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showing 10 items of 57859 documents
Biodiversity is not (and never has been) a bed of roses!
2011
9 pages; International audience; Over the last decades, the critical study of fossil diversity has led to significant advances in the knowledge of global macroevolutionary patterns of biodiversity. The deep-time history of life on Earth results from background originations and extinctions defining a steady-state, nonstationary equilibrium occasionally perturbed by biotic crises and "explosive" diversifications. More recently, a macroecological approach to the large-scale distribution of extant biodiversity offered new, stimulating perspectives on old theoretical questions and current practical problems in conservation biology. However, time and space are practically distinct, but functional…
New Bovid Remains from the Early Pleistocene of Umbria (Italy) and a Reappraisal of Leptobos merlai
2017
The extinct bovid Leptobos is one of the most characteristic elements of Eurasian faunal assemblages during most of the Villafranchian Land Mammal Age (i.e., from the late Pliocene to most of the early Pleistocene). Several species of this genus have been established since the end of XIX Century, but their taxonomic status and phylogenetic relationships remain unclear due to the fact that most of them are described on the basis of scanty material. European species are divided into two groups or lineages. The first includes L. stenometopon, L. merlai, and the poorly known L. furtivus, the second L. etruscus and L. vallisarni. While the last two species are well documented in the Italian earl…
Categorical versus geometric morphometric approaches to characterizing the evolution of morphological disparity in Osteostraci (Vertebrata, stem Gnat…
2020
Morphological variation (disparity) tends to be evaluated through two non-mutually exclusive approaches: (i) quantitatively, through geometric morphometrics, and (ii) in terms of discrete, ‘cladistic’, or categorical characters. Uncertainty over the comparability of these approaches diminishes the potential to obtain nomothetic insights into the evolution of morphological disparity, and the few benchmarking studies conducted so far show contrasting results. Here, we apply both approaches to characterising morphology in the stem-gnathostome vertebrate clade Osteostraci, in order to assess congruence between these alternative methods as well as to explore the evolutionary patterns of the grou…
Étude paléobotanique d’une lentille argileuse cénomanienne de la carrière de Hucheloup, Maine-et-Loire, NO France : implications taxonomiques, strati…
2017
International audience; A Cenomanian clay lens in Hucheloup Quarry (Maine-et-Loire, north-western France) has yielded 82 foliar compressions and impressions, of which 62 were identified at several taxonomic levels. The plants are ascribed to diverse Pinales (27%), ferns (27%), Ginkgoales (26%), angiosperms (19%) and Cycadales (1%). The most abundant species in the assemblage are Frenelopsis alata (K. Feistmantel) E. Knobloch emend. J. Kvaček (Pinales) and Eretmophyllum obtusum (Velenovský) J. Kvaček (syn. E. andegavense Pons, Bourreau et Broutin) (Ginkgoales). Wood fragments, along with very well-preserved cuticles, have also been recovered and identified. The specimens are usually very fra…
Macrofossil evidence of Late Holocene presence of Aldrovanda vesiculosa L. in Central-Eastern Europe (Poland) and East Africa (Tanzania)
2015
International audience; To date, the seeds of waterwheel plant (Aldrovanda vesiculosa) were only found in Europe, in sediments of the Eemian and Mazovian Interglacials. The absence of A. vesiculosa seeds in European Holocene deposits is probably due to unfavorable climatic conditions, i.e. lower temperature, during this period: in temperate zones, A. vesiculosa reproduces mainly in a vegetative way; it rarely blooms and only occasionally produces seeds. In this paper, subfossil seeds of A. vesiculosa were identified in two peat bogs: one (Sucha Kobyła) in SE Poland and another one (Kyambangunguru) in SW Tanzania. Single seeds of this plant were found in a peat layer from the Polish site for…
New data on bat fossils from Middle and Upper Pleistocene localities of France
2011
We describe the bat fossils preserved in four sites from the middle and upper Pleistocene, three of them being well-known French localities: the rock shelter of Les Valerots, the caves of l’Escale at Saint Estève Janson and ‘‘du Prince’’ at Grimaldi (Italy), and the filling of Combe-Grenal, all of them containing microvertebrate assemblages with yet undescribed bat fossils. All species represented in these four localities are still presently distributed in France and had been previously recorded in other Pleistocene localities of central and western Europe, including France. The four assemblages differ both in the abundance of bat fossils as in species composition. The characteristics of ea…
Nomenclatural revision concerning some genera of the Order Trigoniida (Bivalvia)
2018
The authors have become aware of a couple of nomenclatural conflicts involving Mesozoic trigoniid genera, which are in need of clarification and proposal of replacement names: The case of Protrigonia. The subgenus Trigonia (Protrigonia) Guo, 1985 (p. 204, 269; type species Trigonia (Protrigonia) yunnanensis Guo, 1985), was proposed to encompass those species referred to the genus Trigonia which, according to that author, have small and nearly smooth shells and relatively weak teeth. Guo (1985) also included other Triassic species: Trigonia gaytani (von Klipstein, 1843) and Trigonia zlambachiensis Haas, 1909. According to Fang et al. (2009, p. 55) there was a wrong translation from the Chine…
Le site à ambre et plantes du Cénomanien de Neau (Mayenne, France)
2020
International audience; A new Cenomanian amber- and plant-bearing deposit has been discovered at Neau, in the Mayenne department (France). The Cenomanian fossiliferous lignites are located in karst filling in a substratum of Cambrian limestones. The amber corresponds mainly to tiny millimetric grains, devoid of arthropod inclusions, but rich in microorganisms, especially the sheated bacteria Leptotrichites resinatus , and containing pollen grains ( Classopollis ) and wood fibers (Araucariacae or Cheirolepidiaceae). The lignites provide abundant conifer and ginkgoale cuticle fragments ( Frenelopsis , Eretmophyllum ) and a lot of palynomorphs ( e.g. Gleicheniidites senonicu s, Cyathidites , D…
Development of Rich Fen on the SE Baltic Coast, Latvia, during the Last 7500 Years, Using Paleoecological Proxies: Implications for Plant Community D…
2016
We present the paleoecological development of a rich fen located in the dune area on the SE Baltic coast, during the last 7500 years. The Apsuciems Mire hosts rare and endangered plant communities in Europe, such as Schoenus ferrugineus and Cladium mariscus. Analysis at high-resolution of plant macroremains in two peat cores was carried out to reconstruct local vegetation succession and fluctuations in moisture availability on the peatland, while a pollen record was developed to reconstruct plant succession, moisture variability and human activity at the regional scale. Based on the presence or the absence of macroremains of plants that occur in wet habitat e.g. Cladium mariscus, Schoenople…
Does quality of winter food affect spring condition and breeding in female bank voles (Clethrionomys glareolus)?
2004
We studied the effects of food supplementation on 16 bank vole populations in spring. We manipulated food quantity and quality in eight populations that were enclosed and eight other populations th...