Billon-Bruyat J.-P.,Section darcheologie et paleontologie |
Mazin J.-M.,University Claude Bernard Lyon 1 |
Pouech J.,European Synchrotron Radiation Facility
Swiss Journal of Geosciences | Year: 2010
The spotty nature of the terrestrial fossil record for the Mesozoic hinders a more complete understanding of dinosaur diversity. For stegosaurs (Ornithischia), the plated dinosaurs, only a few and fragmentary remains are reported from the Early Cretaceous of Europe. A recent revision concluded that only a partial vertebra of the nomen dubium Craterosaurus (?Aptian, England) could be considered as stegosaurian. Here we report on a stegosaur tooth from the Early Cretaceous (Berriasian) Purbeckian deposits of Cherves-de-Cognac (Charente), southwestern France. This tiny tooth was examined in detail using microtomography. Comparisons being limited by the rarity of stegosaur tooth rows material (e. g., from the skull of the holotype of Stegosaurus stenops) and dental material, notably from Europe, we observed new material of cf. Stegosaurus armatus and Hesperosaurus mjosi from the Upper Jurassic Morrison Formation of Wyoming (USA). The tooth shows the most similarities to the Late Jurassic genera Stegosaurus and Hesperosaurus, but differs in having a distinctive downwardly arched (V-shaped) cingulum on the?lingual face (maxillary tooth hypothesis). It is referred to as Stegosauria indeterminate, a medium-sized quadrupedal herbivore that inhabited an emerged land between the Armorican Massif and the Massif Central. This finding is the first evidence of a stegosaur from the Early Cretaceous of France and a welcome addition to the meagre European record of that time. In addition, it is the second stegosaurian tooth crown reported from Europe. The assemblage of ornithischians of Cherves-de-Cognac shares some similarities with that of the Early Cretaceous (Berriasian) of the Purbeck Limestone Group, southern England. The relative rarity of ornithischian osteological remains in both Purbeckian environments suggests that most of these dinosaurs were mainly inhabitants of inland terrestrial palaeoenvironments. © 2010 Swiss Geological Society.
Philippe M.,French National Center for Scientific Research |
Billon-Bruyat J.-P.,Section darcheologie et paleontologie |
Garcia-Ramos J.C.,University of Oviedo |
Bocat L.,Section darcheologie et paleontologie |
And 2 more authors.
Palaeontology | Year: 2010
Previously known from the Kimmeridgian-Portlandian of Dorset (UK) only, Protocupressinoxylon purbeckensis wood is reported here from the Kimmeridgian of Asturias (Spain) and Ajoie (Switzerland). The morphospecies taxonomy and nomenclature are discussed, and new supplementary illustrations are given. The P. purbeckensis tree was growing in dry strongly seasonal (tropophilous) environments, and the new occurrences suggest that such a climate prevailed on land all over southwestern Europe at the end of the Jurassic (Kimmeridgian sensu anglico- Portlandian). The review of fossil wood data indicates that such a stressful environment may have constrained terrestrial biocoenoses and their evolution at the Jurassic/Cretaceous boundary. But wood generic diversity curves are also strikingly similar to that drawn 20 years ago for nonmarine tetrapods, implying a fossil Lagerstätte effect. © The Palaeontological Association.
Becker D.,Section Darcheologie et Paleontologie |
Antoine P.-O.,Montpellier University |
Maridet O.,CAS Institute of Vertebrate Paleontology and Paleoanthropology
Journal of Systematic Palaeontology | Year: 2013
A newly discovered, well-preserved skull and associated fragment of a juvenile mandible from the Early Oligocene locality of Poillat (Canton Jura, NW Switzerland), bearing close affinities with the rhinocerotid Protaceratherium albigense (Roman, 1912), are attributed to a new small-sized representative of early diverging Rhinocerotinae, Molassitherium delemontense gen. et sp. nov. Other specimens from Western Europe, formerly questionably referred to Epiaceratherium Abel, 1910, are assigned to this new genus. Comparison with the previously described Protaceratherium Abel, 1910 (including type material) and a phylogenetic analysis highlight the mismatch of Protaceratherium minutum (Cuvier, 1822) and Protaceratherium albigense (Roman, 1912). Given the topology of the most parsimonious tree, a basal split within Rhinocerotidae coincides with the well-supported divergence of the Elasmotheriinae and Rhinocerotinae clades. Relationships within Rhinocerotinae are [Epiaceratherium bolcense Abel, 1910 [Epiaceratherium magnum Uhlig, 1999 [Molassitherium gen. nov. [Mesaceratherium Heissig, 1969 [Pleuroceros Roger, 1898 [Protaceratherium minutum (Cuvier, 1822) [Plesiaceratherium mirallesi (Crusafont, Villalta and Truyols, 1955) [Aceratheriini, Rhinocerotini]]]]]]]]. The only paraphyletic genus in the analysis is Epiaceratherium, with the earliest Oligocene Epiaceratherium bolcense Abel, 1910 being sister taxon to an [Epiaceratherium magnum Uhlig, 1999, Rhinocerotinae] clade. In the single most parsimonious tree, Molassitherium gen. nov., included within the early diverging Rhinocerotinae, forms a clade encompassing Molassitherium delemontense gen. et sp. nov. and the type species Molassitherium albigense comb. nov. The range of Molassitherium delemontense gen. et sp. nov. is so far restricted to the late Early-early Late Oligocene interval in Western Europe (Germany, Switzerland, France; late MP22-MP25). © 2013 Copyright Taylor and Francis Group, LLC.
Anquetin J.,Section darcheologie et paleontologie |
Anquetin J.,French Natural History Museum |
Milner A.R.,Natural History Museum in London
Comptes Rendus - Palevol | Year: 2015
The enigmatic vertebrate taxon Cyrtura temnospondyla is reassessed following the location and reuniting of both counterparts. The specimen, comprising a series of caudal vertebrae from the Tithonian Solnhofen Limestone, has variously been interpreted as derived either from a temnospondyl amphibian, or a turtle, or to be indeterminate. The redescription of this caudal series reveals that the vertebrae have a single centrum, in contrast to previous descriptions. This specimen is here interpreted to be the tail of a turtle more derived than Proganochelys and Meiolania, but is otherwise indeterminate and cannot be associated with any of the diagnosed taxa from the Solnhofen Limestone. C. temnospondyla lacks any diagnostic character and must therefore be considered a nomen dubium. © 2014 Académie des sciences.
Puntener C.,Section Darcheologie et Paleontologie |
Billon-Bruyat J.-P.,Section Darcheologie et Paleontologie |
Bocat L.,Section Darcheologie et Paleontologie |
Berger J.-P.,University of Fribourg |
Joyce W.G.,University of Tübingen
Journal of Vertebrate Paleontology | Year: 2014
The fossil turtle Tropidemys langii is a representative of Plesiochelyidae, a traditionally recognized group of Late Jurassic turtles diagnosed by the presence of three cervical scutes and adapted to life in the sea. Tropidemys langii was previously only known from fossilized carapaces and, possibly, plastra from Europe, most notably the famous Solothurn Turtle Limestone of Switzerland. Due to the sparse fossil record of Tropidemys langii, several questions concerning its taxonomy and phylogeny have remained unanswered. Here, new material of Tropidemys langii is reported from the Kimmeridgian of Porrentruy, Canton Jura, Switzerland. In addition to three well-preserved carapaces, associated plastra and limb bones (humerus and femur) are described for the first time. The type specimens of Tropidemys valanginiensis and Pelobatochelys blakii lack diagnostic characters, but can nevertheless be referred to Tropidemys. A potential extension of the lineage into the Early Cretaceous is uncertain, however, because the type locality of Tropidemys valanginiensis is dubious. A cladistic analysis shows that Tropidemys langii is sister to Plesiochelys solodurensis, thereby tentatively confirming for the first time the monophyly of Plesiochelyidae using cladistic arguments. © 2014 Copyright Taylor & Francis Group, LLC.
Scherler L.,Section darcheologie et paleontologie |
Mennecart B.,University of Fribourg |
Hiard F.,University of Fribourg |
Becker D.,Musee jurassien des science naturelles
Swiss Journal of Geosciences | Year: 2013
The biostratigraphy and diversity patterns of terrestrial, hoofed mammals help to understand the transition between the Palaeogene and the Neogene in Western Europe. Three phases are highlighted: (1) the beginning of the Arvernian (Late Oligocene, MP25-27) was characterised by a "stable" faunal composition including the last occurrences of taxa inherited from the Grande Coupure and of newly emerged ones; (2) the latest Arvernian (Late Oligocene, MP28-30) and the Agenian (Early Miocene, MN1-2) saw gradual immigrations leading to progressive replacement of the Arvernian, hoofed mammals towards the establishment of the "classical" Agenian fauna; (3) the beginning of the Orleanian (Early Miocene, MN3-4) coincided with the African-Eurasian faunal interchanges of the Proboscidean Datum Events and led to complete renewal of the Agenian taxa and total disappearance of the last Oligocene survivors. Faunal balances, poly-cohorts and particularly cluster analyses emphasise these three periods and define a temporally well-framed Oligocene-Miocene transition between MP28 and MN2. This transition started in MP28 with a major immigration event, linked to the arrival in Europe of new ungulate taxa, notably a stem group of "Eupecora" and the small anthracothere Microbunodon. Due to its high significance in the reorganisation of European, hoofed-mammal communities, we propose to name it the Microbunodon Event. This first step was followed by a phase of extinctions (MP29-30) and later by a phase of regional speciation and diversification (MN1-2). The Oligocene-Miocene faunal transition ended right before the two-phased turnover linked to the Proboscidean Datum Events (MN3-4). Locomotion types of rhinocerotids and ruminants provide new data on the evolution of environments during the Oligocene-Miocene transition and help understand the factors controlling these different phases. Indeed, it appears that the faunal turnovers were primarily directed by migrations, whereas the Agenian transitional phase mainly witnessed speciations. © 2013 Swiss Geological Society.
Mennecart B.,University of Fribourg |
Becker D.,Section darcheologie et paleontologie |
Berger J.-P.,University of Fribourg
Swiss Journal of Geosciences | Year: 2011
The primitive ruminant genus Iberomeryx is poorly documented, as it is essentially only known from rare occurrences of dental remains. Therefore, the phylogeny and palaeobiology of Iberomeryx remain rather enigmatic. Only two species have been described: the type species I. parvus from the Benara locality in Georgia, and the Western European species I. minor reported from France, Spain, and Switzerland. Iberomeryx savagei from India has recently been placed in the new genus Nalameryx. All these localities are dated to the Rupelian and correspond mainly to MP23 (European mammal reference level). Based on the short height of the tooth-crown and the bunoselenodont pattern of the molars, Iberomeryx has often been considered as a folivore/frugivore. The I. minor remains from Soulce (NW Switzerland) are preserved in Rupelian lacustrine lithographic limestones. One specimen from this locality represents the most complete mandible of the taxon with a partially persevered ramus. Moreover, the unpreserved portion of the mandible left an imprint in the sediment, permitting the reconstruction of the mandible outline. Based on a new description of these specimens, anatomical comparisons and Relative Warp Analysis (24 landmarks) of 94 mandibles (11 fossil and 83 extant) from 31 ruminant genera (10 fossil and 21 extant) and 40 species (11 fossil and 29 extant), this study attempts a preliminary discussion of the phylogeny and the diet of the species I. minor. The results permit to differentiate Pecora and Tragulina on the first principal component axis (first Relative warp) on behalf of the length of the diastema c/cheek teeth, the length of the premolars and the angular process. The mandible shape of I. minor is similar to those of the primitive Tragulina, but it differs somewhat from those of the extant Tragulidae, the only extant family in the Tragulina. This difference is essentially due to a stockier mandible and a deeper incisura vasorum. However, in consideration of the general pattern of its cheek teeth, I. minor as well as possibly Nalameryx should be considered to represent the only known primitive Tragulidae from the Oligocene. Moreover, I. minor should have been a selective browser (fruit and dicot foliage) but, similarly to small Hypertragulidae and Tragulidae, may also have exceptionally consumed animal matter. © 2010 Swiss Geological Society.
Puntener C.,Section darcheologie et paleontologie |
Anquetin J.,Section darcheologie et paleontologie |
Billon-Bruyat J.-P.,Section darcheologie et paleontologie
PeerJ | Year: 2015
Background. The Swiss Jura Mountains are a key region for Late Jurassic eucryptodiran turtles. Already in the mid 19th century, the Solothurn Turtle Limestone (Solothurn, NW Switzerland) yielded a great amount of Kimmeridgian turtles that are traditionally referred to Plesiochelyidae, Thalassemydidae, and Eurysternidae. In the past few years, fossils of these coastal marine turtles were also abundantly discovered in the Kimmeridgian of the Porrentruy region (NW Switzerland). These findings include numerous sub-complete shells, out of which we present two new specimens of Thalassemys (Thalassemydidae) in this study. Methods. We compare the new material from Porrentruy to the type species Th. hugii, which is based on a well preserved specimen from the Solothurn Turtle Limestone (Solothurn, Switzerland). In order to improve our understanding of the paleogeographic distribution of Thalassemys, anatomical comparisons are extended to Thalassemys remains from other European countries, notably Germany and England. Results. While one of the two Thalassemys specimens from Porrentruy can be attributed to Th. hugii, the other specimen represents a new species, Th. bruntrutana n. sp. It differs from Th. hugii by several features: more elongated nuchal that strongly thickens anterolaterally; wider vertebral scales; proportionally longer plastron; broader and less inclined xiphiplastron; wider angle between scapular process and acromion process. Our results show that Th. hugii and Th. bruntrutana also occur simultaneously in the Kimmeridgian of Solothurn as well as in the Kimmeridgian of England (Kimmeridge Clay). This study is an important step towards a better understanding of the paleobiogeographic distribution of Late Jurassic turtles in Europe. © 2015 Püntener et al.
Anquetin J.,Section darcheologie et paleontologie
PeerJ | Year: 2015
Background. In a recent paper, we proposed a lectotype for the species Plesiochelys langii Rütimeyer, 1873. However, we failed to register this publication in ZooBank as required by the International Commission on Zoological Nomenclature (ICZN) for electronic publication. Although our conclusions remain unchanged, this particular nomenclatural act cannot be considered as published under ICZN regulations. Results. The present work fulfills the requirements of the ICZN for a lectotype designation and has been registered in ZooBank. © 2015 Anquetin.
Koppka J.,Section dArcheologie et Paleontologie
Zootaxa | Year: 2015
The current work is the first part of a taxonomic revision of the highly diverse Kimmeridgian bivalve fauna of the Reuchenette Formation of northwestern Switzerland (Canton Jura). It provides a taxonomic, paleoecologic and bibliographic review of the eight oyster species characterizing the northern Helvetic shelf: Circunula n. gen. cotyledon (Contejean, 1859) (Gryphaeidae, ?Pycnodonteinae), Nanogyra (Nanogyra) nana (J. Sowerby, 1822), Nanogyra (Palaeogyra) reniformis (Goldfuss, 1833), Nanogyra (Palaeogyra) virgula (Deshayes, 1831) (Gryphaeidae, Exogyrinae), Helvetostrea n. gen. sequana (Thurmann & Etallon, 1862) (Flemingostreidae, Crassostreinae), Praeexogyra dubiensis (Contejean, 1859), Praeexogyra monsbeliardensis (Contejean, 1859) (Flemingostreidae, Liostreinae), and Actinostreon gregareum (J. Sowerby, 1815) (Arctostreidae, Palaeolophinae). The paper proposes two new genera: Circunula and Helvetostrea. Palaeogyra Mirkamalov, 1963, is considered a subgenus of Nanogyra Beurlen, 1958. Lectotypes are designated for six species: C. cotyledon, Praeexogyra acuminata, P. dubiensis, P. monsbeliardensis, H. caprina, H. sequana. The figured types of H. oxfordiana (Rollier, 1917) and N. auricularis (Münster in Goldfuss, 1833) are considered holotypes by monotypy. All types are refigured in drawings and/or photographs. Early phases of shell ontogeny in general and the generic characters of Praeexogyra are revisited. Larval shells or their internal moulds are shown for six species: N. nana, N. reniformis, N. virgula, N. cf. auricularis, Praeexogyra cf. sandalinoides (de Loriol, 1901), and Actinostreon marshii (J. Sowerby, 1814). All of them are "Crassostrea"-like suggesting a planktic-planktotrophic mode of development. Circunula n. gen. shows a relatively high incidence of prosogyry (up to ca. 20% of studied specimens) during very early postlarval development. To a lesser extent, prosogyry has also been observed in species of Catinula, Praeexogyra and Pernostrea. Chomata are typical of early ontogenetic stages of Circunula n. gen., but they disappear during later growth stages. Circunula n. gen. cotyledon is a typical early settler on hardgrounds but occurs also in subtidal soft-bottom environments attached to large shells. Nanogyra (N.) nana attached itself to all kinds of biogenous hard and soft substrates including algal stems and thalli. It is regularly found in calm to moderately energetic shallow marine paleoenvironments. Nanogyra (P.) reniformis frequently settled on the interior of empty bivalve shells. Nanogyra (P.) virgula was esentially a secondary soft-bottom dweller of shallow marine marls and lime muds. The species is often found concentrated in widely distributed (par)autochthonous lumachelles ("virgula marls" of authors) in the Upper Oxfordian, Upper Kimmeridgian and Tithonian. Praeexogyra dubiensis and P. monsbeliardensis occur in marly, shallow marine paleoenvironments. Praeexogyra dubiensis appears to have preferred attachment to small objects in a moderately energetic facies. In the study area it is also associated with algal meadows. Praeexogyra monsbeliardensis was preferentially gregarious in somewhat deeper and calmer paleoenvironments. The strongly chambered and probably fast growing Helvetostrea n. gen. sequana was adapted to moderate to high energetic shallow marine, marly habitats. It is frequently associated with corals and forms ostreoliths or small oyster buildups. Actinostreon gregareum usually lived gregariously but was also able to attach itself to algae on soft substrates. The species is known from calm marly to higher energetic coralline paleoenvironments. © 2015 Magnolia Press.