Browsing by Subject "paleontology"

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  • Muona, Jyrki (2020)
    Eight new genera and twenty new species of Eucnemidae are described from Cretaceous Myanmar amber: Cupressicharis n. gen. (type-species Cupressicharis elongatus n. sp.), Cylus n. gen. (type species Cylus carinifer n. sp.), Falsothambus n. gen. (type species Falsothambus burmensis n. sp.). Fiegelia n. gen. (type species Fiegelia antennata n. sp.), Paleoeucnemis n. gen. (type species Paleoeucnemis minutus n. sp.), Protomicrorhagus n. gen. (type species Protomicrorhagus antennatus n. sp.), Protovitellius n. gen. (type species Protovitellius deceptus n. sp,) and Pseudomyall n. gen. (type species Pseudomyall elongatulus n. sp). Eleven further species are described: Coenomana brevicornis n. sp., Euryptychus acutangulus n. sp., Euryptychus burmensis n. sp, Euryptychus elegantulus n. sp., Euryptychus mysticus n. sp, Epiphanis burmensis n. sp., Falsothambus gracilicornis n. sp., Fiegelia tarsalis n. sp., Jenibuntor pusillus n. sp., Myall burmensis n. sp., Protomicrorhagus brevis n. sp, Sieglindea antiqua n. sp. Coenomana clavata Otto is transferred from tribe Jenibuntorini to tribe Dirhagini. Muonabuntor grandinotalis Li , Tihelka & Cai is transferred from tribe Jenibuntorini to tribe Euryptychini.
  • Pushkina, Diana (Helsingfors universitet, 2007)
    Short and long term environmental changes, variations in climate and vegetation during the late Neogene shaped the geographical ranges of large terrestrial mammals by allowing origination, distribution and dispersal of certain species that make up faunas. Climatic fluctuations were intensified during the latest Neogene, Pleistocene (1.8-0.01 Ma), at the end of which also human presence became more conspicuous. Both climate and humans have been linked to extensive alteration and extinctions in mammalian faunas across the world. This dissertation consists of a set of papers that examine different periods of the Neogene and associated faunas in northern Eurasia. Major trends in changing environments and climate were studied by means of the tooth crown height (hypsodonty) and dietary structure in herbivorous terrestrial mammals or/and species commonness (locality coverage, abundance proxy). This study was also intended to bring to light a great deal of information contained in Russian literature to fill in the gap between the European literature and not translated Russian records. Since the middle Miocene (~15-11 Ma), central Asia has been the focal point of the transformation in Eurasia towards more open and dry environment. The drying of the central part of Eurasia hampered the spread of temperate or mesophilic species between western and eastern sides of the continent, and created conditions for origination of the cold and arid adapted grazing fauna in north-eastern Eurasia. Throughout the climatically unstable late middle and late Pleistocene, Europe that was more maritime during interglacials than Siberia, experienced the most drastic faunal alternations between the interglacial Palaeoloxodon antiquus and glacial Mammuthus primigenius assemblages that permanently inhabited the Mediterranean and Siberia, respectively. During more climatically equable middle part of the middle Pleistocene (Holsteinian interglacial) that was climatically similar to the current Holocene, the interglacial species could have spread eastwards. The origins, dispersal and cohesiveness of the Palaeoloxodon antiquus assemblage in Eurasia are examined. During the latest Weichselian Glaciation (Late Glacial, 15 000-10 500 yr BP, latest late Paleolithic) and Holocene (last 10 000 yr) a rapid warming initiated fragmentation of dry and cold tundra-steppes when increased temperature and humidity produced boggy tundra in the north and forests in the south of the most part of northern Eurasia. The most significant change took place in central Asia influencing the glacial mammoth fauna decline as is seen in southern Siberia from decreased mean hypsodonty and the shift in dietary preferences from grazing towards browsing in herbivorous ungulates along with decreased mean body size in large mammals. It is difficult to disentangle the role of humans from climate effect in large mammal extinctions in Eurasia at the Weichselian-Holocene boundary because they pretty much coincided. The study is consistent with the idea that Eurasian late Pleistocene extinctions were first climatically driven, after which the impact of rapidly expanding humans must have become more manifest and crucial either by direct hunting or via indirect activities. Only the data for the extinct steppe bison may indicate a disproportionate selection by humans although more sufficient and recently updated data are needed. Key words: Pleistocene, Neogene, Paleolithic, interglacial, glacial, large mammals, distribution, hypsodonty, aridity, precipitation, body size, commonness, extinction, human influence.
  • Fraser, Danielle; Soul, Laura C.; Tóth, Anikó B.; Balk, Meghan A.; Eronen, Jussi T.; Pineda-Munoz, Silvia; Shupinski, Alexandria B.; Villaseñor, Amelia; Barr, W. Andrew; Behrensmeyer, Anna K.; Du, Andrew; Faith, J. Tyler; Gotelli, Nicholas J.; Graves, Gary R.; Jukar, Advait M.; Looy, Cindy V.; Miller, Joshua H.; Potts, Richard; Lyons, S. Kathleen (2021)
    Recent renewed interest in using fossil data to understand how biotic interactions have shaped the evolution of life is challenging the widely held assumption that long-term climate changes are the primary drivers of biodiversity change. New approaches go beyond traditional richness and co-occurrence studies to explicitly model biotic interactions using data on fossil and modern biodiversity. Important developments in three primary areas of research include analysis of (i) macroevolutionary rates, (ii) the impacts of and recovery from extinction events, and (iii) how humans (Homo sapiens) affected interactions among non-human species. We present multiple lines of evidence for an important and measurable role of biotic interactions in shaping the evolution of communities and lineages on long timescales.
  • Muona, Jyrki (2022)
    One new genus and three new false click-beetle species (Coleoptera: Eucnemidae) are described from American fossil resins: Neusiokia new genus, type species Neusiokia appalachiensis new species (North Carolina resin), Thambus woodruffi new species (Dominican resin) and Asiocnemis colombicus new species (Colombian resin). Seventy-two fossil species are included in the family Eucnemidae presently. Half of them, 36, are based on Baltic amber materials (Muona 1993a; Muona 2021), 22 are from Myanmar amber deposits (Li et al. 2020; Muona 2020; Otto 2019) and 10 are mineral fossils, nine of these from China (Chang et al. 2016; Muona et al. 2020; Li et al. 2021) and one from Australia (Oberprieler et al. 2016). The remaining four valid fossil eucnemid species have been described from the Americas, one from Dominican amber (Poinar 2012) and three from the Florissant beds (Wickham 1916). The purpose of the present work is to describe three new American fossil species from different types of resins.
  • Muona, Jyrki (2022)
    One new genus and three new false click-beetle species (Coleoptera: Eucnemidae) are described from American fossil resins: Neusiokia new genus, type species Neusiokia appalachiensis new species (North Carolina resin), Thambus woodruffi new species (Dominican resin) and Asiocnemis colombicus new species (Colombian resin). Seventy-two fossil species are included in the family Eucnemidae presently. Half of them, 36, are based on Baltic amber materials (Muona 1993a; Muona 2021), 22 are from Myanmar amber deposits (Li et al. 2020; Muona 2020; Otto 2019) and 10 are mineral fossils, nine of these from China (Chang et al. 2016; Muona et al. 2020; Li et al. 2021) and one from Australia (Oberprieler et al. 2016). The remaining four valid fossil eucnemid species have been described from the Americas, one from Dominican amber (Poinar 2012) and three from the Florissant beds (Wickham 1916). The purpose of the present work is to describe three new American fossil species from different types of resins.