Search results for "MAC"
showing 10 items of 24950 documents
A large temnospondyl humerus from the Rhaetian (Late Triassic) of Bonenburg (Westphalia, Germany) and its implications for temnospondyl extinction
2018
Temnospondyls are a group of basal tetrapods that existed from the Early Carboniferous to the Early Cretaceous. They were characteristic members of Permian and Triassic continental faunas around the globe. Only one clade, the Brachyopoidea (Brachyopidae and Chigutisauridae), is found as relics in the Jurassic of eastern Asia and the Cretaceous of Australia. The other Late Triassic clades, such as Plagiosauridae, Metoposauridae, and Cyclotsauridae, are generally believed to have gone extinct gradually before the end of the Triassic and putative Rhaetian records are stratigraphically poorly constrained. Temnospondyl humeri all show a similar morphological pattern, being stout, short, with wid…
Rich fen development in CE Europe, resilience to climate change and human impact over the last ca. 3500 years
2017
Here, for the first time in SE Poland, we document the long-term development of a rich fen and assess its sensitivity to climate change and human impacts over the last ca. 3500 years. Our results are based on a high-resolution, continuous plant macrofossil remains, mollusc and pollen record, complemented by geochemical, mineral magnetic and physical characterisation, and radiocarbon dating from Bagno Serebryskie rich fen located in SE Poland. Based on the palaeoecological data we distinguished five stages of wet habitat conditions: 5000–3300, 2800–2150, 1600–1100, 750–230, 150–10 cal yr BP and five dry periods at ca. 3300–2800, 2150–1600, 1100–750, 230–150, 10 to − 64 cal yr BP. The pollen …
New Permian tetrapod footprints and macroflora from Turkey (Çakraz Formation, northwestern Anatolia): biostratigraphic and palaeoenvironmental implic…
2011
9 pages; International audience; New tetrapod footprints belonging to the ichnogenus Hyloidichnus have been discovered in Turkey for the first time, in the lower part of the Çakraz Formation (Northwestern Anatolia) and together with macrofloral imprints of Annularia and Stigmaria. These discoveries confirm the Permian age of the fossiliferous red beds in which the coniferophyte Walchia was previously recorded. Based on the stratigraphic range of Annularia, Stigmaria and Hyloidichnus known elsewhere, a Cisuralian age is proposed for these beds. These new ichno- and macrofloral remains, together with the sedimentological data (mudcracks, rain drops) suggest the presence of captorhinid reptile…
La tombe à chars d'Évergnicourt (Aisne), "Le Tournant du Chêne"
2005
Lambot Bernard, Méniel Patrice. La tombe à chars d'Évergnicourt (Aisne), "Le Tournant du Chêne". In: Revue archéologique de Picardie. Numéro spécial 22, 2005. Hommages à Claudine Pommepuy. pp. 327-354.
Economic modelling as a tool to support macroalgal bloom management: a case study (Sacca di Goro, Po river delta)
2003
During the last 20, years, intensive mollusk farming has been developed in coastal waters, mostly in sheltered bays and lagoons. Often, mollusk stocks are threatened by frequent anoxic events from macroalgal blooms. Here, a decision support tool is described to select the optimal short-term strategy to control algal biomasses. Even though long-term and detailed studies of the lagoon systems are required to provide reliable, biologically based policies, we have here developed a simplified analysis that overlooks most of the ecological complexity, but explicitly includes environmental variability and uncertainty in parameter estimation in the economic assessment of the performances of differe…
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…
Allometric space and allometric disparity: a developmental perspective in the macroevolutionary analysis of morphological disparity.
2008
8 pages; International audience; Here, we advance novel uses of allometric spaces--multidimensional spaces specifically defined by allometric coefficients--with the goal of investigating the focal role of development in shaping the evolution of morphological disparity. From their examination, operational measures of allometric disparity can be derived, complementing standard signals of morphological disparity through an intuitive and process-oriented refinement of established analytical protocols used in disparity studies. Allometric spaces thereby become a promising context to reveal different patterns of evolutionary developmental changes and to assess their relative prevalence and import…
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…
Evidence of endothermy in the extinct macropredatory osteichthyan Xiphactinus audax (Teleostei, Ichthyodectiformes)
2020
Xiphactinus audax is the largest macropredatory osteichthyan ever known (Everhart et al., 2010). Some of the largest specimens exceed 5 m in total length, although the discovery of a few large, isolated teeth suggests that this teleost could reach even larger body sizes (Vavrek et al., 2016, and references therein). Fossil remains of this species have only been reported from the Upper Cretaceous of North America, across the Western Interior Basin (Schwimmer et al., 1997; Vavrek et al., 2016). The discovery of several virtually complete individuals in this area has provided valuable information about the anatomy, the dimensions, and the ecology of this species (Cope, 1872; Bardack, 1965). Xi…
Systematic revision of the Late Miocene sabre-toothed felid Paramachaerodus in Spain
2010
Abstract: A systematic revision of the sabre-toothed cat genus Paramachaerodus Pilgrim, 1913 is presented. Two species are recognized within Paramachaerodus, Pa. orientalis, and Pa. maximiliani, and the genus Promegantereon Kretzoi, 1938 is retrieved to include Promegantereon ogygia. Material from the Turolian Spanish localities of Crevillente-2 (MN 11, Alicante) and Las Casiones (MN 13, Teruel), which was previously assigned to Paramachaerodus, is now included in the tribe Metailurini. The exceptional discoveries at the Spanish Vallesian (MN 10, Madrid) fossil site of Batallones-1 have made it possible to characterize the dentition and cranial anatomy of a previously very poorly known mac…