Epidendrosaurus ningchengensis
"upon branch lizard from Ningcheng County"

     It's always exciting when an entirely new family of dinosaurs is discovered. In early 2000, it was announced that a strange, apparently arboreal maniraptoran had been discovered, with an extremely long third finger, similar to that of the aye-aye lemur. It wasn't until August 2002 however that this animal was finally described, shortly after (or just before, depending on the validity of publication dates) a very similar animal, likely a member of the same family - Epidendrosaurus. The original aye-aye theropod was named Scansoriopteryx for its apparently tree-dwelling lifestyle, but these two specimens probably represent the same species (see the Wikipedia article I wrote on this animal). A juvenile with many bizarre skeletal features (some similar to lizards!), Epidendrosaurus was no bigger than a sparrow, though it likely grew larger as an adult. Since it came from the famous Liaoning deposits of China, it's not surprising that one specimen preserved feathers, though the exact relationship of the aye-aye dinosaurs to other theropods is unknown. Among the unusual features of Epidendrosaurus - the elongated third finger, possibly used to dig insects out of holes in branches, the eye with a fused sclerotic ring, small feet adapted for perching/climbing, and a short, stiffened stabilizing tail, probably adorned with a feather fan like other maniraptorans.

     Update: 4/19/05
     Two years after this page went up, I sketched the above version of Epidendrosaurus. It is more birdlike than the primate-like 2002 version. Interestingly, aye-aye dinosaurs are now considered by some researchers to be an early type of true bird within the clade Aves. The old version, while not as birdlike, is still a plausible restoration since a) aye-ayes appear to be highly specialized even for birds and b) it is meant to represent the known, juvenile specimens, sans well-developed wings and contour feathers.

Older version - image and above description published in the newsletter of the Ottawa Paleontological Society, December 2002.

A speculative drawing of an adult Epidendrosaurus.