The fossil of a spider with a leg span of five inches from the Jurassic period was recently discovered in China. It’s the largest fossil specimen discovered, says Science Daily. The spider belongs to a living genus, Nephila, or golden orb-weavers, who live in tropical climates including Australia and which are pretty much the same size as their ancestors.
The nephilids are, says Science Daily, an example of a living fossil:
Nephilids are the largest web-weaving spiders alive today (body length up to 5 cm, leg span 15 cm) and are common to the tropical and subtropical regions today. This suggests that the paleoclimate of Daohugou, China, where the specimen was found, was probably similarly warm and humid during the Jurassic.
Nephila females weave some of the largest orb webs known (up to 1.5 m in diameter) with distinctive gold-colored silk to catch a wide variety of medium-sized to large insects, but occasionally bats and birds as by-catch. Typically, an orb-weaver spider first weaves a non-sticky spiral with space for sticky spirals in between. Unlike most other orb-weaving spiders, Nephila do not remove the non-sticky spirals after weaving the sticky spirals. This results in a ‘manuscript paper’ effect when the orb is seen in the sunlight, because the sticky spirals reflect the light while the non-sticky spirals do not, thus resembling musical staves.
Researchers from Kansas University and Capital Normal University (Beijing) found the fossil, which provides evidence that golden orb-webs were being woven and used to capture medium to large insects back in Jurassic times.
Go to Science Daily to see side-by-side photos of the fossil (Nephila jurassica) and a living female golden orb-weaver spider (Nephila pilipes), in Queensland, Australia. The living spider is almost the same size as the fossil.
The video below shows a golden-orb weaver spinning her web and eating a fly.
Photo by Clicksy
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