Spooky spider-like critters were already roaming the Earth long before dinosaurs. And now, with the help of a new imaging technique, the arachnids can be seen as they appeared to their early insect prey about 300 million years ago.

"Our models almost bring these ancient creatures back to life and it's really exciting to be able to look at them in such detail," said Russell Garwood, lead author of a paper on the new images, in a prepared statement.

Using a CT-scanning device, Garwood and his colleagues at Imperial College London took 3,000 X-rays of fossilized Cryptomartus hindi and Eophrynus prestvicii specimens. Then the paleontologists pieced the pictures together into 3-D models, which detail everything from tiny claws to prickly spines.

The researchers found that both species were about 2.5 centimeters long, but each had different means of using their anatomy for survival. C. hindi’s front two legs angled forward, suggesting it might have ambushed and grabbed its prey. E. prestvicii, on the other hand, was endowed with longer legs, allowing it to scurry faster along the forest floor after its meals.

"Our study helps build a picture of what was happening during this period early in the history of life on land," Garwood said. There may not yet have been any arachnophobes, but it appears there was already plenty of fodder for a horror film.

The research was published yesterday in Biology Letters.

Video of E. prestvicii model courtesy of the Natural History Museum and Imperial College London