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21.
A new genus Webbyites from the Lower and Middle Ordovician of Bohemia is described. Its planar, feather-like benthic colonies (or their parts) display possible hydrozoan affinites. Webbyites is interpreted as an inhabitant of the littoral and sublittoral environment, with high energy, oscillating to current zones.  相似文献   
22.
A new heterosporous fern species, Azolla boliviensis sp. nov., is described from latest Maastrichtian (latest Cretaceous) to Paleocene (earliest Palaeogene) terrestrial sediments of the Eslabón and Flora Formations, Subandean belt, Bolivia. The species is represented by dissociated but abundantly co-preserved megasporocarps, megaspores, microsporangia, massulae and microspores. The genus consistently characterizes warm-climate lacustrine settings. Fossil Azolla is first identified around the Early to mid-Cretaceous but the genus apparently underwent dramatic radiation during the Late Cretaceous. Abundant Azolla remains in Bolivia add to this portrait of rapid geographie dispersai and diversification near the close of the Cretaceous. The ranges of many Azolla species span the Cretaceous- Palaeogene boundary and the potential of Azolla to withstand altered environmental conditions, such as periodic frost damage, drought, and salinity change, and its ability to undergo rapid vegetative regeneration in association with nitrogen-fixing cyanobacterial symbionts, suggest that the survival of this group was favoured during the adverse conditions of the end-Cretaceous event.  相似文献   
23.
Editorial     
Stephen McLoughlin, Honorary Editor, Department of Paleobotany, Swedish Museum of Natural History, Box 50007, 104 05 Stockholm, Sweden.  相似文献   
24.
Over the past 18 years the results of archaeological field research in many parts of Australia have challenged the view of late Pleistocene archaeological unity and homogeneity. Debates are increasingly focused on issues of identifying regional behavioral variability and away from a normalization of Australia's prehistory. Prior notions of cultural transformations from simple (late Pleistocene) to complex (late Holocene) social behaviors, technological homogeneity, and the timing of colonization are being increasingly scrutinized. One such area that has become a spearhead of this challenge is Tasmania, which continues to demonstrate its ability to confront preconceptions about the nature of past human behaviors.  相似文献   
25.
Bone collagen stable nitrogen isotope values are reported for modern kangaroos (Macropus spp.) from eight field sites along a 1160 km south–north transect from temperate coastal to arid interior South Australia, in order to investigate δ15N tissue variability in relation to rainfall and relative humidity. Mean annual rainfall along the transect ranges from 775 mm at Mount Gambier in the southeastern coast to 176 mm at Innamincka in the arid northern interior, while 3pm relative humidity ranges from 73% at coastal Flinders Chase to 36% at Innamincka. In arid habitats (176–238 mm rainfall), the δ15N values of kangaroo bone collagen become more positive in relation to decreasing mean annual rainfall (r2 = 0.98), while there is only a weak correlation with relative humidity (r2 = 0.67). In contrast, in temperate and semi‐arid coastal habitats (350–775 mm), there is no correlation between kangaroo bone collagen δ15N values and rainfall (r2 = 0.0011) or between δ15N values and relative humidity (r2 = 0.0035). Thus, in South Australia, kangaroo bone collagen δ15N values do not show a simple linear correlation with either rainfall or relative humidity across all habitats. These results suggest that stable nitrogen isotope analyses of herbivore bones obtained from archaeological and palaeontological sites may provide a reliable proxy for past rainfall values in arid‐land ecosystems. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
26.
The development of the shell and patterns of reticulation in the middle Miocene ostracodes Hermanites glyphica and Quasibradleya are explored in relation to the development of macro-reticulation (primary) and micro-reticulation (secondary), and the effects of aggradation and degradation on surface morphology. Microreticulation is shown to be genetically controlled, not polymorphic or environmentally controlled, whereas aggradation and degradation are shown to vary continuously. Some relationships between ostracode morphology and intraspecific variation, environmentally-cued polymorphism and the phenomena of aggradation and degradation are discussed.  相似文献   
27.
Bioarchaeological analysis of the MDM site (8DA11) in Miami, Florida (ad 400–1200) has identified human skeletal remains with lesions suggestive of and consistent with treponematosis. A population and epidemiological approach was utilised to compare the MDM site to geographically neighbouring skeletal samples from the Highland Beach mound (8PB11) (ad 600–1200) and Fort Center (8GL12) (ad 1–500/1000). These samples were then integrated with data from previous research on proliferative skeletal lesion prevalence on the Gulf Coast of Florida. Population comparisons suggest a higher prevalence of proliferative skeletal lesions in Atlantic coastal populations as opposed to the nearest sampled site from the interior (p < 0.00001), a trend seemingly different from Gulf Coast populations. This investigation details the presence of treponemal disease in the Everglades archaeological region likely as early as ad 400, and the southern terminus in the contiguous United States that treponematosis has been reported. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
28.
A palynological investigation of lower Paleocene (lower Teurian) marine sediments of the Abbotsford Formation, exposed in the Fairfield Quarry, Dunedin, New Zealand, reveals a well-preserved association of dinoflagellate cysts and miospores. Thirty-six dinoflagellate species representing 26 genera were recorded, including one new peridinioid dinoflagellate species, Trithyrodinium partridgei characterized by a three-layered wall and a distinct brown, foveolate mesophragm. Trithyrodinium partridgei has a narrow range and at Fairfield Quarry co-occurs with typical New Zealand late Danian to Selandian index species such as Glaphyrocysta perforata and Alterbidinium pentaradiatum; hence it may prove an additional useful stratigraphic marker. The terrestrial palynomorph assemblage from samples within the range of Trithyrodinium partridgei includes 36 spore-pollen species dominated by the podocarp pollen Phyllocladidites mawsonii. The presence of Nothofagidites waipawaensis and Tricolpites phillipsii confirms a Paleocene age for the assemblage. The abundance of terrestrial palynomorphs and the composition of the dinocyst assemblages suggest a marine nearshore depositional environment.  相似文献   
29.
Environmentally-related wear conditions and pathologies affecting the dentition of fossil lungfish from freshwater deposits in Australia have been analysed and compared with similar changes in the dentition of the living Australian lungfish, Neoceratodus forsten. Fossil populations from the Namba, Etadunna, Wipajiri and Katipiri formations in central Australia, and the Carl Creek Limestone and the Camfield beds in northern Australia were assessed.

Tooth plates from populations of living lungfish from the Brisbane River and Enoggera Reservoir in southeast Queensland were analysed for comparison. Tooth plates were measured to determine the numbers of different age groups in each population. They were assessed for abrasion, attrition, spur and step wear, erosion and caries, and for trauma and pathological conditions such as malocclusion, hyperplasia, abscesses, osteopenia and parasitic damage. AH of these conditions are related to the environment where the fish lived, are found in living members of the group, and can be compared directly with those of fossil relatives.

The results suggest that some of the fossil populations were at risk before climatic changes late in the Cainozoic destroyed their habitats. Some fossil lungfish populations, such as those of the Wipajiri Formation, exhibit active spawning and recruitment, good growth rates and a low incidence of disease and environmentally related damage to the tooth plates. Others, like those of the Katipiri and Namba Formations, include no young, and the adult fish were ageing and show environmentally-related damage to the dentition. Etadunna lungfish had active recruitment, but the tooth plates show a high incidence of attrition and caries. Riversleigh lungfish were actively spawning but did not grow large. Tooth plates from this latter deposit have a high incidence of pathological conditions. Fish from the Camfield Beds, where food was severely limiting, had little serious pathology but high levels of caries. Pathologies among living lungfish are common, but fossil fish were comparatively healthy, with few serious dental problems. Information from studies of fossil lungfish confirms that conservation of the few living species of lungfish depends on the maintenance of clean environments that provide adequate supplies of food and suitable sites for spawning and for the growth of young fish.  相似文献   
30.
Coutts, F.J., Gehling, J.G. & García-Bellido, D.C., August 2016. How diverse were early animal communities? An example from Ediacara Conservation Park, Flinders Ranges, South Australia. Alcheringa 40, xxx–xxx. ISSN 0311-5518

Fossils of the Ediacara biota record the earliest evidence of animal communities and, as such, provide an invaluable glimpse into the abiotic and biotic processes that helped shape the evolution of complex life on Earth. A diverse community of Ediacaran macro-organisms is preserved with high resolution in a fossil bed recently excavated from north Ediacara Conservation Park (NECP) in the Flinders Ranges, South Australia. Many of the commonly described Ediacaran taxa from the Flinders Ranges are represented on the bed surface and include: Parvancorina, Rugoconites, Spriggina, Dickinsonia, Tribrachidium, Kimberella, Charniodiscus and Yorgia, including two new taxa. Numerous additional fossil-bed fragments from the same locality were analysed that preserve a similar suite of taxa and shared sedimentology. On all surfaces, preserved microbial mat appeared complex, both in topography and in texture, and the unique combination of fine grainsize, high diversity and trace fossils provide insights into the palaeoecology of the ancient organisms that lived during the Ediacaran Period some 550 Ma. Several trace fossils are overlapped by body fossils, indicative of successive events, and complex organismal behaviour. The complexity of this fossil surface suggests that the primordial community was relatively mature and possibly at late-stage succession.

Felicity J Coutts [], School of Biological Sciences, University of Adelaide, Adelaide 5000, South Australia, Australia. James G Gehling [], South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia. Diego C. García-Bellido [], South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia.  相似文献   
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