3 resultados para new taxa

em University of Queensland eSpace - Australia


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Research expeditions into remote areas to collect biological specimens provide vital information for understanding biodiversity. However, major expeditions to little-known areas are expensive and time consuming, time is short, and well-trained people are difficult to find. In addition, processing the collections and obtaining accurate identifications takes time and money. In order to get the maximum return for the investment, we need to determine the location of the collecting expeditions carefully. In this study we used environmental variables and information on existing collecting localities to help determine the sites of future expeditions. Results from other studies were used to aid in the selection of the environmental variables, including variables relating to temperature, rainfall, lithology and distance between sites. A survey gap analysis tool based on 'ED complementarity' was employed to select the sites that would most likely contribute the most new taxa. The tool does not evaluate how well collected a previously visited site survey site might be; however, collecting effort was estimated based on species accumulation curves. We used the number of collections and/or number of species at each collecting site to eliminate those we deemed poorly collected. Plants, birds, and insects from Guyana were examined using the survey gap analysis tool, and sites for future collecting expeditions were determined. The south-east section of Guyana had virtually no collecting information available. It has been inaccessible for many years for political reasons and as a result, eight of the first ten sites selected were in that area. In order to evaluate the remainder of the country, and because there are no immediate plans by the Government of Guyana to open that area to exploration, that section of the country was not included in the remainder of the study. The range of the ED complementarity values dropped sharply after the first ten sites were selected. For plants, the group for which we had the most records, areas selected included several localities in the Pakaraima Mountains, the border with the south-east, and one site in the north-west. For birds, a moderately collected group, the strongest need was in the north-west followed by the east. Insects had the smallest data set and the largest range of ED complementarity values; the results gave strong emphasis to the southern parts of the country, but most of the locations appeared to be equidistant from one another, most likely because of insufficient data. Results demonstrate that the use of a survey gap analysis tool designed to solve a locational problem using continuous environmental data can help maximize our resources for gathering new information on biodiversity. (c) 2005 The Linnean Society of London.

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A new species of Gyracanthides from the mid-Visean Ducabrook Formation of Middle Paddock site, near Springsure in the Drummond Basin, central Queensland, is based on isolated three-dimensionally preserved elements. The specimens comprise paired and unpaired spines and pectoral girdle elements, procoracoids and scapulocoracoids, and include growth series. The morphology, especially of the shoulder girdle bones and the form and tubercular ornamentation of the paired fin spines, is used to distinguish the new taxon. These characters also help differentiate the numerous described gyracanthid species. Aspects of palaeobiology including possible sexual dimorphism are explored. A hypothetical reconstruction of the fish is based on our interpretation of the articulation of isolated elements combined with examination of wear patterns on fin spines. Gyracanthides hawkinsi sp. nov. is compared with other Australian taxa as well as with gyracanthids from North America, Europe, Russia, Iran, Africa and Antarctica, some of which are tentatively reassigned here to the Gondwanan genus Gyracanthides.

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A fossil deposit excavated from the floor of Kids Cave, West Coast, South Island, New Zealand, is interpreted as having been primarily accumulated by New Zealand falcon Falco novaeseelandiae, with some contribution by Haast's eagle Harpagornis moorei. The fauna is rich: 3699 bones represented 41 bird species, two frog species, unspecified geckoes and skinks, and one bat species. Fossil deposition was mainly within the Last Glacial Maximum from about 22,000 cal yr bp to about 15,000 cal yr bp, with a marked change in sediment characteristics at the onset of the LGM's coldest period. Chronological control is given by three Uranium-series dates for a speleothem and radiocarbon AMS dating of four avian eggshell samples and one bone. The fauna is the first extensive predator accumulation of LGM age described from the West Coast of the South Island, and it indicates a palaeoenvironment of a mosaic of shrublands with forest patches. The onset of the coldest part of the LGM (Aurora 3 glacial advance, 19,500 - 19,000 cal yrs bp) saw marked climate cooling/drying affecting the site, but the avifauna indicates that although open-country taxa became more common in this period, some forest persisted nearby throughout the remainder of the LGM.