Roughly 410 million years ago, a creepy little creature called Eophrynus prestvicii stalked the land. In fact, this ancient arachnid was one of the first land predators on Earth, preying on the completely unprepared insect population. This species is known from several well-preserved fossil specimens, and now a team from the University of Manchester led by Russell Garwood has brought it back to life as a computer simulation. You can now watch Eophrynus prestvicii take its first steps in hundreds of millions of years.
It wouldn’t be accurate to call E. prestvicii a spider — it’s actually a trigonotarbid, a spider-like arachnid from the time before spiders existed. It certainly had the basic body shape and features we associate with spiders, but silk-producing spinnerets had yet to evolve (it looks a bit like a tick). This was the first species of trigonotarbid to be described way back in 1837, and multiple fossils have been found since then. Even knowing as much as we do about E. prestvicii, we didn’t know how it moved, until now.
The researchers used X-ray micro-tomography (XMT) to reconstruct the exact dimensions of the original creature from fossils. Minute details like the internal muscle structure were revealed, allowing for a more accurate picture of the arachnid than we previously had. This allowed Garwood to calculate the range of movement in the limbs. By comparing E. prestvicii to modern arachnids, the creature’s gait was reconstructed in a computer simulation. The animation above was actually made in the free open source Blender design program.
Eophrynus prestvicii will never walk the Earth again in real life, but at least it gets to take one more stroll virtually. Fossils of trigonotarbid have occasionally been split into different species because of minor perceived differences, only to be reunited years later. Techniques like XMT and 3D animation might prevent paleontological missteps like that in the future.