505-million-year-old fossils, found by Calgary scientist, shed light about how life evolved on Earth
When a Calgary scientist examining fossils in Canada's Burgess Shale region noticed that previous researchers had only just scratched the surface of the evolutionary record, he decided acid was a better bet.
Dr. Paul Johnston, an associate professor in Earth and Environmental Sciences at Calgary's Mount Royal University, says his collection of marine invertebrates called stenothecoids were found on Mount Stephen in Yoho National Park.
However, it was his way of extracting the fossils from the rock that helped scientists learn more about the "peculiar animals."
Officials say while other scientists split up the shale to locate the well-preserved but flat specimens, Johnston used acid to dissolve the limestone they were encased in.
"Most of the Burgess Shale is shale, but there are some layers of limestone and I could see that the shells had been replaced by silica and that gave me the idea to put the limestone in acid because I know that the silica shells are resistant to acid," he told CTV News in an interview on Thursday.
"I could get them out as three-dimensional shells from this 505-million-year-old limestone."
Prior to Johnston's discovery, many researchers believed stenothecoids were an extinct group of the phylum Mollusca, which contains clams, snails and squid.
"The shell is kind of asymmetrical – it kind of has a 'sway' to it," Johnston said. "It's absolutely unique in the animal kingdom, so paleontologists were at a loss to figure out where on the evolutionary tree of life these creatures belong.
"Paleontologists thought they might be related to the phylum Brachiopoda, which are fairly rare in modern seas unless you live in New Zealand or Antarctica where they are still fairly common."
The three-dimensional fossils helped Johnston identify some key features and place the shelled creatures where they belong to better illustrate how life evolved on Earth.
"They show a number of features that we don't see in modern brachiopods or even other fossil brachiopods that we know of. This tells us about how life was evolving in the Cambrian Period – how the different forms of life were diversifying fairly quickly. We call this interval the Cambrian Explosion."
Working with Dr. Michael Streng of Sweden's Uppsala University, Johnston proposed the stenothecoids were an early off-shoot of Cambrian animals that led to the evolution of modern brachiopods.
Johnston says the stenothecoids can be compared to how bicycles evolved in modern society. At first, there were many different models of bicycles, but many of them failed and "went extinct."
"Different evolutionary groups, like the brachiopoda, show a similar pattern where you get this big variety early in their evolution, a bunch of those go extinct and we end with a few basic lineages that survive."
The fossils will reside in the collections of the Royal Tyrrell Museum in Drumheller, Alta. and the Royal Ontario Museum in Toronto.
Johnston and Streng's study can be view in the journal Acta Palaeontologica Polonica.
CTVNews.ca Top Stories
'They needed people inside Air Canada:' Police announce arrests in Pearson gold heist
Police say one former and one current employee of Air Canada are among the nine suspects that are facing charges in connection with the gold heist at Pearson International Airport last year.
Why drivers in Eastern Canada could see big gas price spikes, and other Canadians won't
Drivers in Eastern Canada face a big increase in gas prices because of various factors, especially the higher cost of the summer blend, industry analysts say.
BREAKING Toronto Raptors player Jontay Porter banned from NBA
Toronto Raptors player Jontay Porter has been handed a lifetime ban from The National Basketball Association (NBA) following an investigation which found he disclosed confidential information to sports bettors, the league says.
WATCH LIVE As GC Strategies partner is admonished by MPs, RCMP confirms search warrant executed
The RCMP confirmed Wednesday it had executed a search warrant at an address registered to GC Strategies. This development comes as MPs are enacting an extraordinary, rarely used parliamentary power, summoning one of its contractors to appear before the House of Commons to be admonished publicly for failing to answer questions related to the ArriveCan app.
Disappointment widespread over budget's proposed $200-month disability benefit funding
Advocacy groups across Canada are expressing widespread disappointment about the amount of funding earmarked in the 2024 federal budget for the long-awaited Canada Disability Benefit.
Earthquake jolts southern Japan
An earthquake with a preliminary magnitude of 6.4 hit southern Japan late on Wednesday, said the Japan Meteorological Agency, without issuing a tsunami warning.
opinion Don Martin: Gusher of Liberal spending won't put out the fire in this dumpster
A Hail Mary rehash of the greatest hits from the Trudeau government’s three-week travelling pony-show, the 2024 federal budget takes aim at reversing the party’s popularity plunge in the under-40 set, writes political columnist Don Martin. But will it work before the next election?
Woman who pressured boyfriend to kill his ex in 2000s granted absences from prison
A woman who pressured her boyfriend into killing his teenage ex more than a decade ago will be allowed to leave prison for weeks at a time.
Former Sask. massage therapist who sexually assaulted clients has day parole revoked
A former massage therapist who pleaded guilty to a string of sexual assaults has had his day parole revoked.