A 305-million-year-old proto-spider fills fossil gap
Primitive arachnid was nearly-but-not-quite a spider
The images revealed that the animal's mouth parts, legs and body shape are similar to those of a true spider. There were important differences, however, in how the animal produced and used silk.
This arachnid may have used its silk to line a nest or protect eggs, but it did not have the spinnerets that would have allowed it to produce a web. It co-existed with real spiders for some time, but ultimately succumbed to extinction.