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Were all Devonian seeds cupulate? A reinvestigation of Pseudosporogonites Hallei, Xenotheca Bertrandii and Aglosperma spp.
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Premise of research. Although the most comprehensively known Devonian seeds were borne in a “telomic” cupule, those of some species have been postulated as being borne terminally on naked axes lacking a cupule. Uncertainty remains as to whether such seeds were shed from a cupule before preservation. We reinvestigate the Upper Devonian fossils Pseudosporogonites hallei and Xenotheca bertrandii from Belgium and the similar ovules Aglosperma quadrapartita and Aglosperma avonensis from Britain and Aglosperma sp. from North America to consider their structure and organization and to determine whether they were cupulate. Methodology. Compressions/adpressions of X. bertrandii and Pseudosporogonites from Belgium and A. quadrapartita and A. avonensis from the United Kingdom, as well as Anglosperma sp. from Pennsylvania, were prepared, mainly by dégagement. Observation and photography were carried out using crossed polarizing filters. Pivotal results. Pseudosporogonites hallei, X. bertrandii, and A. quadrapartita comprise single ovules borne within small, radially symmetrical, uniovulate cupules. Integuments are entire at the chalaza but form flattened lobes distally. While a cupule is unknown in A. avonensis, its comparable integument morphology suggests that it was shed from a uniovulate cupule. Although the species are distinct from each other, their similarities show that they are closely related and belong to a single genus, for which the name Pseudosporogonites has priority. We emend P. hallei in light of our findings and erect the combinations P. bertrandii (Stockmans) C. Prestianni, J. Hilton et W. Cressler, P. quadrapartitus (J. Hilton et D. Edwards) C. Prestianni, J. Hilton et W. Cressler, and P. avonensis (J. Hilton) C. Prestianni, J. Hilton et W. Cressler. Conclusions. The uniovulate cupule in Pseudosporogonites is distinct from multiovulate telomic cupules of other Devonian seeds and expands the phenotypic diversity seen during the earliest phase of seed plant radiation, which was geologically instantaneous. Hydrasperman pollination in all proven Devonian seeds demonstrates evolution from a common ancestor, but finding morphological intermediates between seed and free-sporing plants remains a significant challenge to evolutionary plant biology.
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Possible evidence of mammoth hunting at the Neanderthal site of Spy (Belgium)
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Spy, a Belgian cave site famous for its Neanderthal remains, contains a wide spectrum of Pleistocene species. Horse, cave hyena, woolly mammoth, woolly rhinoceros and reindeer are the primary taxa. The Spy cave was used alternately by prehistoric humans and Pleistocene carnivores. This study considers whether prehistoric humans or carnivores are responsible for the large number of mammoth remains at the site. It is argued, on the basis of the frequency distribution of the skeletal elements of the mammoth, the age distribution of the mammoth molars, and the diet of the large carnivores and of the prehistoric humans, that the mammoth assemblage of Spy accumulated at the site through the activities of prehistoric humans. On the basis of AMS dates, the stratigraphic position of a number of mammoth molars and the absence of red ochre on the mammoth molars, it was concluded that these prehistoric humans were Neanderthals rather than Anatomically Modern Humans.
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Community structure of harpacticoid copepods in intertidal and shallow-water habitats of Cat Ba archipelago (Vietnam, South China Sea)
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The assemblage structure of harpacticoid copepods inhabiting the soft sediments of littoral and sublittoral areas of Cat Ba archipelago (South China Sea) is analysed. Three basic types of harpacticoid taxocenes were observed in the upper sublittoral. Main dominant species of taxocenes were Amphiascoides sp., Stenhelia latioperculata, Paramphiascella sp., Phyllopodopsyllus sp., Tisbe sp.1 and Amphiascoides sp. In addition, the main characteristics of harpacticoid species composition in littoral rock pools are described. A comparative analysis of shallow-water harpacticoid communities from different biotopes of the tropical region is presented, and shows that harpacticoid diversity and abundance are lowest in muddy sediments. Highest diversity and abundance are found in washed sands and silty sands with detritus. In general, the structure of muddy bottom communities is the most homogeneous throughout the tropics. Mangrove forests have no significant influence on harpacticoid taxocene structure. Harpacticoid associations of washed sands and silty sands with detritus demonstrate greater diversity and are region-specific.
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On the brink - investigating biodiversity in endangered crater lakes of the Amber Mountains National Park (Madagascar)
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Camels in the northern Provinces of the Roman Empire
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A peculiar case of intraspecific variability in the Chinese Notholca dongtingensis (Rotifera: Monogononta: Brachionidae)
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We review the rare Chinese rotifer Notholca dongtingensis Zhuge, Kutikova & Sudzuki, 1998, including abundant material collected during the winter months of 2009–2011 in and around the man-made Dishui Lake Southeast of Shanghai, PR China. Both an SEM study of its trophi and an account of its intraspecific variability are provided. The latter consists in particular of a unique and previously unknown type of spine formation involving the anterolateral spines, a character previously considered morphologically constant and even diagnostic in Notholca and related genera. The observations indicate that phenotypic plasticity invoked by a plesiomorphic triggering mechanism is not per se connected to the type or position of structures developed, but may activate responses resulting in the formation of quite different, autapomorphic structures throughout monogonont Rotifera.
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Optical dating of tidal sediments: Potentials and limits inferred from the North Sea coast
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Sequence mapping of Holocene coastal lowlands. The application of the Streif classification system in the Belgian coastal plain
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The Streif classification system: a tribute to an alternative system for organising and mapping Holocene coastal deposits
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DNA Barcoding Amphibians and Reptiles
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Only a few major research programs are currently targeting COI barcoding of amphibians and reptiles (including chelonians and crocodiles), two major groups of tetrapods. Amphibian and reptile species are typically old, strongly divergent, and contain deep conspecifi c lineages which might lead to problems in species assignment with incomplete reference databases. As far as known, there is no single pair of COI primers that will guarantee a suffi cient rate of success across all amphibian and reptile taxa, or within major subclades of amphibians and reptiles, which means that the PCR amplifi cation strategy needs to be adjusted depending on the specifi c research question. In general, many more amphibian and reptile taxa have been sequenced for 16S rDNA, which for some purposes may be a suitable complementary marker, at least until a more comprehensive COI reference database becomes available. DNA barcoding has successfully been used to identify amphibian larval stages (tadpoles) in species-rich tropical assemblages. Tissue sampling, DNA extraction, and amplifi cation of COI is straightforward in amphibians and reptiles. Single primer pairs are likely to have a failure rate between 5 and 50\% if taxa of a wide taxonomic range are targeted; in such cases the use of primer cocktails or subsequent hierarchical usage of different primer pairs is necessary. If the target group is taxonomically limited, many studies have followed a strategy of designing specifi c primers which then allow an easy and reliable amplifi cation of all samples.
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