Search results for "Llum"
showing 10 items of 570 documents
Lowermost Jurassic dinosaur ecosystem from the Bleymard Strait (southern France): sedimentology, mineralogy, palaeobotany and palaeoichnology of the …
2021
AbstractWe report the first Hettangian theropod tracksite (~200 Ma) yielding a rich accumulation of plant remains from the Bleymard Strait (southern France). It constitutes an excellent opportunity to reconstruct lowermost Jurassic ecosystems hosting dinosaurs and which are still poorly documented in this area. Two morphotypes of tridactyl tracks are distinguished. They share similarities with Grallator and Kayentapus. Plant-bearing beds yield abundant leafy axes (Pagiophyllum peregrinum), male cones (Classostrobus sp.), wood (Brachyoxylon sp.) and pollen of conifers (Classopollis classoides). Sedimentological, petrological and mineralogical analyses demonstrated that, in the Dolomitic Form…
Terrestrial plants and marine algae from the Late Jurassic lithographic limestone of the Causse Méjean (Lozère, southern France)
2016
International audience; A new Late Jurassic flora was discovered in the fossiliferous lithographic limestone of the Causse Méjean, Lozère (southern France). It consists of the first Kimmeridgian/Tithonian plants from this area. Fossil plants are represented by megaremains preserved as impressions. This flora shows a co-occurrence of terrestrial plants and marine algae. The land plants include vegetative remains ascribed to bennettitaleans (Zamites Brongniart, 1828), conifers (Brachyphyllum Brongniart, 1828), and pteridosperms (Cycadopteris Zigno, 1853). Marine algae were ascribed to dasyclads (Goniolina D’Orbigny, 1850). Lithological and palaeontological features suggest preservation in a f…
A combination of dichogamy and herkogamy mediates reproductive success in the desert shrub Zygophyllum fabago
2020
Abstract Zygophyllum fabago is a species within the arid-adapted family Zygophyllaceae. The species is characterized by the co-occurrence of dichogamy and herkogamy. In order to understand the effect of these two complementary anti-selfing mechanisms in reproductive success, we conducted a detailed study of floral biology in Z. fabago. Our results indicated an incomplete separation of the female and male phases which is referred to as partial dichogamy. We found two floral morphs with distinct stigma position: the Central-morph (C-morph) and the Lateral-morph (L-morph). The stigma-stamen distance in the L-morph was significantly larger than in the C-morph in early, mid, and late male stages…
Flore turonienne des silex fossilifères de Châtellerault (Ouest de la France)
2018
International audience; Three new localities yielding fossiliferous flints are reported from the Châtellerault area (Vienne, western France). They include one archaeological site (La Grande Vallée) and two zones with alterite deposits (L’Aunas and Les Bariollières). Broken surfaces of flint nodules show co-occurrence of marine invertebrates such as bryozoans, echinoids (Micraster Agassiz, Orthopsis Cotteau), gastropods (Acteonella d’Orbigny), rudists, and sponges. The association of Acteonella, Micraster and Orthopsis confirms the Turonian age (Upper Cretaceous) of the fossil assemblage. The marine invertebrates co-occur with plant macroremains including fragments of conifer leafy axes such…
Conifers from the Cenomanian amber of Fouras (Charente-Maritime, western France)
2020
Fossil inclusions of arthropods and microorganisms are abundant in the Cretaceous amber from western France, but plant meso- or macroremains are scarce. Preserved remains are mostly tiny, very fragmented, and indeterminable. Only one amber locality in the Charente department has already provided conifer remains. Here, we report the first plant mesoremains ensnared in Cenomanian amber from Fouras – Bois Vert, in the Charente-Maritime department. They consist of three well-preserved leafy axes and one cone of Cheirolepidiacean conifers. Based on the helical arrangement of rhomboidal, longer than wide, and highly adpressed leaves, leafy axes are ascribed to the genus Pagiophyllum. The ovoid co…
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…
The Bias of combining variables on fish's aggressive behavior studies.
2019
Made available in DSpace on 2019-10-06T16:27:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-01 Quantifying animal aggressive behavior by behavioral units, either displays or attacks, is a common practice in animal behavior studies. However, this practice can generate a bias in data analysis, especially when the variables have different temporal patterns. This study aims to use Bayesian Hierarchical Linear Models (B-HLMs) to analyze the feasibility of pooling the aggressive behavior variables of four cichlids species. Additionally, this paper discusses the feasibility of combining variables by examining the usage of different sample sizes and family distributions to aggressive …
Evolution of leaf anatomy in arid environments – A case study in southern African Tetraena and Roepera (Zygophyllaceae)
2015
The dry biomes of southern Africa (Desert, Nama Karoo and Succulent Karoo) are home to a rich and diverse xerophytic flora. This flora includes two morphologically diverse clades of Zygophyllaceae, Tetraena and Roepera (Zygophylloideae), which inhabit some of the most arid habitats in the region. Using a plastid phylogeny of Zygophylloideae we assess whether the evolution of putatively adaptive traits (leaf shape, vasculature, mode of water storage and photosynthetic type: C3 versus C4) coincides with the successful colonisation of environments with different drought regimes within southern Africa. Our results show general niche conservatism within arid habitats in Tetraena, but niche shift…
The plasticity of breeding system in arid-adapted Zygophylloideae
2019
Abstract The assurance of reproductive success is an important challenge for arid-adapted plants. Self-compatibility is suggested as a mechanism to compensate for the inadequate breeding opportunities in extreme environments. Zygophylloideae is an arid-adapted subfamily which has successfully radiated in different ranges of arid habitats. In order to study the significance of selfing for the reproductive success of the Zygophylloideae, we calculated pollen ovule ratios (P/O) and conducted bagging experiments for autogamy and xenogamy in eleven representative members of Zygophylloideae and three species of the sister subfamilies Tribuloideae and Larreoideae. Our results revealed an extremely…
Notulae to the Italian native vascular flora: 5
2018
In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records and confirmations to the Italian administrative regions for taxa in the genera Allium, Arabis, Campanula, Centaurea, Chaerophyllum, Crocus, Dactylis, Dianthus, Festuca, Galanthus, Helianthemum, Lysimachia, Milium, Pteris, and Quercus. Nomenclature and distribution updates, published elsewhere, and corrections are provided as supplementary material.