Ancient Orb Weaver Found in Amber
Posted on June 19, 2006
An ancient orb weaver spider has been discovered preserved in amber from 121-115 million years ago. A BBC article about the discovery explains how the web of orb weavers has adapted over millions of years to be able to catch moths with scales that rub off.
The evolutionary success of this design can be seen in the high diversity of true orb weavers, which currently number 2,847 living species.The BBC also provided this interesting link which explains how orb weavers create their fantastic webs. One interesting fact in the article is that the spiders rebuild almost the entire web every night or every other night. Some photographs of orb weavers that reside in North America can be found here.This astonishing diversity also owes much to the way in which the basic design can be easily modified.
"One modification to the web is quite fantastic," Dr Penney told the BBC News website.
"Picture a normal, spiral orb web and picture running down from it a ladder-type structure which is also made from sticky silk. This has evolved to trap moths, which have scales that rub off.
"When a moth flies into a normal orb web, it's the scales that stick and the moth tumbles out of it. But with the ladder structure, the moth tumbles down until all the scales come off and eventually it gets caught."