Search results for "FOSS"
showing 10 items of 556 documents
Ornamentation of dermal bones of Metoposaurus krasiejowensis and its ecological implications
2018
Background Amphibians are animals strongly dependent on environmental conditions, like temperature, water accessibility, and the trophic state of the reservoirs. Thus, they can be used in modern palaeoenvironmental analysis, reflecting ecological condition of the biotope. Methods To analyse the observed diversity in the temnospondyl Metoposaurus krasiejowensis from Late Triassic deposits in Krasiejów (Opole Voivodeship, Poland), the characteristics of the ornamentation (such as grooves, ridges, tubercules) of 25 clavicles and 13 skulls were observed on macro- and microscales, including the use of a scanning electron microscope for high magnification. The different ornamentation patterns fo…
Regional endothermy as a trigger for gigantism in some extinct macropredatory sharks
2017
Otodontids include some of the largest macropredatory sharks that ever lived, the most extreme case being Otodus (Megaselachus) megalodon. The reasons underlying their gigantism, distribution patterns and extinction have been classically linked with climatic factors and the evolution, radiation and migrations of cetaceans during the Paleogene. However, most of these previous proposals are based on the idea of otodontids as ectothermic sharks regardless of the ecological, energetic and body size constraints that this implies. Interestingly, a few recent studies have suggested the possible existence of endothermy in these sharks thus opening the door to a series of new interpretations. Accord…
Introducing anatomical techniques to subfossil wood
2018
Abstract Successful cross-dating of subfossil wood, ideally in combination with precise information on germination and dieback, requires the accurate detection of tree-ring width (TRW) boundaries along continuous measurement tracks from pith to bark. However, wood decay and the mechanical deformation of cells often challenge the dendrochronological analysis and subsequent paleoclimatic and environmental interpretations. Here, we show that wood anatomical techniques can improve the assessment of heavily degraded and/or deformed material. We apply state-of-the-art sample preparation, thin sectioning and double-staining to a unique collection of Late Glacial pines that were growing ∼13,000 yea…
Biogeography of Triassic ammonoids
2015
After the end-Permian mass extinction, ammonoids experienced an explosive recovery followed by episodes of radiation and extinction. These events were associated with sudden biogeographic changes often closely related to major climatic and oceanographic changes. Previous biogeographic studies of Triassic ammonoids have rarely focused on a specific time-interval and were rarely based on quantitative methods. Thus, we will first review biogeographical methods and the biogeographical signals known from Triassic ammonoids. Secondly, we will focus on quantitative approaches that improve our knowledge of ammonoid biogeographical structuring and dynamics during the Triassic, and we will discuss co…
Carnivore stable carbon isotope niches reflect predator-prey size relationships in African savannas.
2017
Predator-prey size relationships are among the most important patterns underlying the structure and function of ecological communities. Indeed, these relationships have already been shown to be important for understanding patterns of macroevolution and differential extinction in the terrestrial vertebrate fossil record. Stable isotope analysis (SIA) is a powerful remote approach to examining animal diets and paleodiets. The approach is based on the principle that isotope compositions of consumer tissues reflect those of their prey. In systems where resource isotope compositions are distributed along a body size gradient, SIA could be used to reconstruct predator-prey size relationships. We …
New Hettangian tracks from the Causses Basin (Lozère, southern France) complement the poor fossil record of earliest Jurassic crocodylomorphs in Euro…
2017
International audience; A new vertebrate ichnological assemblage is described from the Hettangian Dolomitic Formation of the Causses Basin, at Le Serre (Lozère, southern France). We report tracks that complement the poor fossil record of lowermost Jurassic crocodylomorphs in Europe. Tetradactyl pes and pentadactyl manus imprints form a unique trackway. Traces are ascribed to Batrachopus isp. and they represent the third occurrence of this ichnogenus in European Hettangian geological formations. This is the first report of Batrachopus in Hettangian deposits of the Causses Basin. The tracks share some similarities with Batrachopus deweyi previously described from the Sinemurian of the Causses…
The evolution of palate shape in the Lepilemur‐Cheirogaleidae clade (Primates: Strepsirrhini).
2020
15 pages; International audience; Objectives: Phylogenies consistently group the folivorous Lepilemur species with the small-bodied insectivorous-frugivorous cheirogaleids. Juvenile lepilemurs and adult cheirogaleids share allometries in most aspects of skull morphology, except the palate. We investigated potential influences on palate shape in these taxa and several outgroups using geometric morphometrics.Materials and methods: Our sample included representatives of four extant strepsirrhine families, Cheirogaleidae (including Lepilemurinae), Lemuridae, Indriidae, and Galagidae, and one subfossil Megaladapis. Our dataset comprised 32 landmarks collected from 397 specimens representing 15 g…
Grapes and vines of the Phoenicians: morphometric analyses of pips from modern varieties and Iron Age archaeological sites in the Western Mediterrane…
2021
The present study aims to contribute to the investigation of the role of Phoenicians in the spreading and trade of the grapevine through the morphometric analysis of grape pips. Waterlogged and charred samples were selected from three Iron Age sites in the Western Mediterranean: Motya (Sicily, Italy), Nuraghe S’Urachi (Sardinia, Italy) and Huelva (Andalusia, Spain). While only Motya is a Phoenician foundation, all three were nevertheless associated with Phoenician expansion and cultural interaction. Ten cultivars from the “Vivaio Federico Paulsen” in Marsala (western Sicily) were chosen as modern reference material. The key challenge was the comparison of archaeological pips preserved throu…
Evolution of mammal tooth patterns: new insights from a developmental prediction model.
2009
14 pages.; International audience; The study of mammalian evolution is often based on insights into the evolution of teeth. Developmental studies may attempt to address the mechanisms that guide evolutionary changes. One example is the new developmental model proposed by Kavanagh et al. (2007), which provides a high-level testable model to predict mammalian tooth evolution. It is constructed on an inhibitory cascade model based on a dynamic balance of activators and inhibitors, regulating differences in molar size along the lower dental row. Nevertheless, molar sizes in some mammals differ from this inhibitory cascade model, in particular in voles. The aim of this study is to point out arvi…
Going underground: short- and long-term movements may reveal the fossorial spatial ecology of an amphisbaenian
2021
[Background]: The movement and spatial ecology of an animal depends on its morphological and functional adaptations to its environment. In fossorial animals, adaptations to the underground life help to face peculiar ecological challenges, very different from those of epigeal species, but may constrain their movement ability.