Fossil find ‘upsets old theory’ of evolution

A species of fish that lived 350 million years ago has been discovered in Nova Scotia, casting new light on a little-understood time period.

The discovery was made in 2015 by Jason Anderson, a vertebrate paleontologist at the University of Calgary, at Blue Beach, N.S., and announced Wednesday.

Chris Mansky, fossil researcher and curator of the Blue Beach Fossil Museum, says Anderson located the skull of the early Carboniferous fish and was able to compare it to the family tree of better-known relatives of the fish.

Mansky says the research of Anderson and his team show the fish’s lineage appears to be a survivor of the Devonian extinction, which contradicts the notion the extinction wiped out that group.

The species — Avonichthys manskyi — was named after the nearby Avon River and for Mansky, in honour of his years of collecting the fossils of Blue Beach.

The findings were published Wednesday in the United Kingdom’s peer-reviewed Royal Society Open Science journal.

Mansky said the fish is unique, and the discovery means that researchers may start looking at evolution differently.

“It paves the way for future researchers. It gives us new theory and it upsets the old theory,” he said.

“The old politics of the Devonian extinction is very much in debate. This is essentially a road map of new opportunities for young researchers who can work at this for many years ... The actual shape and patterns of evolution are not so clear.”

Anderson said he came across the specimen by chance during a stroll on Blue Beach.

“There’s nothing extraordinary about that moment at all. I was just literally walking along looking at the ground, kicking rocks, and I found one that was the shape of a bone. I didn’t even know it was a fossil,” said Anderson.

“It wasn’t until a few months later that I actually put it under a microscope.”

Anderson said there are many lingering questions, including how many of these fish species survived the extinction.

“We need to get a better idea of what other fish lived at that time, and in other places at the same time, and that will tell us more about how severely vertebrates were impacted by the mass extinction.”

He said that research has already taken him back to Blue Beach.

The fossil was found on the Bay of Fundy’s Minas Basin, which has the highest tides in the world. The sea has eroded into the shoreline, uncovering 350-millionyear-old fossils.

“This highly dynamic environment, over four kilometres in length, creates unique opportunities for discoveries that would otherwise be very difficult to make,” said Mansky. “Nature does the digging here.”