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

Hybrid vessels part of B.C. Ferries’ plans to reduce emissions

Long-term goal of B.C. Ferries is to have a “standardized” all-electric fleet

Former runaway teen helps find missing youths through social media

Alex Meikle created the Facebook group Greater Victoria Missing & Runaway Teens

Vancouver Island students empowered to ‘shift the vote’ this election

VIU Students’ Union, B.C. Federation of Students launch ‘Our Time is Now’ campaign

OPINION: The smoke and mirrors of indigenous acknowledgments

We want action, we get nothing more than box-ticking

Saanich mayor begins living roof planting process

A garden will top Mayor Fred Haynes’ new home on Prospect Lake

VIDEO: ‘Thrones,’ ‘Fleabag’ top Emmys

Billy Porter makes history as first openly gay black man to win best drama-series acting Emmy

‘This is savage’: Strip club owner suspects arson in Williams Lake fire

Investigators on scene to determine cause of fire that destroyed at least two businesses

B.C. VIEWS: School officials join fact-free ‘climate strike’

Students, public get distorted picture of greenhouse gases

Judge rules cops did not coerce statement from B.C. man accused of assaulting sex worker

Defence wanted Vernon’s Curtis Sagmoen’s video interview with police deemed inadmissible

GRAPHIC: Tortured cat found with string around its neck in Kelowna alleyway

City crews have been contacted and are on the way to pick up the dead feline.

Firefighters may be needed for paramedic apartment access, experts say

Better coordination recommended in urban B.C. 9-1-1 calls

One-man Frankenstein show coming to Craigdarroch Castle

The Halloween special will kick off at the beginning of October

Let Downchild chase those blues away

Donnie Walsh and company celebrate the band’s 50th year with Vancouver Island tour

New standards, new maintenance company for south Vancouver Island roads

Province demanding higher standards as Emcon takes over road contract from Mainroad

Most Read