– Glimpse into how feathers evolved
The amber- encased specimen is the first confirmed to be from a dino. APRIL REESE reports.
About 99 million years ago, in what is now northern Burma, a tiny dinosaur about the size of a sparrow met its end, its tail ensnared in tree sap.
But what was a fatal misstep for the Cretaceous-era dinosaur turned out to be a gift to science. The amber-encased tail, extracted from its resting place in the Hukawng Valley by gem miners, has offered scientists the first 3-D view of a completely intact, feathered dinosaur tail.
“In the past, feathers have been found in amber, but their source animals have been difficult to pin down,” says palaeontologist Lida Xing of the China University of Geosciences, who was tipped off about the sample by an amber dealer. Xing and his team described the find in Current Biology in December.
The tail was flexible, with eight articulated vertebrae. This ruled out the possibility that it belonged to an ancestor of birds, whose tail vertebrae, like those of modern birds, were fused.
The well-preserved dinosaur tail, which likely belonged to a juvenile coelurosaur, reveals new details about how feathers evolved.
A CT scan of the specimen showed feathers ran down the tail, but they lacked the well-developed central shaft, or rachis, found in feathers used in flight. That supports the theory that animals first developed feathers not to fly but perhaps for camouflage, or attracting mates.