Trapped in a scientific net, oldest spider web

[Ferran]

Trapped in a scientific net, oldest spider web

23 June 2006

TERUEL - Scientists have found the oldest known example of an insect-trapping spiderweb, a silky net that caught the prey while dinosaurs still roamed, according to a study published on Friday.

The spiderweb dating from 110 million years ago is preserved within several pieces of the fossilized resin found in 2003 in a coal mine in the San Just mountains, in the Spanish region of Aragon.

The amber, which was unveiled at a press conference at the Dinopolis Foundation in Teruel by the Spanish qnd US scientists who discovered it, consists of three small fragments within which the web with tiny trapped prey is encased.

The study performed on the find, the results of which will be published on Friday in Science magazine, was carried out by Spanish scientists Enrique Peñalver and Xavier Delclos of Valencia and Barcelona universities, respectively, and an expert from New York's American Museum of Natural History, David Grimaldi.

Delclos said that the spiderweb originally must have been about 2-3 centimetres wide and that the portion of it found in the amber is just 5-6 millimetres wide.

The web was sticky, elastic, roughly circular in shape and hung vertically, supported by a system of radial strands, in other words, a "complete web," Delclos said.

Peñalver, a biologist, who emphasized the paleontological importance of the deposits in the San Just mountains, detailed the insects that are trapped in the web: a mite, a wasp of the Evaniidae family, a beetle and a Hybotidae fly of an unknown species.

The two Spanish scientists said that the find dates from a period marked by an enormous diversification of plant species that - during the Early Cretaceous period - replaced the prevailing thick and jungle-like vegetation with wide expanses of grasses and flowering plants, a development which went hand in hand with the evolutionary specialization of insects.

Delclos said that the amber discovered in Escucha formed in a forest of conifers of the Araucariaceae family - which nowadays are found only in South America and New Zealand - located in a delta, adding that the dollop of resin fossilized along with the coal deposits that are now being mined in the region.

The fossil was discovered in late 2003 and sent to the American Museum of Natural History laboratory, where its importance was confirmed.

The amber fragments are now at the Joint Paleontological Foundation in Teruel, the director of which, Luis Alcala, said that probably they will not be publicly exhibited since the small size of the samples and the need to use a microscope to make out the trapped insects within made viewing by the public practically impossible.

The remains of the oldest known spiderweb were found in Lebanon and date from about 125 million years ago, but Delclos told EFE that that sample consisted of just "some single strands without any trapped insects," in contrast to the more complete Teruel specimen.

In the pieces of amber found in Spain, the insects appear to have been "trapped and preyed upon by the spider, which must have sucked out their bodily fluids, and - later - resin must have penetrated the (already-dead) bodies, ... something that's rather spectacular," Delclos said.

[Copyright EFE with Expatica]



Source: http://www.expatica.com/source/site_...st+spider+web+