Named By: Ji Shu'an & Ji Qiang - 1997.
Classification: Chordata, Reptilia, Pterosauria, Pterodactyloidea.
Species: E. yangi (type).
Size: Estimated 1.2 meter wingspan.
Known locations: China, Liaoning Province - Yixian Formation.
Time period: Barremian to Aptian of the Cretaceous.
Fossil representation: Partial skeleton.
has enjoyed a variable position amongst the pterosaurs first being
thought to be similar to Pterodactylus,
then thought to have been a
member of the filter feeding ctenochasmid pterosaurs, perhaps like
to ultimately being declared to be similar to
The overall physiology of Eosipterus is quite
especially the wings. The interesting thing about Eosipterus
is how the
legs are proportionately smaller to other pterosaurs with a reduced
fibula. The fifth toe is also only represented by a claw, with the
claws on the other four toes being curved.
These adaptations may suggest that Eosipterus did not spend a lot of time on the ground, and may have been more at home amongst the trees. The curved claws could be used for gripping into bark, the legs not being used for ground locomotion became underdeveloped, and the wings being more robust would be better able to withstand brushes and scrapes with branches as Eosipterus flew amongst the trees.