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Crossing epoch and international boundaries: The earliest Eocene Erquelinnes mammal fauna from the Mons Basin and its correlation
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In 1880, the fluvial “Upper Landenian” deposits (Tienen Formation) of the Erquelinnes sand quarry in the southern part of the Mons basin near the Belgian-French border yielded their first mammal fossil, a well preserved jaw of a primitive perissodactyl. By 1927, about 40 mammal specimens had been found at Erquelinnes and had been attributed to Adapisorex, ‘Protomomys’, Paramys, Plesiadapis, Arctocyonides, Hyracotherium, Coryphodon and ‘Oxyaena or Miacidae’. By that time however, the Erquelinnes fauna had already been eclipsed by the contemporaneous Dormaal fauna from northeastern Belgium, which yielded thousands of specimens and has since become the international MP7 reference level for the earliest Eocene of Europe. Meanwhile, attention for the Erquelinnes fauna has been limited to passing mentions of referred specimens in the formal descriptions of the new plesiadapiform Platychoerops georgei and of the miacid carnivoran Gracilocyon solei. Here we present an updated faunal list for the complete Erquelinnes mammal fauna. We show that also hyaenodontids, mesonychids, hyopsodontids, and dichobunid artiodactyls are present, and some of the earlier identifications are corrected or detailed further. This update of the Erquelinnes mammal fauna almost doubles its diversity, and strengthens the correlation with the Dormaal MP7 reference fauna. The results of the δ13Corg analysis of the strata underlying and coeval with the fluvial unit containing the Erquelinnes mammal fauna seem to independently support the faunal correlation and earliest Eocene age Sedimentological observations and δ13Corg analysis recently obtained in fluvial and lignitic sediments from the nearby Avesnois area in northern France (Quesnel et al, this meeting) moreover allow the correlation of the “Upper Landenian” fluvial deposits from the Belgian Erquelinnes locality with those of the “Sparnacian” in France. Remaining faunal differences between Erquelinnes and Dormaal are most likely the result of subtle differences in depositional environments and thus in taphonomic bias except, possibly, for the perissodactyl jaw collected in 1880. This specimen was not collected from the basal gravel bed of the Erquelinnes Sand Member like all other specimens, but from the overlying, cross-stratified sands. Iits morphology is unlike that of the perissodactyl found in the basal gravel bed at Erquelinnes or of any other Dormaal aged perissodactyl. Instead, it matches Cymbalophus cuniculus from slightly younger deposits in the London Basin. The perissodactyl jaw from Erquelinnes therefore either indicates an earlier first appearance for Cymbalophus, an unexpectedly long phase of deposition for the Erquelinnes Sand Mbr, or a combination of both.
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Small is Beautiful: the Erquelinnes mammal fauna from the earliest Eocene of the southern Mons Basin, belgium
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In 1880, the early Eocene fluvial deposits of the Erquelinnes sand quarry in the southern part of the Mons basin in Belgium yielded their first mammal fossil, a well preserved jaw of a primitive perissodactyl. By 1927, about 40 mammal specimens had been recovered from Erquelinnes and were attributed to Adapisorex, ‘Protomomys’, Paramys, Plesiadapis, Arctocyonides, Hyracotherium, Coryphodon and ‘Oxyaena or Miacidae’. By that time however, the Erquelinnes fauna had already been eclipsed by the contemporaneous Dormaal fauna from northeastern Belgium, which yielded thousands of specimens rather than only a few dozen. Since then, attention for the Erquelinnes fauna has therefore been limited to the passing mentions of referred specimens in the formal descriptions of the new plesiadapiform Platychoerops georgei and of the miacid Gracilocyon solei. Here we present an updated faunal list of the complete Erquelinnes mammal fauna. We show that also hyaenodontids, mesonychids, hyopsodontids, and dichobunid artiodactyls are present in the Erquelinnes fauna, and some of the earlier identifications are corrected or detailed further. This update of the Erquelinnes mammal fauna almost doubles its diversity, and strengthens the correlation with the earliest Eocene (MP7) Dormaal reference fauna. Results from δ13Corg analysis of the mammal-bearing level at Erquelinnes and the strata immediately below it, seem to independently support the faunal correlation. Faunal differences between Erquelinnes and Dormaal are most likely the result of subtle differences in depositional environments and thus in taphonomic bias. Details of the stratigraphic origin of the Erquelinnes perissodactyl specimens however show that these are derived from two distinct stratigraphic levels, which potentially have significantly different age correlations.
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Seismic stratigraphy of the late Quaternary sedimentary infill of Lac d’Armor (Kerguelen archipelago): a record of glacier retreat, sedimentary mass wasting and southern Westerly intensification.
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Lac d'Armor (49°27′S, 69°42′E) is a medium-sized, fjord-type lake located on the ‘Grande Terre’ island of the Kerguelen archipelago. A dense grid of high-resolution reflection seismic profiles was collected from this lake basin. The seismic stratigraphic facies reveal a last deglaciation to Holocene infill comparable to the seismic facies found in other glacigenic lakes all over the world. Remarkable features in the seismic stratigraphy are mounded structures found at the southern edge of both sub-basins. The sediment mounds can be interpreted as sediment drifts created by wind-induced bottom currents. The onset of the build-up of these drifts initiated at some point in the Holocene and indicates a strengthening of the southern Westerlies, which are currently the dominant winds on this island.
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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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The magnitude of global marine species diversity.
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The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered.
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New species in the Old World: Europe as a frontier in biodiversity exploration, a test bed for 21st century taxonomy.
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The number of described species on the planet is about 1.9 million, with ca. 17,000 new species described annually, mostly from the tropics. However, taxonomy is usually described as a science in crisis, lacking manpower and funding, a politically acknowledged problem known as the Taxonomic Impediment. Using data from the Fauna Europaea database and the Zoological Record, we show that contrary to general belief, developed and heavily-studied parts of the world are important reservoirs of unknown species. In Europe, new species of multicellular terrestrial and freshwater animals are being discovered and named at an unprecedented rate: since the 1950s, more than 770 new species are on average described each year from Europe, which add to the 125,000 terrestrial and freshwater multicellular species already known in this region. There is no sign of having reached a plateau that would allow for the assessment of the magnitude of European biodiversity. More remarkably, over 60\% of these new species are described by non-professional taxonomists. Amateurs are recognized as an essential part of the workforce in ecology and astronomy, but the magnitude of non-professional taxonomist contributions to alpha-taxonomy has not been fully realized until now. Our results stress the importance of developing a system that better supports and guides this formidable workforce, as we seek to overcome the Taxonomic Impediment and speed up the process of describing the planetary biodiversity before it is too late.
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The ‘rotiferologist’ effect and other global correlates of species richness in monogonont rotifers
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Towards a List of Available Names in Zoology , partim Phylum Rotifera
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Many, mostly older, names of animal species are nomenclaturally problematic, either because their orthography is unstable, or they cannot be linked reliably to a taxonomic identity, due to the lack of recognisable descriptions and/or types. Yet, they represent available (sensu International Code of Zoological Nomenclature) names and must be taken into account in zoological works. This situation, with available senior, yet dubious names confounding nomenclature, is undesirable. It creates uncertainties at a time when molecular approaches are revolutionizing our concepts of species diversity, and fails us when the current extinction crisis calls for efficient, accurate, and constructive approaches to document, monitor, and conserve biodiversity. The International Code of Zoological Nomenclature (The Code) provides a means to address this issue by restricting availability, application and orthography of names to those included in the List of Available Names in Zoology (LAN). The Code (Art. 79) allows an international body of zoologists in consultation with the Commission to propose a candidate part of the LAN for a major taxonomic field. We explore this possibility for 3570 species-group names of Phylum Rotifera (of which 665 are problematic), by presenting such a candidate Rotifera part of the LAN. The web site of the International Commission on Zoological Nomenclature (http://www.iczn.org) will hold both the candidate list and a forum to facilitate consultation on the candidate list, while the list itself also can already be freely downloaded from three other Internet sites: http://fada.biodiversity.be, http://rotifer.ansp.org/LAN, and www.hausdernatur.at/rotifera. We give here an overview of the general approach and procedures applied in preparation of the candidate list, and anticipate that our effort will promote the process as well as result in a standard list of names for use in taxonomy, the Global Names Architecture and other biodiversity information initiatives.
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Five New Species of Homoscleromorpha (Porifera) from the Caribbean Sea
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Five new species of Homoscleromorpha (Porifera) of four genera, Oscarella, Plakortis, Plakina and Corticium, are described from vertical walls of reef caves at depths ranging from 23 to 28 m in the Caribbean Sea. Oscarella nathaliae sp. nov. has a leaf-like thinly encrusting, flat body, loosely attached to the substrate and a perforated, not lobate surface. Oscarella nathaliae sp. nov. contains two bacterial morphotypes and is characterized by two mesohylar cell types with inclusions. Plakortis myrae sp. nov. has diods of two categories: abundant large ones (83–119 mm long) and rare small ones (67–71 mm long) with sinuous, S-bent centres; triods Y- or T-shaped (18–5 mm long), and abundant microrhabds (5–12 mm long). Plakortis edwardsi sp. nov. has diods of one category with thick, sinuous, S-bent centres (110 to 128 mm long); triods T-shaped (actines 28–59 mm long). It is the only species of this genus showing small diods (22–31 mm long). Plakortis dariae sp. nov. has diods of two categories: large ones (67–112 mm long) and small, rare, irregular ones, slightly curved, often deformed with one end blunt (30–59 mm long); triods rare and regular (actines 20–44 mm long long). Corticium diamantense sp. nov. has oscula situated near its border, regular non-lophose calthrops of one size class, very rare tetralophose calthrops and candelabra with the fourth actine ramified basally in 4–5 microspined rays. In addition, a re-description of Plakina jamaicensis Lehnert & van Soest 1998 is based on newly collected material and the type specimen. P. jamaicensis has a convoluted brainlike surface; well developed sub-ectosomal cavities; irregular sinuous diods, triods, calthrops, rare monolophose calthrops, rare dilophose calthrops, rare trilophose calthrops and common tetralophose calthrops. Molecular ‘barcoding’ sequences for mitochondrial cob are given for Plakortis edwardsi sp. nov., P. dariae sp. nov., Plakina jamaicensis and Corticium diamantense sp. nov. An identification key for all western Atlantic Homoscleromorpha is provided.
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