500-million-year-old specimen

[LovelyLadyLux]

Just a very interesting science tidbit -

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)

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‘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.

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

[Horus]

I have often watched programmes that have featured the Burgess Shales, quite a remote area to reach if I remember correctly. It is facinating what they keep finding in these shale layers, the one in China is very fine grained and can be opened like the pages in a book, lots of early bird ancestors have been discovered there.

[LovelyLadyLux]

Years ago the oldest daughter got a job with a local Musuem on the Island for the summer. The claim to fame of this small Museum is the "Elasmosaur" dinosaur that two amateur dino hunters/paleontologists found along the banks of the Puntledge River.

All the rocks all along that river are easily broken with rock hammers and the number of fossil finds amazing. The daughter took me of an afternoon and I could see that fossil hunting could become extreme addicting. I loved it although I only got to do it for that one afternoon. So many rocks and so little time to crack open them all especially when you are finding fossils. I still have a couple of my finds here.

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[Horus]

On our South and North East coasts we have Jurassic deposits that can be easily accessed especially after a few rough seas in the Winter months. On one such beach in a place called Charmouth the very first Plesiosaur fossil was discovered by a woman named Mary Anning on that particular beach, There are also large numbers of Ammonites and Belmite fossils which are squid like creatures some of which grew to a huge size. like you I have spent many happy hours on these beaches with a hammer cracking open the ‘nodules’ of rock that you find in the decaying cliffs. The surrounding material of the cliff face is usually quite soft so that the rounded nodules are easily spotted especially in the very common rockfalls that occur. When you crack one open it usually contains a hard material inside in the shape of the Ammonites.

[LovelyLadyLux]

When the daughter and I first went to the river bed it was nothing but rocks to me but soon as you can start to SEE the rocks and know what you're looking for it is like mining for gold. You can suddenly SEE the everywhere.

Great fun especially when you do find something in almost every rock you open. Mostly here it was plant leaf forms and the odd bug but they did manage to excavate an entire elasmausaur skeleton from the river bed and now have it hanging in the towns Museum. It was a great find at the time (mid to late 1980ies from memory), tons of T-shirts printed up with the skeleton and is still one of the towns main claims to fame.