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

Players needed to keep Mill Bay hockey league alive

MBRHL is province’s longest running rec league

North Cowichan to consider new report on Quamichan Lake

Report would look at ways to reduce phosphorous into lake

Cowichan players off to lacrosse worlds

Local athletes suiting up for Australia, England and Finland

UPDATE: Elderly woman missing from Maple Bay has been found

Mounties have put in a call for the police dog services

LMG collects draw and loss all in one game

Cowichan earns draw in league standings, loses shootout for cup

Chilliwack woman wins right to medically assisted death after three-year court battle

Julia Lamb has been the lead plaintiff in a legal battle to ease restrictions on Canada’s assisted dying laws

NDP, Liberals promise more spending, while Tories promise spending cuts

Making life more affordable for Canadians a focus in the 2019 election

UPDATE: Police probe third threat against a Kamloops high school in eight days

Police have not released any further details into what the threat includes

Charges dropped against Mountie involved in shooting death of Surrey man

‘I feel like I’ve lost Hudson all over again,’ says mom

B.C. Interior caribou protection area big enough, minister says

Proposals sparked protest in Kootenays, Williams Lake region

Two B.C. women selected to compete on ABC’s The Bachelor

Mykenna Dorn and Alexis Thind will compete for bachelor Peter Weber’s heart

Vaping-related illness confirmed in Ontario believed to be first in Canada

Middlesex-London Health Unit had no further details about the case — believed to be the first confirmed in Canada

Canadian stars Virtue, Moir say in video they’re ‘stepping away’ from ice dancing

The pair thank fans for their support in an emotional message

Woman held at gunpoint during carjacking in UBC parkade

University RCMP say the vehicle is still missing, and two suspects are at large

Most Read