Late Cretaceous continental and marine vertebrate assemblages of the Laño Quarry (Basque-Cantabrian Region, Iberian Peninsula): an update

The vertebrate-bearing beds of the Laño quarry (Condado de Treviño) are among the most relevant sites from the Late Cretaceous of Europe. Geologically, Laño and the adjacent region are set on the southern limb of the South-Cantabrian Synclinorium (SE Basque-Cantabrian Region, northern Iberian Peninsula). The Laño sites were discovered in 1984; thousands of bones and teeth, including microfossils, have been collected during the prospection in the field and excavation campaigns. The vertebrate remains occur at two different stratigraphic horizons within a continental to shallow marine succession of Late Campanian-Maastrichtian age. The lower horizon contains the Laño 1 and Laño 2 sites, whereas the upper horizon contains the Albaina site. In the Laño sites, three fossiliferous beds (called L1A, L1B and L2) are known within an alluvial system composed mainly of fluvial sands and silts. The sedimentary structures are consistent with channel areas within an extensive braided river system. Based mainly on stratigraphic correlations, the fluvial beds of Laño are regarded as Late Campanian to Early Maastrichtian in age. These deposits have yielded a very diverse vertebrate assemblage, which consists of nearly 40 species, including actinopterygians, lissamphibians, lepidosaurs, turtles, crocodyliforms, dinosaurs, pterosaurs, and mammals. Seven genera and ten species have been erected to date in Laño. With reference to the marine vertebrate association of Albaina, it consists of at least 37 species, including sharks and rays, actinopterygians, mosasaurids, and plesiosaurs. Two genera and species of rhinobatoids (family indet.) and two new species of rhinobatids have been erected in Albaina. The fossil association indicates a Late (but not latest) Maastrichtian age. Recently, isolated turtle and dinosaur fossils have been discovered in the sublittoral beds of Albaina. The Laño quarry is one of the most noteworthy Campanian-Maastrichtian vertebrate localities of Europe by its taxonomic diversity, and provides useful information about the composition and affinities of both continental and marine vertebrate faunas from the latest Cretaceous of southwestern Europe.Los niveles con fósiles de vertebrados de la cantera de Laño (Condado de Treviño) se cuentan entre los más importantes del Cretácico Superior de Europa. Desde un punto de vista geológico, Laño y la región adyacente forman parte del flanco sur del Sinclinorio Subcantábrico (SE de la Región Vasco-Cantábrica). El descubrimiento de los niveles fosilíferos remonta a 1984; las prospecciones de campo y las campañas de excavación han proporcionado miles de huesos y dientes, incluyendo microfósiles. Los restos de vertebrados aparecen en dos horizontes estratigráficos diferentes formando parte de una sucesión continental a marina litoral de edad Campaniense superior a Maastrichtiense. El horizonte inferior contiene los yacimientos de Laño 1 y Laño 2, mientras que el superior contiene solo uno: Albaina. En los yacimientos de Laño, se reconocen tres niveles fosilíferos (llamados L1A, L1B y L2) formados en el seno de un sistema aluvial compuesto por arenas y limos fluviales. Las estructuras sedimentarias indican áreas de canal dentro de un sistema trenzado muy extendido. Según las correlaciones estratigráficas, los depósitos fluviales de Laño son de edad Campaniense superior a Maastrichtiense inferior. Estos depósitos han proporcionado una asociación muy diversa de vertebrados, que consiste en cerca de 40 especies, incluyendo actinopterigios, lisanfibios, lepidosaurios, tortugas, cocodrilos, dinosaurios, pterosaurios y mamíferos. En Laño se han definido hasta el momento siete géneros y diez especies. Por lo que respecta a la asociación de vertebrados marinos de Albaina, se han reconocido al menos 37 especies, que incluyen tiburones y rayas, actinopterigios, mosasaurios y plesiosaurios. Hasta la fecha se han definido en Albaina cuatro nuevos rinobatoideos: dos especies de rinobátidos y dos géneros y especies cuya familia es indeterminada. La asociación fósil es de edad Maastrichtiense superior no terminal. Recientemente se ha descrito el hallazgo de restos fósiles aislados de tortugas y dinosaurios en los niveles marinos de Albaina. La cantera de Laño es una de las localidades de vertebrados más destacadas del Campaniense-Maastrichtiense por su diversidad taxonómica, y proporciona información relevante sobre la composición y afinidades de las faunas de vertebrados continentales y marinos del Cretácico final del suroeste de Europa

Biogéographie de Madagascar = Biogeography of Madagascar

La proximité géographique entre Madagascar et l'Afrique a souvent conduit à rechercher la source du peuplement malgache en Afrique. De nouvelles données paléogéographiques permettent d'envisager une autre origine pour une partie de la faune de Madagascar. A la fin du Crétacé, une communication terrestre s'est établie entre l'Asie et l'Inde qui occupait alors une position encore très méridionale. L'Inde était alors encore très proche de Madagascar. Le plateau des Seychelles s'intercalait entre ces deux plaques et a pu fonctionner comme une communication entre elles. On peut supposer, à titre d'hypothèse, qu'une telle connexion a pu permettre le passage, depuis la Laurasie, de certains groupes comme, par exemple les Iguanidés (lézards) et les Boïnés (serpents). Ces deux groupes, aujourd'hui absents de Laurasie et d'Afrique, avaient atteint la Laurasie à la fin du Crétacé et au début du Tertiaire. En supposant que l'absence de ces deux groupes à l'état fossile en Afrique n'est pas une lacune de nos connaissances, cette hypothèse d'une voie Laurasie-Inde permet d'expliquer leur présence (et celle d'autres groupes : Lémuriens ?) à Madagascar. Ceci n'est pas incompatible avec des échanges avec l'Afrique. (Résumé d'auteur

Amphibians and squamate reptiles from the Cenomanian (Late Cretaceous) of Charentes, France.

International audienc

An enamel-like tissue, osteodermine, on the osteoderms of a fossil anguid (Glyptosaurinae) lizard

International audienceThe Glyptosaurinae, a fossil clade of anguid lizards, have robust osteoderms, with a granular ornamentation consisting of tubercles. In this study, the structural and histological features of these osteoderms are described in order to reconstruct their developmental pattern and further document the possible homology that could exist between vertebrate integumentary skeletons. Glyptosaurine osteoderms display a diploe architecture and an unusually complex structure that includes four tissue types: an intensely remodeled core of woven-fibered bone, a thick basal layer of lamellar bone, a peripheral ring exhibiting histological features intermediate between these two tissues and containing dense bundles of long Sharpey fibers, and a superficial layer made of a monorefringent, acellular and highly mineralized material, different from bone, and comparable in many respects to hypermineralized tissues such as ganoine, enameloids and enamel. We call this tissue osteodermine. The growth pattern of glyptosaurine osteoderms is likely to have involved first metaplasia, at an early developmental stage, then appositional growth due to osteoblast activity. The superficial layer that is well developed at the tubercle level must have resulted from epidermal and dermal contributions, a conclusion that would support previous hypotheses on the role of epidermal-dermal interactions in the formation of squamate osteoderms. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved

Middle Maastrichtian vertebrates (fishes, amphibians, dinosaurs and other reptiles, mammals) from Pajcha Pata (Bolivia) : biostratigraphic, paleoecologic and paleobiogeographic implications

The Pajcha Pata fossil locality in south central Bolivia, in the upper part of the Lower Member of the El Molino Formation, is the first late Cretaceous fauna in South America which has yielded, in addition to some invertebrates and plants, all kinds of vertebrates except birds, but including dinosaurs and mammals. its middle Maastrichtian age, indicated by geochronologic data, is consistent with the fauna, including the marine ichthyofauna. The vertebrate fossils reported here come from the main fossiliferous level which includes terrestrial, freshwater and marine taxa: vertebrates, Mammalia (both tribosphenic and nontribosphenic therians), Theropoda (Coelurosauria and Sauropoda), Crocodylia, Squamata (Serpentes), Chelonia, Amphibia (Anura, Gymnophiona, Caudata) and fish (Dipnoi, Teleostei, Actinopteri, Cladistia, Chondrostei); invertebrates (Gastropoda, Bryozoa) and plants (charophytes). Amongst these taxa are the earliest records of some fish, Amphibia and tribosphenic Mammalia in South America and/or in the world. The fish concerned are: Polypteriformes (Latinopollia suarezi), Siluriformes of the family Andinichthyidae (Andinichthys) and two new families, Osteoglossiformes of the subfamily Heterotidinae (Osteoglossidae), Perciformes of the family Latidae, Dipnoi of the family Lepidosirenidae (Lepidosiren cf. paradoxa). The Amphibia concerned are: indeterminate Gymnophiona, Noterpetontidae (Noterpeton bolivianum). Pajcha Pata is the only known locality in South America with both non-tribosphenic and tribosphenic therian mammals. The depositional environment was probably estuarian or lagoonal as indicated by a mixed continental, freshwater, and marine fauna. Comparison of this: local fauna with faunas of the same age at localities: belonging to the same proximal part of the El Molino basin on one hand, and with others belonging to the distal part on the other hand, shows that the two continental areas seem to have their own endemic freshwater fish fauna (except the Characidae and the Lepisosteidae, known in all levels of Bolivia). However, these two areas have the same marine taxa. This implies some influence of the sea in the whole basin. Calculated temperatures of the marine waters rangefrom 13 to 17 degrees for a latitute of about 22 degreesS, implying a southern Pacific upwelling. The El Molino Basin could have been also connected with the open sea through present-day Argentina and not only Venezuela as thought until now

Clinical safety of a polyvalent F(ab')2 equine antivenom in 223 African snake envenomations : a field trial in Cameroon

A large-scale clinical trial was conducted, according to World Health Organization Good Clinical Practice guidelines, in 7 centres in North Cameroon to determine the safety and efficacy of a polyvalent antivenom composed of purified F(ab')2. This study included 223 patients presenting clinically with an obvious snake bite, predominantly due to #Echis ocellatus$ (viper), the most abundant species in this savannah region. Clinical surveillance was maintained for 5 d in all patients and until the twenty-sixth day in 74% of cases. Two 10 mL ampoules of polyvalent F(ab')2 equine antivenom (Ipser Africa (TM)) were administered to each patient by intravenous infusion. If necessary, treatment was repeated 1 h after the end of the first infusion, and then with a frequency determined by the patient's clinical condition. Before initiation of antivenom treatment, the main clinical disorders observed on admission were oedema (93.7%) and haemorrhage (48.9%), with a clotting time longer than 30 min in 65.4% of patients. Clincal cure was obtained in 213 patients (96.8%). No amputation was necessary, and the case fatality rate was only 1.3%. On average, 4.6 (+ or - 3.7) ampoules were administered per patient ; 43% of subjects recovered after only a single infusion of 2 ampoules. Early adverse reactions, of varying degrees of severity, were observed in 6.3% of patients. A severe early reaction, anaphylactic shock, was observed in only one patient (0.4%). Serum sickness was observed in another patient. Polyvalent F(ab')2 equine antivenom given by repeated 20 mL intravenous infusions is a safe and effective treatment for envenomation caused by African vipers. (Résumé d'auteur

Lower Eocene lacustrine record in Loza (Southern Basque-Cantabrian Basin): Biostratigraphic and paleoclimatic inferences.

This research was supported by one Ramón y Cajal grant (JB), and projects CGL2004-0780, CGL2005-01712BTE, GIU 05/49 and 9/upv00121.310-15303/2003Peer Reviewe