Michael Marshall, environment reporter
(Image: Paul A. Selden, ChungKun Shih and Dong Ren/Biology Letters)
Meet Nephila jurassica, a 165-million-year-old spider fossil recently found in China. A relative of the modern golden orb-weaving spider, it's the largest fossil spider ever found.
And yet it is disappointingly small. The scale bar on the image is 5 millimetres, so the whole specimen is barely 5 centimetres long - though it may have been larger in life, with its legs fully extended. By comparison the biggest living spiders are the Goliath bird-eater (Theraphosa blondi) and the giant huntsman (Heteropoda maxima), both of which have leg spans of 30 cm.
On the face of it that's surprising, because related creatures like insects were much larger in the past. Around 300 million years ago, oxygen levels were much higher than today. Invertebrates - many of which rely on simple diffusion rather than a circulatory system to delivery oxygen to their tissues - grew to monstrous sizes. Some dragonflies had wingspans of up to a metre, while some millipedes were 2.5 metres long.
All of which suggests that there are some much bigger fossil spiders out there, waiting to be discovered.