Search results

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.

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.

A new amphipod crustacean, Liljeborgia clytaemnestra sp. nov., is described based on specimens from Malta and the Bay of Naples. It is quite similar to the sympatric L. dellavallei Stebbing, 1906, but it has narrower and more regular-sized spines on the propodus of pereiopods 3–4. The longest spine on the dorsolateral border of the peduncle of uropod 1 is not strongly elongate in adult males, as in L. dellavallei. The apical spines on the lobes of the telson are much longer than in L. dellavallei. L. clytaemnestra sp. nov. is actually more similar to two northeastern Atlantic species, the British L. pallida (Spence Bate, 1857) and the Scandinavian L. brevicornis (Bruzelius, 1859) than to the Mediterranean L. dellavallei. In L. clytaemnestra sp. nov., article 2 of the mandibular palp has setae on distal third, whilst setae are restricted to tip in the two other species. Article 3 of the mandibular palp is also longer in L. clytaemnestra sp. nov. than in the two Atlantic species. The spines of the outer plate of the maxilliped are longer in L. clytaemnestra sp. nov. than in the two other species. The most distal spine of the propodus of pereiopods 3–4 is reduced in L. clytaemnestra sp. nov. and L. brevicornis, but not in L. pallida. The serration of the posterior border of the basis of pereiopod 7 is much stronger in L. clytaemnestra sp. nov. than in the two other species. Finally, in L. clytaemnestra sp. nov., the spines of the lobes of the telson are longer than in L. pallida. A lectotype is designated for L. dellavallei. The presence/absence of a posterodorsal tooth on pleonite 3 in L. dellavallei is discussed. The validity of L. kinahani (Spence Bate, 1862) is questioned. An identification key is proposed for Mediterranean Liljeborgia species.

Synthesis of species distributions and hotspots of endangerment is critical for setting conservation priorities to address the acute worldwide biodiversity crisis (Feeley and Silman 2011). Such a synthesis requires enormous efforts to access and unite widely dispersed biodiversity data and to establish open data archiving as a standard scientific practice. The essential first steps in this endeavor are locating primary biodiversity data—where, when, how, and by whom species have been observed or collected—and mak- ing this basic data available to the scientific community. Here, we report on a coordinated initiative of freshwater journals to stimulate a culture of publishing primary biodiversity data. Although freshwaters are tiny in their extent, they harbor a very large fraction of the global species richness, and they have experienced alarming rates of biodiversity decline (Dudgeon et al. 2006). However, freshwater biodiversity is generally neglected or grossly underrepresented in data- mobilization efforts. The importance of broad biodiversity compilations, however, has been increasingly recognized, especially in light of the establishment of the Intergovernmental Science–Policy Platform on Biodiversity and Ecosystem Services and the Group on Earth Observations’ Biodiversity Observation Network, and standards and tools have already been put in place to manage large sets of primary biodiversity data. In particular, the Global Biodiversity Information Facility (GBIF; www.gbif.org) collates and centralizes biodiversity information through its participant nodes, which include large topical initiatives such as the Ocean Biogeographic Information System (Costello and Vanden Berghe 2006) and the distributed database network for vertebrates, VertNet (Constable et al. 2010). BioFresh (www.freshwaterbiodiversity.eu), a European Union–funded project, serves the same purpose for the freshwater realm. Recent calls for data archiving in ecology (Whitlock 2011), together with the increasingly common requirement by funding agencies to deposit research data, will be instrumental in making primary biodiversity data available. There is no doubt, however, that scientific journals can and should also play a key role in promoting data-sharing policies (Huang and Qiao 2011). Consequently, we developed the following statement in collaboration with freshwater journal editors to strongly encourage the submission of species-distribution data: “Authors are encouraged to place all species distribution records in a publicly accessible database such as the national Global Biodiversity Information Facility (GBIF) nodes (www.gbif.org) or data centers endorsed by GBIF, including BioFresh (www.freshwaterbiodiversity.eu).” This statement is posted on http:// data.freshwaterbiodiversity.eu/submit data.html along with further instructions and will be widely published in the journals’ instructions for authors and on their Web sites. The editors and publishers of the following journals have approved the statement: Aquatic Botany, Aquatic Conservation: Marine and Freshwater Ecosystems, Aquatic Ecology, Aquatic Sciences, Ecology of Freshwater Fish, Freshwater Biology, Freshwater Reviews, Fundamental and Applied Limnology, Hydrobiologia, Inland Waters, the International Review of Hydrobiology, Freshwater Science (formerly, the Journal of the North American Benthological Society), the Journal of Fish Biology, the Journal of Limnology, the Journal of Plankton Research, Limnetica, Limnologica, Marine and Freshwater Research, and River Systems. Discussions are in prog- ress with an additional nine major journals in the field. What is the benefit to authors in following the recommendations for publishing primary biodiversity data? Certainly, promoting large-scale bio- diversity syntheses is an important idealistic motivation. However, as was outlined by Costello (2009), embrac- ing data-publishing practices also leads to increased recognition of scientists’ work. Papers connected to publicly available data are cited significantly more often, because the data become available for inclusion in broad-scale analyses (Piwowar et al. 2007), which are increasingly gaining importance. Importantly, the publication of primary biodiversity data is technically straightforward and quick, which minimizes the burden on authors. This is achieved by restricting submissions to a minimal standard set of fields, similar to the requirements for sequence submission to GenBank, a hugely successful database with great potential for supporting biodiversity science as well. Endorsement of the proposed data-publishing policy by most major freshwater journals will doubtlessly spur submission of primary biodiversity data, because it would raise awareness and could establish a culture of data publication. It should also encourage a wider range of journals in other areas of ecology and related fields to join the initiative. This would be of great benefit to scientific progress and to biodiversity conservation alike.