It was collected in the Daxigou site,
Jianchang, from the
Tiaojishan Formation dated at about 160 million years ago.[4] 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.[5]
Evolution
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.[5] Furthermore, its discovery fills gaps in the fossil record and helps to calibrate modern, DNA-based methods of dating the evolution.[6][7] Based on climbing adaptations found in the forelimb bones, it has been suggested that the basal stock of Eutheria was arboreal,[5] in a manner resembling that of modern rats.[8]