A Kansas University researcher has discovered a missing link between spiders and their ancestors.

His findings may shed new light on how spiders came by the current trump card they play in their fight against the world’s insect population: the silk used to spin webs.

Among the scientific community, there’s some debate on how that silk came to be, said Paul Selden, the director of KU’s Paleontological Institute at the Biodiversity Institute and professor of invertebrate paleontology.

Selden helped find a new kind of “pre-spider” that wove broad sheets of silk from plates attached to the undersides of their bellies.

The silk could have been used as a trail, to let the creature know it could get back to where it wanted to go, or for a variety of other purposes, Selden said.

Modern spiders make silk threads using modified appendages called spinnerets.

The small, 7-millimeter long animals Selden discovered also had a tail, unlike modern spiders.

Spiders have been around for quite some time, managing to last through whatever event killed off the dinosaurs.

With insects today being the most abundant and diverse populations on the planet, and with spiders being their main predators, it’s not too much of a stretch to call spiders the most abundant and diverse predators on the planet, Selden said.

“The silk is obviously what made spiders so successful,” he said.

When this creature was crawling around the earth 380 million years ago, there would be no need to spin webs, as there weren’t any flying insects around at the time, Selden said.

In fact, there wasn’t much of anything moving around.

“These were — and still are — the oldest known animals in North America,” Selden said.

Selden and fellow researcher William Shear, a biology professor at Hampden-Sydney College in Virginia, made the discovery by painstakingly putting together bits of fossils to help make the discovery.

“It’s like if someone gives you an old jigsaw puzzle and you’ve only got half the pieces and you don’t know what the picture on the top of the box looks like,” Selden said.