Named By: Zhe-Xi Luo, Chong-Xi Yuan, Qing-Jin Meng & Qiang Ji - 2011.
Classification: Chordata, Mammalia, Eutheria.
Species: J. sinensis (type).
Size: Precise body size unavailable, but the skull is measured at 22 millimetres long.
Known locations: China, Liaoning Province - Tiaojishan Formation.
Time period: Callovian to Bathonian of the Jurassic.
Fossil representation: Almost complete skeleton preserved on slab.
significant thing about the discovery of Juramaia
is that here you have
a placental mammal appearing thirty-five million years earlier than
the previously known contender Eomaia,
a primitive mammal
described in 2002 that was also discovered in Liaoning Province.
This has helped researchers who are slowly piecing together a more
complete picture of early mammal evolution, particularly that
pertaining to placental mammals, a group that today encompasses many
groups from whales to cats, dogs, horses and even primates and
Juramaia is thought to have been an arboreal creature living that lived in around the tree canopy and/or dense vegetation where it could hide from Jurassic era dinosaurs such as Xiaotingia and Anchiornis. Another evolutionary important find from the Tiaojishan Formation is the pterosaur Darwinopterus that displays the transition between primitive and advanced pterosaurs.
- A Jurassic eutherian mammal and divergence of marsupials and placentals. - Nature. 476 (7361): 442–445. - Zhe-Xi Luo, Chong-Xi Yuan, Qing-Jin Meng & Qiang Ji - 2011.