London: Researchers have unearthed the world’s largest known spider fossil - 165 million years old with a six inch leg span - from the Inner Mongolian region of China.
Its fossilized features have been so perfectly preserved that experts have identified it down to the exact species and were even able to tell it was an adult female, reports the Daily Mail.
The Golden Orb Weaver, named Nephila jurassica, is roughly the size of the spider’s modern-day descendants, with a body one-inch long and more than half an inch wide, and legs that stretch to 2.5in.
It lived in the forests of northern China when the climate was much warmer and more tropical than today.
Its discovery means Golden Orb Weavers, or ''nephilids'' - giant spiders that can grow bigger than a human hand and which still thrive today - are the longest ranging spider genus known to man in terms of age.
Palaeontologist professor Paul Selden, of Kansas University, said the females are the largest web-weaving spiders alive today with a body length of up to 2in and a leg span of 6in. Males are relatively small in comparison.
They are ''common and spectacular'' inhabitants of tropical and subtropical regions with females weaving distinctive 5ft-wide webs of yellow silk that glisten like gold in sunlight.
The pristine Nephila jurassica was probably created when the spider was quickly encased in a tomb of silt and ash during a volcanic eruption to keep it from being scavenged or decaying.
Prof Selden said the find means Golden Orb Weavers must have an unusually ancient lineage, an extremely long range for any animal genus.
The discovery is reported in the Royal Society journal Biology Letters.
First Published: Wednesday, April 27, 2011, 09:29