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''Ypresiomyrma'' is an extinct genus of ants in the subfamily Myrmeciinae that was described in 2006. There are four species described; one species is from the Isle of Fur in Denmark, two are from the McAbee Fossil Beds in British Columbia, Canada, and the fourth from the Bol’shaya Svetlovodnaya fossil site in Russia. The queens of this genus are large, the mandibles are elongated and the eyes are well developed; a stinger is also present. The behaviour of these ants would have been similar to that of extant Myrmeciinae ants, such as solitary foraging for arthropod prey and never leaving pheromone trails. The alates were poor flyers due to their size, and birds and animals most likely preyed on these ants. ''Ypresiomyrma'' is not assigned to any tribe, and is instead generally regarded as ''incertae sedis'' within Myrmeciinae. However, some authors believe ''Ypresiomyrma'' should be assigned as ''incertae sedis'' within Formicidae. ==History and classification== Fossils of ''Ypresiomyrma'' were first studied and described by Bruce Archibald, Stefan Cover and Corrie Moreau of the Museum of Comparative Zoology in Cambridge, Massachusetts. They published their 2006 description of the genus and species in an ''Annals of the Entomological Society of America'' journal article. The genus name is a combination of Ypresian, referring to the age of the specimens and the Greek ', meaning "ant". The minimum fossil age is approximately 54.5 to 55.5 million years. Along with the genus description, the paper contained descriptions of the type species ''Ypresiomyrma orbiculata'' and ''Ypresiomyrma bartletti'', both from the McAbee Fossil Beds in British Columbia, part of the Eocene Okanagan Highlands lake system. Archibald, Cover and Moreau also included a redescription of the Danish species ''Pachycondyla rebekkae'' under the new name combination ''Ypresiomyrma rebekkae''. A fourth species, ''Ypresiomyrma orientalis'' was described in 2015. Archibald and colleagues originally classified ''Ypresiomyrma'' as ''incertae sedis'' (Latin for "of uncertain placement") within the ant subfamily Myrmeciinae, as the ants could not be identified to any tribe level. However, a 2008 paper by Cesare Baroni Urbani of the University of Basel, Switzerland, expressed doubt that members of ''Ypresiomyrma'' were even ants. He notes that the development of the malar area (an area between the compound eyes and the mandibles) was different and not reduced, as a reduced malar is synapomorphic (key diagnostic traits) in Myrmeciinae. Baroni Urbani further notes that the antennae's shape on the type species could not be properly determined, making its true placement within Formicidae indeterminable. However, the antennae of ''Y. rebekkae'' has an elongated scape which means the fossil is definitely an ant, as this feature is a key diagnostic trait for Formicidae. Due to this, Baroni Urbani believed that ''Ypresiomyrma'' could only be confidently classified as ''incertae sedis'' within the family Formicidae. A subsequent report by Russian palaeoentomologist Gennady M. Dlussky describing new myrmecines accepted the classification of Archibald and colleagues without mentioning the comments of Baroni Urbani. The following cladogram generated by Archibald and colleagues show the possible phylogenetic position of ''Ypresiomyrma'' among some ants of the subfamily Myrmeciinae. The genus may be closely related to other extinct Myrmeciinae genera, including ''Avitomyrmex'' and ''Macabeemyrma'', and the extant ''Nothomyrmecia macrops''. }} }} 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「Ypresiomyrma」の詳細全文を読む スポンサード リンク
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