A spider that walked on land about 55 million years before the dinosaurs may have been able to spin a web.

Researchers say they've found signs of silk spinning structures on the 300-million-year-old arachnid.

The penny-sized creepy crawly, called Aphantomartus pustulatus, had a hard exoskeleton like a modern beetle.

Aphantomartus pustulatus (courtesy Ohio State University)

Scientists didn't think the eight-legged critter could spin a web.

But geologists at Ohio State University have found a well-preserved fossil with tiny bumps on its hindmost legs.

The spider belonged to ancient group of arachnids known as trigonotarbid, which were among the first animals to colonize land.

"If trigonotarbids did spin silk like a spider, they had the right structures in the right places to do it," geologist Cary Easterday of Ohio State said in a release.

Easterday, a master's degree student, cautioned there isn't conclusive evidence the bumps or "microtubercle rows" were used for spinning silk.

But he said under a microscope, the rows resembled the spinning structure found on some modern spiders.

Other possibilities include cleaning structures, or specialized hairs to trigger fight-or-flight responses.

The ancient spider may have spun silk to trap prey, line burrows or for insulation.

Paleontologist Conrad Labandeira of the Smithsonian Institution in Washington said as far as he knows, this would be the first time evidence of silk-spinning has been found in a spider fossil.

The results were presented at this week's meeting of the Geological Society of America in Seattle.