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''Nanantius eos''〔 Etymology: "Dawn Dwarf-enantiornithine". ''Nanantius'', "dwarf enantiornithine", from Ancient Greek ''nan-'', "dwarf-" + ''(en)antos'', "opposite". ''eos'', Ancient Greek for "dawn".〕 is the name of an Early Cretaceous (Albian, c. 100-112 mya) species of bird. It is the only described member of the genus ''Nanantius'' at present; the supposed second species ''Nanantius valifanovi'' has turned out to be a synonym of ''Gobipteryx minuta''. ''N. eos'' is known from two incomplete tibiotarsi from the Toolebuc Formation stratum, the first (Queensland Museum F12992) found at Warra Station near Boulia, in Queensland (Australia). Other remains from Australia have also been placed into the genus ''Nanantius'' but not assigned to a species. Furthermore, there are some bones from the Late Cretaceous, found in the Bissekty Formation of the Kyzyl Kum desert, Uzbekistan, which belong either into ''Nanantius'' or a closely related genus; however, due to the date difference, they are almost certainly not ''N. eos'' in any case. Initially, ''Nanantius eos'' was classified as an enanthiornithine, a Cretaceous group of primitive birds that did not survive the Cretaceous–Paleogene mass extinction. However, it is now known that the characters of the tibiotarsus are not sufficiently diagnostic to place a bird into the Enantiornithes. For example, the more modern genus ''Apsaravis'' also possessed an "enantiornithine" tibiotarsus (Clarke & Norell, 2002). Thus, although an enantiornithine affinity of ''Nanantius'' is likely - these birds were the dominant avian group in the Early Cretaceous, and the tibiotarsus is very similar to the doubtlessly enantiornithine ''Gobipteryx'' -, this placement is not certain until more diagnostic material, such as the characteristic tarsometatarsi, have been found. ''N. eos'' was a small species, about the size of a Blackbird; it probably looked like a miniature gull with clawed wings and a neck and head more similar to a feathered theropod dinosaur, but with a beak. It is assumed to have fed on marine invertebrates and small fish; certainly, it lived on the coast of what was then the Eromanga Sea, a shallow subtropical arm of the Tethys Seaway. That ''Nanantius'' were seabirds is evidenced by the fact that another tibiotarsus referrable to this genus, and quite possibly to ''N. eos'' itself, was found in the gut of an ichthyosaur (Kear ''et al.'', 2003). ==In popular culture== ''Nanantius'' makes a brief appearance in the companion book to the series ''Walking with Dinosaurs''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nanantius」の詳細全文を読む スポンサード リンク
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