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

Nak’azdli and UNBC form partnership to preserve inter-generational stories

“Stories can empower. Stories can bring people together. Stories can be instructive,”… Continue reading

B.C. premier talks forestry, service needs with handful of northern mayors in Prince George

Prince George meeting completes premier’s tour of Kitimat, Terrace, Fort St. James and Quesnel

Indigenous LNG supporters chide human rights advocates over pipeline comments

Coastal GasLink has signed agreements with 20 elected First Nation councils along the pipeline’s 670-kilometre path

Cluculz Lake fire leads to death of occupant

RCMP said mobile home was engulfed in fire when they arrived on scene

VIDEO: Rare ‘ice circle’ spotted on Kamloops river

An ice circle or ice pan, has formed in the chilly waters just east of the Yellowhead Bridge

Uber, Lyft approved for ride-hailing in Lower Mainland

Kater Technologies Inc.’s application was rejected

B.C. man rescued after getting trapped headfirst in well as water level rose

The rescue involved crews from Oak Bay and Saanich

Investigators in wildfire-torn Australia head to site of B.C. airtanker crash

The B.C. government sends condolences to Port Alberni-owned Coulson Aviation

RCMP investigating sexual allegation against Lower Mainland police officer

Delta officer suspended while the alleged off-duty incident involving a co-worker is investigated

Former Mountie, sports coach convicted of sex abuse in B.C. granted day parole

Alan Davidson was sentenced to almost six years for abusing seven boys in the late 1970s and early 1990s

VIDEO: Person in wheelchair narrowly avoids collision with car in Kelowna

There were no injuries in the scary looking near-accident last week in Rutland

Here’s what Canada is doing to stop the coronavirus from getting in

Health officials are monitoring multiple possible cases in Canada

B.C. still struggling to control non-resident medical care fraud

Unpaid bills, out-of-province claimants a costly legacy of MSP

Most Read