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130 mya Spider Thread Found In Amber



I find the little stuff more fascinating than the big stuff sometimes!
It's things like this that help fill in the picture.

(subscription required)
http://www.sciencenews.org/20030830/note11.asp

A look inside a piece of 130-million-year-old amber found in Lebanon has
revealed a gossamer treasure: a filament of spider silk laced with sticky
droplets that look just like those from modern spiders.

The 4-millimeter-long strand of viscid silkthe glue-covered type that some
web-spinning spiders use to capture preyis more than 90 million years
older than any known sample of spider silk.

Despite its age, the strand has hallmarks of modern spider silk, says
Samuel Zschokke, a biologist at the University of Basel in Switzerland.
For example, most of the filament's glue droplets range from 7 to 29
micrometers in diameter and are arranged in an alternating sequence of
small and large. Zschokke describes the delicate fossil in the Aug. 7
Nature.

Both modern orb-weaver spiders and comb-footed spiders spin this type of
silk. If the fossil filament came from an ancestor of one of those
varieties, it was probably a comb-footed spider, says Zschokke. Today,
those arachnids are the only ones that spin webs bearing viscid silk near
tree trunks, where seeping resin would be likely to trap a stray strand of
silk. 


Abstract at


http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v424/n6949/abs/424636a_fs.html&dynoptions=doi1063483202

Palaeontology: Spider-web silk from the Early Cretaceous

The use of viscid silk in aerial webs as a means to capture prey was a key
innovation of araneoid spiders and has contributed largely to their
ecological success. Here I describe a single silk thread from a spider's
web that bears glue droplets and has been preserved in Lebanese amber from
the Early Cretaceous period for about 130 million years. This specimen not
only demonstrates the antiquity of viscid silk and of the spider
superfamily Araneoidea, but is also some 90 million years older than the
oldest viscid spider thread previously reported in Baltic amber from the
Eocene epoch.