This Eophrynus prestivicii might look like a spider you'd see setting up shop in your basement, but it's actually a fossil that pre-dates the dinosaurs, having roamed the Earth about 300 million years ago.

Scientists found the proto-spider frozen in the mineral siderite (no, not carbonite) in England and used an X-ray version of a CT scan to image it. The X-rays picked up details as fine as 20 micrometers, revealing much about the animal's natural history.

For instance, researchers say Eophrynus was probably an ambush predator that pounced on passing insects and grabbed them with those nasty-looking, forward-angled front legs.