Largest Fossil Spider Ever Found Gives Peek Into Arachnid Evolution | 80beats | Discover Magazine

 

Largest Fossil Spider Ever Found Gives Peek Into Arachnid Evolution

. .

0diggsdigg

Nephila jurassica, with a 5mm scale bar

What’s the News: Researchers have unearthed the largest fossilized spider yet, announced in a study online today in Biology Letters. The fossil, a Jurassic Period ancestor of the modern orb-weaver spider,  gives scientists a glimpse not only into the evolutionary history of orb-weaver spiders, but how these ancient arachnids might have impacted the evolution of insect species that could be snared in the webs.

How the Heck:

• The fossil, found preserved in volcanic ash in the  Daohugou fossil beds in northeastern China, dates back 165 million years. The researchers dubbed the species Nephila jurassica.
• At about an inch long, the spider’s body isn’t unusually large, but its leg span, at nearly six inches, is the largest seen in a fossil spider.
• This spider was female, suggesting the size disparity seen in modern orb-weaver spiders—with females dwarfing the males—may have begun at least 165 million years ago.
• Silk spinning organs, called spinnerets, preserved on the fossilized spider’s legs suggest that, like its modern counterparts, Nephila jurassica spun big, durable webs.
• The spider’s formidable prey-catching ability likely drove the evolution of the medium-to-large insects it fed on, as those species scrambled to survive, the researchers wrote.

What’s the Context:

• Until now, the earliest known fossil from the Nephila genus was 34 million years old; this find pushes back the origin of the genus 130 million years from what researchers previously thought.
• Modern orb-weaver spiders live in tropical climes, so this fossil suggests that the region where it was found may have had a much muggier climate during the Jurassic than it does today.
• The oldest fossil spiders ever found are nearly twice as old as this specimen, dating back 310 million years.
• While its size is remarkable for a fossilized spider, Nephila jurassica‘s legspan is only half as big as that of the world’s largest living spiders, the evocatively named goliath bird-eater and giant huntsman.

Reference: Paul A. Selden, ChungKun Shih and Dong Ren. “A golden orb-weaver spider (Araneae: Nephilidae: Nephila) from the Middle Jurassic of China.” Biology Letters online before print, April 20, 2011. DOI: 10.1098/rsbl.2011.0228

Image: Selden et al. paper

Largest Fossil Spider Ever Found Gives Peek Into Arachnid Evolution | 80beats | Discover Magazine

The Paleontology Portal: Home

The Paleontology Portal: Home

This site is a resource for anyone interested in paleontology, from the professional in the lab to the interested amateur scouting for fossils to the student in any classroom. We have gathered many different resources into this single entry "portal" to paleontological information on the Internet. Take our site tour to find out more about what you will find here.

Images and links that you see as you browse through the site have been reviewed and selected for quality by one or more members of the Editorial Board, following the guidelines of the established editorial policy. Please use the "add to site" link at the top of the page to contribute images or links for consideration.

This site was produced by the University of California Museum of Paleontology, the Paleontological Society, the Society of Vertebrate Paleontology, and the United States Geological Survey. The site was funded by the National Science Foundation under award no. 0234594. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

 

The Paleontology Portal: Home

Encyclopedia of Earth

Encyclopedia of Earth

Welcome to the Encyclopedia of Earth, a new electronic reference about the Earth, its natural environments, and their interaction with society. The Encyclopedia is a free, fully searchable collection of articles written by scholars, professionals, educators, and experts who collaborate and review each other's work. The articles are written in non-technical language and will be useful to students, educators, scholars, professionals, as well as to the general public.

Encyclopedia of Earth

GeoGuide Startseite

GeoGuide Startseite 

The Geo-Guide is a subject gateway to scholarly relevant websites in earth sciences, geography and mining maintained in cooperation by the:

• Goettingen State and University Library
• University Library "Georgius Agricola" Freiberg

It is part of the Virtual Library Earth Sciences, Geography and Mining GEO-LEO.

GeoGuide Startseite