In the natural world, few creatures exhibit ingenuity quite like the spider. Small and unassuming, they are master architects. Their webs, constructed from silk, are delicate and beautiful to us, but are deadly to the spider’s prey. This silk, lighter than air yet stronger than steel by weight, is one of evolution’s most extraordinary designs. But silk alone is not a weapon! Welcome to Wildlife In Focus. In this article, we will examine the evolution of spider webs and how they developed their simple silk threads into some of the most sophisticated traps on Earth!
Silk rarely preserves and fossilises. Yet here, in the UK, lies the oldest known web; 140 million years old. This means that even in the time of the dinosaurs, spiders were already casting snares much like those we see today.
But the story begins much earlier. Over 400 million years ago, spider-like ancestors first crept from the seas. The world they entered was alien, with days lasting only 21 hours. The tallest organisms on the planet at this time were giant fungi, standing up to eight meters high.
Fast forward now to the Carboniferous period, and forests blanketed the Earth. Among their shadows appeared the first true spider; small, resembling their modern descendants but with segmented abdomens, a mark of their ancient heritage.
Yet silk itself predates true spiders. This creature, Attercopus, lived 380 million years ago. It had silk glands but no spinnerets; its threads were crude, perhaps used to line its burrow or protect its eggs.
If we return to the Cretaceous period, Chimerarachne is found encased in Burmese amber. Chimerarachne had a tail and true spinnerets. Its silk may have been used across the forest floor as a primitive trap.
A major turning point occurred when insects learned to fly. The first fliers, emerging 350 million years ago, had few predators above them. However, the emergence of the spider, with silk at its command, found a new opportunity.
These Bolas Spiders use a simple strand of silk to bring down prey from the air.
As insects evolved to become faster and more elusive, spiders adapted in response. An arms race had begun. Some insects learned to escape by shedding scales as they moved through the sticky silk. However, spiders developed a countermeasure by stretching their webs, causing tumbling insects to get trapped in multiple sticky strands.
What began as a simple thread of silk evolved into one of nature’s most remarkable designs; both delicate and deadly. The spider’s web serves as a reminder that even the smallest of creatures can shape the destiny of life on Earth.
Citations
- Brasier, M., Cotton, L. and Yenney, I. (2009) ‘First report of amber with spider webs and microbial inclusions from the earliest Cretaceous (c. 140 Ma) of Hastings, Sussex’, Journal of the Geological Society, 166(6), pp. 989–997. [Accessed 25/08/2025]. ↩︎
- Selden, P. A., W. A. Shear & M. D. Sutton. 2008. Fossil evidence for the origin of spider spinnerets, and a proposed arachnid order. Proceedings of the National Academy of Sciences of the USA 105 (52): 20781-20785. [Accessed 25/08/2025] ↩︎
- By Qohelet12 – Own work, CC BY-SA 4.0, [Accessed 25/08/2025] ↩︎
- By Gonzalo Giribet – [Accessed 25/08/2025], [Accessed 25/08/2025] ↩︎
- By Judy Gallagher – Bolas Spider – Mastophora phrynosoma, Julie Metz Wetlands, Woodbridge, Virginia, November 2, 2017, CC BY 2.0, [Accessed 25/08/2025] ↩︎
