Mollisonia plenovenatrix preserved in dorsal view, showing the large eyes, the walking legs and the small chelicerae at the front. Alberta’s famed Burgess Shales have yielded another ground-breaking fossil find — this time the oldest known ancestor of today’s spiders and scorpions. (Jean-Bernard Caron-Royal Ontario Museum)

‘Staring at me:’ Oldest known spider ancestor found in B.C.’s Burgess Shale

‘I turned my head to the right and I see this glowing light coming from this rock’

Tiny eyes blinking at him from the rockface of the Burgess Shale near Field, B.C., drew Jean-Bernard Caron to the fossil of the oldest known ancestor of today’s spiders and scorpions.

“I was sitting there along the quarry and I turned my head to the right and I see this glowing light coming from this rock,” he said. “Two eyes, almost staring at me.”

The eyes turned out to belong to a 500-million-year-old specimen of Mollisonia plenovenatrix — so well preserved that Caron and his colleague Cedric Aria were able for the first time to definitively place the long-gone beastie at the root of a family tree that now boasts thousands of branches.

It was only thumb-sized, a scurrier of ancient sea bottoms. Still, the two paleontologists from the Royal Ontario Museum say it would have a been a fierce predator.

ALSO READ: Epic animal fossil discovery in Kootenay National Park

Large eyes spotted prey. Long limbs propelled it across the sediments. Its head was like a modern multi-tool with limbs that could sense, grasp, crush and chew.

The tiny pair of structures in front of its mouth really got Caron and Aria excited.

Those same pincers can be seen on all members of the family Chelicerata. That’s 115,000 different species, and here was their progenitor.

“I was really excited about this,” said Caron, who published his findings Wednesday in the journal Nature.

“Those fossils tell us about the origin of key innovations in animal evolution. It’s important to understand how they happen. Because when they happen, there is often an explosion of life that is the consequence.”

Intriguingly, the species was clearly some distance along its evolutionary path, well-adapted to its environment and breathing through thin gills layered like the pages of a book.

“This discovery tells us that at the time of the Cambrian they were already there,” Caron said. “They probably evolved earlier than that.”

That means there’s probably another, even older ancestor out there — maybe waiting in the same Burgess Shale of southeastern British Columbia.

Those rocks are renowned the world over for their wealth of fossils from the middle Cambrian period, a time when the Earth’s biodiversity exploded. What sets Burgess specimens apart is the clarity with which the soft parts of the animals are preserved.

“I feel like a boy in a candy store,” Caron said. “There are a lot of candies to choose from and the question is which one I’m going to pick and describe first.

“We could work for decades there and still feel we haven’t scratched the surface. There’s still a lot ground we haven’t covered.”

Look for the eyes, said Caron.

“The eyes are very reflective. It’s very striking. Many fossils that we discover in the rocks, the first thing you see are the eyes, like shiny spots in the rock.”

Bob Weber, The Canadian Press

Like us on Facebook and follow us on Twitter.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Sternwheelers once plied Okanagan Lake

Vessels once transported passengers and goods along the Okanagan Valley

Fires ignite on Revelstoke’s Mt. Begbie; Kamloops Fire Centre blazes holding

Crews working throughout region over holiday weekend to contain wildfires

QUIZ: How much do you know about British Columbia?

On this B.C. Day long weekend, put your knowledge of our province to the test

QUIZ: How much do you know about British Columbia?

On this B.C. Day long weekend, put your knowledge of our province to the test

Fourteen blazes sparked in Kamloops Fire Centre

Lightning the suspected cause of all fires but one; cause of Solco Creek blaze remains unknown

VIDEO: Otter pups learn to swim at B.C. wildlife rescue facility

Watch Critter Care’s Nathan Wagstaffe help seven young otters go for their first dip

Plane crashes into Nelson supermarket parking lot

Pilot and passenger have minor injuries

Thompson Okanagan Tourist Association: Who can’t access your business?

TOTA launches video to encourage proprietors to remove barriers

Shuswap pet nutritionist, raw diet advocate to be featured in national magazine

Sicamous-based Deanna Larocque building reputation for canine support

BC RCMP notify IIO BC of incident involving police dog in Kelowna

A suspect and a police dog were taken to receive medical treatment after an incident on Aug. 1.

Alberta man presumed to have drowned after cliff jumping in Peachland

Emergency responders began rescue efforts at around 2:40 p.m. on Aug. 1.

Michael Buble among 13 British Columbians to receive Order of B.C.

Ceremony will be delayed to 2021 due to COVID-19

U.S. border communities feel loss of Canadian tourists, shoppers and friends

Restrictions on non-essential travel across the Canada-U.S. border have been in place since March 2`

Rollout of COVID-19 Alert app faces criticism over accessibility

App requires users to have Apple or Android phones made in the last five years, and a relatively new operating system

Most Read