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

UPDATE: Man missing in Clayton Heights found safe

Family and police were concerned for his wellbeing

South Surrey’s Rialto Theatre shutters after 200 % rent increase imposed

Owner says he’s devastated by the closure of the 26-year-old business

TransLink CEO asks riders not to enforce mask rules after Surrey bus punch-up

A fight broke out on a bus at 96 Avenue and Scott Road involving a man who refused to wear a mask

Weekend sees 267 cases, 3 deaths in B.C.; Dr. Henry says events leading to COVID spread

There are currently 1,302 active cases in B.C., while 3,372 people are under public health monitoring

Search suspended for Indigenous elder last seen mushroom picking in northwest B.C.

Mushroom picker Thomas (Tommy) Dennis has been missing since Sept. 16

Ahead of likely second wave, 60% of Canadians relaxing COVID-19 measures

Proportion of Canadians not following safety measures has dropped by 3 per cent in the past two weeks

Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Canada’s population tops 38 million, even as COVID-19 pandemic slows growth

Immigration, the top population driver, decreased due to the pandemic

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Lightning strike: Tampa Bay blanks Dallas 2-0 to win Stanley Cup

Hedman wins Conn Smythe Trophy as playoff MVP

16 MLAs retiring from B.C. politics add up to $20M in pensions: Taxpayers Federation

Taxpayers pay $4 for every dollar MLAs contribute to their pensions

Liberals seek to fast track new COVID-19 aid bill after CERB expires

Government secured NDP support for legislation by hiking amount of benefits by $100 to $500 per week

Most Read