New sharks and fishes faunas from the South of Germany (Schömberg) and the Grand Duchy of Luxembourg (Dudelange) toarcian

This paper introduces the faunal lists of 2 new Toarcian microvertebrates localities. Particular specimens are highlighted. The Middle Toarcian faunas have a modern look, because of the prominent Galeomorphii and Squalea diversity; such is the Schömberg (D) fauna, very near to the Lorraine synchronous list, but the Upper Toarcian Dudelange (L) fauna keeps “an ancient look” with 2 Hybodontid components (of which a new species of Lissodus), probably due to a different ecosystem, leading the predators to a crushing type diet, confirmed by the abundant batomorphs, but associated to a very modern functional highly secant morphotype, for which a new genus, Microtoxodus, is created, based on arrow-head teeth evoking the cookie-cutter Isistius’ teeth.Les listes faunistiques de deux gisements toarciens à microvertébrés sont présentées. La diversité et l'abondance des Galéomorphes et des Squalea donne à la faune du Toarcien moyen d'Allemagne du Sud (Schômberg) un cachet très moderne, semblable à ce qui est connu en Lorraine dans les couches à Crassum, alors que la faune du Toarcien supérieur de Dudelange (L), marquée par la présence de deux Hybodontiformes (dont une nouvelle espèce de Lissodus) et de Batomorphes, donc des prédateurs à dentition broyeuse, reflète probablement un écosystème différent. Les deux faunes ont en commun un élément hautement sécant, placé dans un genre nouveau, Microtoxodus, basé sur des dents en pointe de flèche, évoquant celles du requin actuel Isistius

PLIENSBACHIAN (EARLY JURASSIC) ICHTHYOFAUNA FROM LORRAINE AND THE ARDENNES (FRANCE) : FIRST RESULTS.

Surface rocks sampling (APMA – Sedan), rocks and sediments processing (NNHM Luxembourg and Museum-Aquarium of Nancy) offer a large bulk of ichthyoliths from Lorraine and the Ardennes (France) Pliensbachian (Davoei to Spinatum Zones). The preliminary faunal list includes Neoselachii (Synechodus, Paraorthacodus, Agaleus, Hexanchidae), Holocephali (Chimaeroid dorsal fin spine, myriacanthid or chimaeroid dorsal fin spine denticles, chimaeroid frontal clasper denticles) and Actinopterygii (Ptycholepis, Eugnathidae, Proleptolepis). The Synechodontiforms contain new species. Agaleus had already been reported from the French (Le Mans, Sarthe) Pliensbachian (BIDDLE, 1993), bearing in mind an earlier report from the Nancy Pliensbachian, under Ginglymostoma identification (LAMAUD, 1979). Chimaeroid denticles (see DUFFIN and REYNDERS, 1995) bring a second pliensbachian occurrence of modern type chimaeras, after the English Eomanodon simmsi (WARD and DUFFIN, 1989). Among the Actinopterygii, Proleptolepis isolated bones are found in (probably reptilian) coproliths, like Proleptolepis from the English Sinemurian ; Eugnathus is evoked by centimetric high teeth ; Ptycholepis is identified from scales ; among the otoliths, some are probably Leptolepiforms (see DELSATE, 1999). The Ardennes and Lorraine fauna is compared to the Danish (REES, 1998), Swedish (REES, 2000) and Le Mans faunal lists.Des récoltes de surface (APMA-Sedan) et le traitement physico-chimique de roches et sédiments (Musée national d’Histoire naturelle de Luxembourg et Musée-Aquarium de Nancy) ont fourni de nombreux ichthyolithes du Pliensbachien de Lorraine et des Ardennes (France). La liste faunique préliminaire comprend des Néosélaciens (Synechodus, Paraorthacodus, Agaleus, Hexanchidae), des Holocéphales (aiguillon dorsal de ?Chiméroïde, denticules du tenaculum frontal de Chiméroïde, denticules d’aiguillon dorsal de Myriacanthide ou Chiméroïde) et des Actinoptérygiens (Ptycholepis, ?Eugnathidae, Proleptolepis). Les Synéchodontiformes comptent de nouvelles espèces. Agaleus a déjà été signalé du Pliensbachien de France (Le Mans, Sarthe), quoique connu très tôt de Nancy sous l’identification « Ginglymostoma ». Les denticules de Chimaeroidei constituent une seconde occurrence pliensbachienne de chimères de type moderne, après l’Angleterre. Parmi les Actinoptérygiens, Proleptolepis a été trouvé à l’état d’os isolés au sein de coprolithes (probablement reptiliens), comme Proleptolepis du Sinémurien anglais ; Eugnathus est évoqué par de hautes dents centimétriques ; Ptycholepis est identifié par des écailles ; parmi les otolithes, certains sont attribuables aux Leptolepiformes. La faune des Ardennes et de Lorraine est comparée à celle du Danemark, de Suède et du Mans

FIRST DISCOVERY OF A DEFINABLE FLYING REPTILE (PTEROSAURIA, DORYGNATHUS CF BANTHENSIS) FROM THE LOWER TOARCIAN (LOWER JURASSIC) OF NANCY (LORRAINE, FRANCE).

Definable pterosaurian remains from the French Toarcian are reported for the first time. They are briefly described and referred to Dorygnathus cf banthensis. Before this discovery, Toarcian pterosaurs were only found from Germany, England and India.Un ptérosaure toarcien français est brièvement décrit, et attribué à Dorygnathus cf banthensis. Il s’agit non seulement du premier reptile volant toarcien français subcomplet déterminable, mais également de la seule occurrence du genre hors Allemagne

Pachycormid fish fed on octobrachian cephalopods: new evidence from the ‘Schistes bitumineux’ (early Toarcian) of southern Luxembourg

A re-examination of the early Toarcian fish fossils preserved in public paleontological collections in Luxembourg revealed 70 specimens of large Toarcian pachycormid fish with an excellent three-dimensional preservation within calcareous nodules. Six of them are associated with octobrachian coleoid gladii in their oesophagus or stomach, an association not previously described from Luxembourg. The pachycormids are ascribed to Pachycormus macropterus (Blainville, 1818) and Saurostomus esocinus Agassiz, 1843 while the octobrachian gladii are ascribed to Teudopsis bollensis Voltz, 1836, Teudopsis sp. indet. and Loligosepiidae indet. The position and orientation of the gladii provide direct evidence of these fishes feeding on coleoids and thus a teuthophagous diet, rather than an accidental joint burial. Together with evidence from coeval deposits in Germany, these findings suggest that teuthophagy was a widespread feeding strategy at the base of the clade that contains the suspension-feeding pachycormid giants of the Jurassic–Cretaceous

Scythes, sickles and other blades: Defining the diversity of pectoral fin morphotypes in Pachycormiformes

The traditional terminology of 'scythe' or 'sickle' shaped is observed to be flawed as an effective descriptor for pectoral fin shape in pachycormids. The diversity of pachycormid pectoral fin shapes is assessed across the 14 recognised genera that preserve complete pectoral fins, and improved terms are defined to more effectively describe their form, supported by anatomical observation and aspect ratio analysis of individual fins, and corroborated by landmark analysis. Three clear and distinct pectoral fin structural morphotypes emerge (falceform, gladiform, falcataform), reflecting a diversity of pachycormid lifestyles throughout the Mesozoic, from agile pursuit predator to slow-cruising suspension feeder

First rays (Chondrichthyes-Elasmobranchii) in the lower Jurassic of the Paris Basin

2009-08-25T12:24:32