Piecing together Yukon’s dinosaurs, one fossil at a time

Truckloads of mammoth and bison bones arrive at the Yukon palaeontology unit every year, dug up by placer miners, adding to an impressive collection of Ice Age specimens.

Truckloads of mammoth and bison bones arrive at the Yukon palaeontology unit every year, dug up by placer miners, adding to an impressive collection of Ice Age specimens.

But the further back in time you go, the less evidence there is. When it comes to the age of dinosaurs, you can hold the entire collection in the palm of your hand.

That’s not to say that dinosaurs weren’t here. They just haven’t been found yet.

In the summer of 2010, Carleton University paleontology student James Campbell was examining the shale along the banks of the Road River, a tributary of the Peel east of Eagle Plains.

As an intern with the Geological Survey of Canada, Campbell was collecting microfossils to determine the age of the rock exposed on a cliff side when his trained eye was drawn to a larger fossil sitting among the shale.

Campbell’s specimen doesn’t look like much, to be honest: it’s rough and chipped and multicoloured. But he knew immediately it was a vertebra, a section of spine, most likely from a fish or a marine reptile.

How did he narrow it down on the spot?

Previous mapping had dated the rock in the area to the later part of the early Cretaceous period. At that time, much of northeast Yukon was underwater.

The Western Interior Sea covered Eagle Plains, the Peel watershed, Alaska’s North Slope, the Mackenzie Delta and most of the Great Plains of North America.

Knowing this, any specimen found from that era would likely be from an aquatic species.

Upon initial inspection, fish was ruled out.

“I was quite sure it was a marine reptile,” said Campbell. “Fish vertebrae are concave, this one had relatively flat surfaces.”

Further examination narrowed it down to some kind of Elasmosaur, a family of long-necked, paddle-finned reptile.

“It looks like what you’d imagine the Loch Ness monster to be,” said Campbell.

After the find, Campbell returned to Ottawa to finish his degree and didn’t have time to write up his findings until 2013.

At that point, Yukon paleontologist Grant Zazula brought a second fossil into the picture.

The vertebrae of an Ichthyosaur, a dolphin-shaped marine reptile, was discovered by a fur trapper named David McDonald near the Beaver River in southeast Yukon in 1998, and sat in Yukon’s collection for 15 years.

The Ichthyosaur fossil is polished by weather and time, and has a distinctive depression in the centre.

Finding the source of the Beaver River fossil proved to be more challenging, because the rock in that area comes from the Triassic period, at least 100 million years earlier.

With the help of University of Alaska Fairbanks paleontologist Pat Druckenmiller, an expert in marine reptiles, they figured out that the fossil didn’t match its surroundings, chronologically speaking. A Triassic Ichthyosaur would be tiny.

“There’s no way it could be from that period, it’s way too big,” said Zazula.

They found that the specimen is also of the late-early Cretaceous, the same as Campbell’s fossil.

An outcrop of Cretaceous rock was located about four kilometres upstream on the Beaver, and that is considered the origin point. It’s thought that either the river or glacial action moved the fossil to the spot it was found.

Putting all these pieces together can help scientists draw some conclusions about life at that time.

During the late-early Cretaceous period, in the Albian age (113 to 100 million years ago) the Western Interior Sea extended south to what is now Texas but did not connect to the Gulf of Mexico. This means these large marine reptiles entered into the sea from the north, the Arctic Ocean, and would have lived and evolved in Arctic waters during that era.

Zazula hopes these discoveries will tweak people’s thinking about evolution in the High Arctic. “You can have incredible biodiversity at high latitudes,” he said.

Campbell, Zazula and several other scientists submitted their findings to the journal The Canadian Field Naturalist, which will hopefully spark some interest in other fossil-finding expeditions in the territory.

As it is, the Yukon is largely unexplored. Campbell’s find may change that. “This is how areas get opened up for research, a scratch at the surface,” said Zazula. “Once you get people with rock hammers on the ground, that know what they’re looking for, I think more stuff like this will be found.”

Contact Ian Stewart at

istewart@yukon-news.com

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Premier Sandy Silver, left, and Chief Medical Officer Dr. Brendan Hanley speak during a COVID-19 update press conference in Whitehorse on July 29. Silver urged “kindness and patience” during the weekly COVID-19 update on Oct. 21, after RCMP said they are investigating an act of vandalism against American travellers in Haines Junction.
(Alistair Maitland Photography file)
COVID-19 update urges “kindness and patience” for travellers transiting through the territory

“We need to support each other through these challenging times”

Whitehorse Correctional Centre officials have replied to a petition by inmate Charabelle Silverfox, who alleges she’s being kept in conditions mirroring separate confinement, arguing that her placement isn’t nearly as restrictive as claimed. (Joel Krahn/Yukon News file)
Inmate not being kept in restrictive confinement, WCC argues in response to petition

Whitehorse Correctional Centre (WCC) officials have replied to a petition by an… Continue reading

wyatt
WYATT’S WORLD

Wyatt’s World for Oct. 23, 2020

Kwanlin Dün First Nation chief Doris Bill holds up a signed copy of the KDFN <em>Lands Act</em> agreement during an announcement at the Kwanlin Dün Cultural Centre in Whitehorse on Oct. 20. Under the new act, called Nan kay sháwthän Däk’anúta ch’e (We all look after our land) in Southern Tutchone, KDFN will be able to allot citizens land to build their own houses on, for example, or to use for traditional activities. The First Nation will also be able to enforce laws around things like land access and littering. (Crystal Schick/Yukon News)
Kwanlin Dün First Nation’s Lands Act comes into force

The act gives the First Nation the authority to manage, protect and enforce laws on its settlement lands

Two doctors in Watson Lake say they are at risk of losing their housing due to a Yukon Housing Corporation policy that only allows one pet per family. (Wikimedia Commons)
Healthcare workers in Watson Lake say housing pet policy could force them to leave

The Yukon Housing Corporation has threatened evictions for having more than one pet

Yukonomist Keith Halliday
Yukonomist: Irony versus Climate

Lately it seems like Irony has taken over as Editor-in-Chief at media… Continue reading

Evan Lafreniere races downhill during the U Kon Echelon Halloweeny Cross-Country Race on Oct. 16. (Inara Barker/Submitted)
Costumed bike race marks end of season

The U Kon Echelon Bike Club hosted its final race of the… Continue reading

Smartphone showing various applications to social media services and Google. (Pixabay photo)
National media calling for level playing field with Google, Facebook

In Canada, Google and Facebook control 80 per cent of all online advertising revenues

Education Minister Tracy-Anne McPhee, right, before question period at the Yukon legislative assembly in Whitehorse on March 7, 2019. The Yukon government announced Oct. 19 it has increased the honoraria rates for school council members. (Crystal Schick/Yukon News file)
Honoraria increased for school council members

Members of school councils throughout the territory could soon receive an increased… Continue reading

Triple J’s Canna Space in Whitehorse on April 17, 2019, opens their first container of product. Two years after Canada legalized the sale of cannabis, Yukon leads the country in per capita legal sales. (Crystal Schick/Yukon News file)
Yukon leads Canadian cannabis sales two years after legalization

Private retailers still asking for changes that would allow online sales

A sign greets guests near the entrance of the Canada Games Centre in Whitehorse on June 11. The city announced Oct. 16 it was moving into the next part of its phased reopening plan with spectator seating areas open at a reduced capacity to allow for physical distancing. (Crystal Schick/Yukon News file)
CGC reopening continues

Limited spectator seating now available

During Whitehorse city council’s Oct. 19 meeting, planning manager Mélodie Simard brought forward a recommendation that a proposed Official Community Plan amendment move forward that would designate a 56.3 hectare piece of land in Whistle Bend, currently designated as green space, as urban residential use. (Courtesy City of Whitehorse)
More development in Whistle Bend contemplated

OCP change would be the first of several steps to develop future area

asdf
EDITORIAL: Don’t let the City of Whitehorse distract you

A little over two weeks after Whitehorse city council voted to give… Continue reading

Most Read