assessment reviews local planning documents, includes a media analysis, a tourist survey, stakeholder interviews and we provide criteria for measuring success, derived from the Systems Approach Framework (SAF) concept. The full process in the Geltinger Birk took over 25 years and was finished in 2013. The early years were characterised by strong local opposition, a polarization of the local society, misinformation and negative media coverage. Land purchase, the establishment of a local information centre with an environmental manager, improved public participation, a more pro-active media strategy and the readiness to accept compromises finally enabled a successful implementation. Today, a comprehensive tourism information and guidance system exists and the area became a popular tourist place. 80% of all visitors point out the outstanding nature experience and 87% are positive about the combined coastal protection and restoration measure. Parallel, major stakeholders changed their attitude and today are positive about the situation. However, the long timespan between initiation of the process and implementation of the measure, calls for a systematic, guided management approach, like the SAF. Especially, because climate change, sea level rise and increasing pressures on the coasts require a much faster implementation of adaptation measures in future. 相似文献
305.