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Galliformes, Upupiformes, Trogoniformes, and other avian remains (?Phaethontiformes and ?Threskiornithidae) from the Rupelian stratotype in Belgium, with comments on the identity of “Anas” benedeni Sharpe, 1899
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We describe new avian fossils from the Boom Formation of Belgium, which almost double the number of bird taxa known from this part of the Rupelian stratotype. Three galliform species can, at least tentatively, be assigned to the paraortygid species Paraortyx brancoi, P. lorteti, and Pirortyx major. Among the fossils is a partial sternum, which shows that Paraortyx lacks a spina interna. The absence of this structure is plesiomorphic for Galliformes and probably related to the absence of a large crop, thus indicating that Paraortygidae were not yet adapted to the regular processing of coarse and dry food. Two distal humeri belong to Trogoniformes (trogons) and Upupiformes (hoopoes, woodhoopoes, and allies), respectively. A femur is tentatively assigned to Phaethontiformes (tropicbirds), and a carpometacarpus is, likewise tentatively, referred to Threskiornithidae (ibises and spoonbills). We finally comment on the affinities of “Anas” benedeni Sharpe, 1899 and detail that this species most likely belongs to Gaviiformes (loons).
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A new species of Archaeoryctes from the Middle Paleocene of China and the phylogenetic diversification of Didymoconidae
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Didymoconidae are an enigmatic group of Asian endemic insectivorous mammals. We describe the new didymoconid species Archaeoryctes wangi sp. nov. from the Upper Member of the Wanghudun Formation (Middle Paleocene). This new species from the Qianshan Basin (Anhui Province, China) forms an interesting geographical intermediate between A. notialis from South China and A. borealis and A. euryalis from the Mongolian Plateau. To better understand the origin and evolutionary diversification of Didymoconidae, we performed a cladistic and stratocladistic study of the Didymoconidae and various outgroups. This study of dental material did not resolve the higher level affinities of Didymoconidae, but confirms the validity of the family and its distinctiveness from the morphologically similar Sarcodontidae. Moreover, our results corroborate the current didymoconid classification with the distinction of three subfamilies: “Ardynictinae”, Kennatheriinae and Didymoconinae; “Ardynictinae” are a paraphyletic stemgroup for the two other subfamilies. Our results suggest three distinct didymoconid radiations: (1) primitive ardynictines appeared in South China from the start of the Nongshanian; their evolution continues on the Mongolian Plateau with (2) the radiation of more evolved ardynictines and kennatheriines at the start of the Middle Eocene Arshantan and (3) the origin of didymoconines at the start of the Late Eocene Ergilian.
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The earliest Eocene mammal fauna of the Erquelinnes Sand Member near the French-Belgian border
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The earliest Eocene Erquelinnes site was discovered in 1880, but its mammal fauna has been frequently ignored. This paper provides the first detailed overview of the Erquelinnes mammals since 1929. The new faunal list doubles the known diversity at Erquelinnes to a total of 16 species, now also including amphilemurids, hyaenodontids, mesonychids, louisinids, equids and diacodexeids. The majority of the Erquelinnes species is also present in the earliest Eocene Dormaal MP7 reference fauna, with as most notable exceptions the presence of a potentially dwarfed specimen of Dissacus, and of two perissodactyl taxa at Erquelinnes. The ceratomorph perissodactyl Cymbalophus cuniculus is also known from the earliest Eocene of England, but a specimen identified as cf. Sifrhippus sandrae is closely similar to contemporaneous primitive North American equids. This specimen represents the oldest unambiguous European equid and highlights faunal similarities between Europe and North America during this time interval. Faunal differences between Erquelinnes and Dormaal seem mostly due to depositional differences, and the Erquelinnes fauna represents a typical earliest Eocene fauna, closely similar to other MP7 and PEI faunas in Europe.
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First evidence of reproductive adaptation to “Island effect” of a dwarf Cretaceous Romanian titanosaur, with embryonic integument in ovo
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Background: The Cretaceous vertebrate assemblages of Romania are famous for geographically endemic dwarfed dinosaur taxa. We report the first complete egg clutches of a dwarf lithostrotian titanosaur, from Totes¸ti, Romania, and its reproductive adaptation to the ‘‘island effect’’. Methodology/Findings: The egg clutches were discovered in sequential sedimentary layers of the Maastrichtian Saˆnpetru Formation, Totes¸ti. The occurrence of 11 homogenous clutches in successive strata suggests philopatry by the same dinosaur species, which laid clutches averaging four ,12 cm diameters eggs. The eggs and eggshells display numerous characters shared with the positively identified material from egg-bearing level 4 of the Auca Mahuevo (Patagonia,Argentina) nemegtosaurid lithostrotian nesting site. Microscopic embryonic integument with bacterial evidences was recovered in one egg. The millimeter-size embryonic integument displays micron size dermal papillae implying an early embryological stage at the time of death, likely corresponding to early organogenesis before the skeleton formation. Conclusions/Significance: The shared oological characters between the Hat¸eg specimens and their mainland relatives suggest a highly conservative reproductive template, while the nest decrease in egg numbers per clutch may reflect an adaptive trait to a smaller body size due to the ‘‘island effect’’. The combined presence of the lithostrotian egg and its embryo in the Early Cretaceous Gobi coupled with the oological similarities between the Hat¸eg and Auca Mahuevo oological material evidence that several titanosaur species migrated from Gondwana through the Hat¸eg Island before or during the Aptian/Albian. It also suggests that this island might have had episodic land bridges with the rest of the European archipelago and Asia deep into the Cretaceous.
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Towards a Global Phylogeny of the "Living Fossil" Crustacean Order of the Notostraca
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Extraordinary morphological changes in valve morphology during the ontogeny of several species of the Australian ostracod genus Bennelongia (Crustacea, Ostracoda).
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Oxyarietites boletzkyi n.gen., n.sp., nouveau genre et nouvelle espèce d’ammonite dans le Sinémurien inférieur de Bourgogne (France) : un rare précurseur des morphologies oxycônes pour le Jurassique.
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L’une des toutes premières ammonites à coquille presque oxycône observée dans les séries fossilifères après la crise faunique de la limite Trias/Jurassique est décrite. Elle provient du Sinémurien inférieur (chronozone à Semicostatum ou à Turneri) de Bourgogne (Mavilly-Mandelot, Côte-d’Or, France). Cette nouvelle forme, Oxyarietites boletzkyi n. gen., n. sp., possède une coquille involute, comprimée et carénée dont le type clairement suboxycône est nouveau pour le Sinémurien inférieur. En raison de son aire ventrale carénée, ce taxon se rattache probablement à la super-famille des Arietitoidea Hyatt, 1875 sensu Guex (1995) mais son attribution familiale est incertaine et son origine évolutive reste énigmatique. Outre son intérêt taxonomique, cette découverte est importante car elle pose le problème de la valeur adaptative des caractères liés à la géométrie des coquilles d’ammonites. Il est actuellement admis que les coquilles involutes, comprimées et carénées de type suboxycône et oxycône favorisent significativement l’hydrodynamisme et donc la mobilité des espèces qui les possèdent. Il est surprenant que l’acquisition de ce probable avantage adaptatif n’ait pas favorisé l’implantation au sein des peuplements du nouveau taxon, qui reste une forme rare. Dans tous les cas, la découverte d’O. boletzkyi n. gen., n. sp. rajeunit d’environ 2 millions d’années la mise en place des morphologies oxycônes au cours de la phase de reconstitution de la biodiversité post-crise Trias/Jurassique. Oxyarietites boletzkyi n.gen., n. sp., a new genus and species of ammonite for the Lower Sinemurian of Burgundy (France): a rare forerunner of the oxycone morphologies for the Jurassic. One of the very first quasi-oxycone ammonites following the Triassic/Jurassic boundary crisis is described. It was collected from the fossiliferous Lower Sinemurian (Semicostatum or Turneri Chronozone) strata of Burgundy (Mavilly-Mandelot, Côte-d’Or, France). The new taxon, Oxyarietites boletzkyi n. gen., n.sp., possesses an involute, compressed and keeled shell of suboxycone morphology, a shell type previously unknown for the Lower Sinemurian. The discovery makes younger by about 2 Ma the emergence of keeled (sub)oxycone shells following the Triassic/Jurassic boundary crisis. Its obviously keeled ventral area allows a probable assignation to the Arietitoidea Hyatt, 1875 sensu Guex (1995) superfamily, but family level assignation and its evolutionary origin remain obscure. Although, it is generally accepted that involute, compressed and keeled suboxycone and oxycone ammonite shells possess the best hydrodynamical abilities and mobility, the acquisition of this probable adaptive advantage in O. boletzkyi n. gen., n. sp. does not go together with abundancy in the fossil record.
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The Dababiya Corehole, Upper Nile Valley, Egypt: Preliminary results.
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The Dababiya corehole was drilled in the Dababiya Quarry (Upper Nile Valley, Egypt), adjacent to the GSSP for the Paleocene/ Eocene boundary, to a total depth of 140 m and bottomed in the lower Maastrichtian Globotruncana aegyptiaca Zone of the Dakhla Shale Formation. Preliminary integrated studies on calcareous plankton (foraminifera, nannoplankton), benthic foraminifera, dinoflagellates, ammonites, geochemistry, clay mineralogy and geophysical logging indicate that: 1) The K/P boundary lies between 80.4 and 80.2 m, the Danian/Selandian boundary between ~ 41 and 43 m, the Selandian/Thanetian boundary at ~ 30 m (within the mid-part of the Tarawan Chalk) and the Paleocene/Eocene boundary at 11.75 m (base [planktonic foraminifera] Zone E1 and [calcareous nannoplankton] Zone NP9b); 2) the Dababiya Quarry Member (=Paleocene/Eocene Thermal Maximum interval) extends from 11.75 to 9.5 m, which is ~1 m less than in the adjacent GSSP outcrop.; 3) the Late Cretaceous (Maastrichtian) depositional environment was nearshore, tropical-sub tropical and nutrient rich; the latest Maastrichtian somewhat more restricted (coastal); and the early Danian cooler, low(er) salinity with increasing warmth and depth of water (i.e., more open water); 4) the Paleocene is further characterized by outer shelf (~ 200 m), warm water environments as supported by foraminifera P/B ratios > 85% (~79-28 m), whereas benthic foraminifera dominate (>70%) from ~27-12 m (Tarawan Chalk and Hanadi Member) due, perhaps, in part to increased dissolution (as observed in nearby outcrop samples over this interval); 5) during the PETM, enhanced hydrodynamic conditions are inferred to have occurred on the sea-floor with increased river discharge (in agreement with sedimentologic evidence), itself a likely cause for very high enhanced biological productivity on the epicontinental shelf of Egypt; 6) correlation of in situ measured geophysical logs of Natural Gamma Ray (GR), Single-Point Resistance (PR), Self-Potential (SP), magnetic susceptibility(MS), and Resistivity, and Short Normal (SN) and Long Normal (LN) showed correspondence to the lithologic units. The Dababiya Quarry Member, in particular, is characterized by very high Gamma Ray and Resistivity Short Normal values.
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What's the internet doing to our brains?
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Actieplan zeehond van defensief naar offensief milieubeleid in de Noordzee.
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