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''Juramaia'' is an extinct genus of very basal eutherian mammal from the Late Jurassic (Oxfordian stage) deposits of western Liaoning, China; it is a small shrew-like mammal of body length approximately 70-100 mm.〔(Juramaia sinensis - 160-Million-Year-Old Fossil Pushes Back Mammal Evolution )〕 ''Juramaia'' is known from the holotype BMNH PM1343, an articulated and nearly complete skeleton including incomplete skull preserved with full dentition. It was collected in the Daxigou site, Jianchang, from the Tiaojishan Formation dated at about . It was first named by Zhe-Xi Luo, Chong-Xi Yuan, Qing-Jin Meng and Qiang Ji in 2011 and the type species is ''Juramaia sinensis''.〔 (Electronic supplementary material )〕 The discovery of ''Juramaia'' provides new insight into the evolution of placental mammals by showing that their lineage diverged from that of the marsupials 35 million years earlier than previously thought.〔 Furthermore, its discovery fills gaps in the fossil record and helps to calibrate modern, DNA-based methods of dating the evolution.〔("Fossil redefines mammal history" BBC News )〕〔(Discovery of a 160-million-year-old fossil represents a new milestone in early mammal evolution )〕 Based on climbing adaptations found in the forelimb bones, it has been suggested that the basal stock of Eutheria was arboral.〔 }} }} == See also == * Eomaia 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「Juramaia」の詳細全文を読む スポンサード リンク
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