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.

Just Posted

LETTER: Democracy concerns must be addressed

Critical issues keep some from voting

21 years: Grand Chief Stewart Philip to continue leading B.C. Indian Chiefs union

Grand Chief Stewart Phillip acclaimed as president of Union of BC Indian Chiefs

Summerland cadet earns glider wings

Summer training program was held at CFB Comox on Vancouver Island

Students down and very dirty at Freak’N Farmer

Students had a chance during the past two weeks to try out the Freak’N Farmer obstacle course

Concert raised funds for Agur Lake Camp

Tim Nutt was headline act at Comedy Night Fundraiser in Summerland

VIDEO: Trudeau asks Canada to look to current, not past, actions on race

Liberal leader says he never spoke about the racist photo because he was embarrassed

Photos surface of Conservative candidate at B.C. event with people in blackface

The controversial “Black Peter” character has been a feature at Sinterklaas celebrations

B.C. Liberal leader says private sector development will help housing affordability

Andrew Wilkenson spoke in Kelowna during a real estate conference

Legislature gifts, clothing, travel need better control, B.C. auditor says

Audit follows suspensions of managers by Speaker Darryl Plecas

‘Really disturbing:’ Trudeau’s racist photos worry B.C. First Nation chief

Wet’suwet’en Chief concerned the photos will sow fear in Indigenous communities

Human case of West Nile virus reported in Okanagan

B.C. Centre for Disease Control confirmed case reported in August

Murder charges laid after body pulled from Fraser River ID’ed as missing man

Accused also face one count each of attempted murder in connection with Rudy Johnson Bridge incident

B.C. salmon farm inspection deal reached with Indigenous people

Monitoring to determine if any Broughton region farms stay open

‘I felt betrayed’: North-Okanagan Shuswap candidate responds to Trudeau brownface photo

Harwinder Sandhu dismisses comments that there are bigger issues to focus on

Most Read