http://precedings.nature.com/tags/bird Recently posted documents tagged with 'bird' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://dx.doi.org/10.1038/npre.2008.2326.1 Recent coelurosaurian discoveries have greatly enriched our knowledge of the dinosaur-bird transition, but all reported taxa close to this transition are from relatively well-known coelurosaurian groups1-3. Here we report a new basal avialan, Epidexipteryx hui gen. et sp. nov., from the Middle-Late Jurassic of Inner Mongolia, China. This new species is characterized by an unexpected combination of characters seen in several different theropod groups, particularly the Oviraptorosauria. Phylogenetic analysis shows it to be the sister taxon to Epidendrosaurus4,5, forming a new clade at the base of Avialae6. Epidexipteryx also possesses two pairs of elongate ribbon-like tail feathers (ETFs), and its limbs lack contour feathers for flight. This finding shows that a member of the avialan lineage experimented with integumentary ornamentation as early as the Middle-Late Jurassic, and provides further evidence relating to this important aspect of the transition from non-avian theropods to birds. http://dx.doi.org/10.1038/npre.2008.2326.1 Wed, 24 Sep 2008 13:34:16 UTC A bizarre Jurassic maniraptoran from China with elongate ribbon-like feathers doi:10.1038/npre.2008.2326.1 2008-09-24 Fucheng Zhang Nature Precedings 2008-09-24T13:34:16Z Manuscript Developmental Biology Ecology Earth & Environment http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1492/version/1 The “silence” in Rachel Carson’s Silent Spring1 alludes to the demise of bird populations through reproductive problems and death resulting from exposure to the pesticides of that time, many of which are endocrine active. Endocrine disrupting chemicals (EDCs) are compounds which may interfere with the endocrine system, producing effects that may disrupt the physiologic function of hormones. Early research on EDC exposure in humans and wildlife has focused mainly on reproductive effects of estrogenic chemicals, however recent studies have revealed that effects of estrogenic as well as non-estrogen active chemicals are often more far reaching than the reproductive system, and even mild exposures experienced early in development may have detrimental effects that are maintained throughout adulthood. Here we show trenbolone acetate, an androgen active environmental contaminant used as a growth promoter for cattle, to cause a literal silence in Japanese quail (Coturnix japonica) chicks following a one time embryonic exposure. Vocalizations were not merely lessened; this is the first study to demonstrate an environmental contaminant to cause a complete abolishment of the ability to vocalize. Since many reasons for vocalization in birds are directly linked to survival of the individual and species, the potential for detrimental population effects is a grave possibility for many avian species that may encounter androgen active chemicals in the environment. Many androgen active EDCs are persistent and ubiquitous in distribution, thereforechances for exposure to these chemicals in birds may be high. We hope that powerful, yet subtle effects like the ones presented here will encourage further research with EDCs to expand beyond the traditional focus of reproductive effects of estrogenic chemicals. http://precedings.nature.com/documents/1492/version/1 Tue, 08 Jan 2008 19:01:39 UTC Silent Spring – the lost call hdl:10101/npre.2008.1492.1 2008-01-08 Michael J. Quinn Nature Precedings 2008-01-08T19:01:39Z Manuscript Developmental Biology Ecology Earth & Environment http://creativecommons.org/licenses/by/3.0/