The discovery of the skull of a long-extinct breed of muskox south of Dawson City could help scientists understand more about why the large beasts disappeared.
A rare, nearly intact skull of the North American helmeted muskoxen, Bootherium bombifrons, was uncovered by placer miner Stuart Schmidt on Sept. 11.
Schmidt was working on Canyon Creek, a tributary of Little Blanche Creek in the Indian River valley.
Schmidt says he was digging drainage for monitoring a section of the creek when he spotted a horn sticking up out of the gravel.
It’s not uncommon for miners in the area to find bits of bone, he said.
“I grabbed a hold of it with one hand as if its going to coming out of the ground easily but it doesn’t come up.”
Schmidt grabbed hold of the horn with both hands and pulled.
What emerged out of the ground was a set of intact horns and most of the skull.
Schmidt sent a picture to Yukon paleontologist Grant Zazula.
What followed were “several enthusiastic emails in quick succession,” Schmidt said.
Zazula was understandably excited.
The horns are nearly fully intact as is the thick pad of keratin that sat on top of the animal’s head and gave it its name, he said.
“These were animals where males were probably having these really aggressive fights and battering their heads in conflict. So they evolved to have these incredible horn sheath helmets on the top of their heads. It just looks really awesome.”
The last time a helmeted skull this intact was found in the North was when a placer miner near Fairbanks uncovered one in the 1920s.
Between the 1920s and now “there’s maybe been a handful of their bones found in Yukon and Alaska and none of them are very well preserved,” he said.
The helmeted muskox are different from the modern muskox that roam the North today, Zazula said.
The ancestors of helmeted muskox travelled from Eurasia over the Bering Land Bridge, and into North America around one million years ago.
Ancestors of the tundra variety, the ones we are more familiar with today, travelled the same route around 200,000 years ago.
Helmeted muskox once covered all of North America, and were more common in the south, whereas the tundra muskox were more restricted to the North, Zazula said.
Having a preserved helmeted skull will help scientists understand more about the animal, he said.
It will be carbon dated and scientists will take detailed measurements.
“We can actually make some measurements on it and then compare it to other populations across the continent to look at variability in body size and all that,” Zazula said.
The fossil will also be used to help scientists trying to figure out what life was like for the helmeted muskox before it went extinct.
The tundra and the helmeted muskox are genetically different animals but they lived in the North at the same time.
“They were living on the same landscape,” Zazula said. “How did they do that?”
Zazula said his working theory is that the two animals probably ate different diets and therefore used different parts of the landscape.
Last summer a student from the University of Western Ontario came North to study the pieces of the helmeted muskox that the Yukon had at the time.
She’s looking at the chemistry of the bones “to basically try and get an idea of what they were eating,” Zazula said. This latest find will be “another piece of the puzzle.”
Understanding the helmeted muskox’s diet may also provide a clue to why they ended up extinct while the tundra variety thrived, he said.
“Maybe it’s an issue of the dietary sources getting wiped out at the end of the ice age and caused extinction of one of the species and allowed for the other one to persist.”
Zazula said the work by Yukon placer miners to collect any specimens they find is key to understanding Yukon’s history.
“Without placer mining none of these discoveries would be made and our knowledge of the ice age, of Yukon, would be almost nil,” he said. “All summer they’re out digging through the frozen ground and that frozen ground is the ground that was laid down during the ice age.”
Schmidt, who has worked in mining for about 65 years said “It feels good to save these things.”
The Klondike Placer Miners Association, the Tr’ondëk Hwëch’in First Nation and Yukon government all spoke with each other when the skull was found, said Lee Whalen, a heritage officer with the Tr’ondëk Hwëch’in.
All sides are currently working on official policies for how finds like this will be communicated and who will own the object, Whalen said.
In 2016 the First Nation inacted its own Heritage Act. The Yukon government also has its own legislation.
“At this point we all kind of take on a role to take care and be stewards of these things. I think ultimately that’s how it’s going to work in the future too,” he said.
“We all want these objects to be safe, to tell a story and to teach and be a learning tool. As long as that’s happening then we’re all in a good space.”
The skull will be stored at a Yukon government facility.
Zazula said the skull is going to be taken to the Tr’ondëk Hwëch’in offices to show to the community.
Aside from the scientific benefits, Zazula said finding a skull like what Schmidt uncovered will help teach members of the public about Yukon’s history.
“It’s nice to have an impressive looking skull for kids to see, for the public to see and learn about,” he said.
“A broken leg bone isn’t that cool to look at, but an awesome skull with huge horns sticking out, people love that kind of stuff. I love that kind of stuff.”
Contact Ashley Joannou at firstname.lastname@example.org