Palaeontologists in Inner Mongolia have announced the discovery of a nearly complete fossil of a giant Jurassic-era arachnid that features primitive, hair-like structures resembling feathers. The specimen, named Araneae plumosus, measures nearly 12 inches across and was found in a layer of fine volcanic ash that preserved delicate soft tissues. This finding challenges previous assumptions about the evolution of sensory structures in ancient spiders, suggesting these "feathers" may have served as advanced vibration sensors.
The volcanic preservation also captured the spider's complex mouthparts and spinning organs in 3D detail. Analysis indicates that this species lived in a humid, forested environment where it likely used its feathered limbs to detect the subtle movements of flying insects. The discovery adds a surprising new branch to the evolutionary tree of arachnids, highlighting how prehistoric species adapted to the dense ecosystems of the late Jurassic period.