Alberta paleontologists studying rare horse and camel fossils

A nondescript gravel pit in rural Alberta has been a boon for paleontologists.

At the sitein Big Stone, some 380 kilometres southeast of Edmonton,paleontologists have been finding rare fossils of prehistoric camels and horses from 1.5 to 4.5 million years ago.

By studying these fossils, researchersget a glimpse into Alberta's prehistory.

Kelsey Martin, the aggregates manager at the Special Areas Board of Alberta, noticed that in 2019 rocks they were extracting from a particular gravel bed looked different from other sites.

Martin wanted to know how old the rocks were, and contacted the Royal Alberta Museum for help.

Ancient camel fossils discovered in Alberta gravel pit

11 months ago

Duration 1:53

It may surprise you, but camels actually originated in North America before migrating to other parts of the world, and a recent discovery by paleontologists in central Alberta may lead to a better understanding of how they once lived on the Prairies.

Tempered expectations

Christina Barron-Ortiz, a paleontologist at RAM, hoped they'd be able to find some fossils, which could help date the site.

But she didn't have high expectations.

"Usually, it's really hard to find fossils in gravels," she said.

"We have visited manygravel pits across the province, and often we find nothing."

The gravel beds are what's left of ancient rivers, she said, andrivers tendto break down animal bones into tiny fragments.

The Big Stone site significantly exceeded Barron-Ortiz'sexpectations.

When they visited it in 2019, her colleague Katherine Bramble found a complete and well-preserved premolar tooth from an upper jaw of aprehistoric horse, to Barron-Ortiz's great excitement.

Martin said that day happened to be one where a lot of elected officials and administrative staff visited the site.

"Solo and beholdas they got off the bus, bothChristina and Katherine said, 'Hey, this looks unique.' And they pulled up a fossil of a horse tooth, just as everyone was coming off the bus," Martin recalls.

"Kudos to them for going and looking, because it's kind of ahundred- or a thousand-to-one odds that you're going to find material," said Duane Froese,a professor in the department of Earth and atmospheric sciences at the University of Alberta, who specializes in the ice age and past environments over the last 2.5 million years.

Froese said the Big Stone site is likely to prove a rich source of fossils.

"The fact that people found them just walking around tells you that there's probably a lot there," he said.

Bones give clues about prehistoric environment

Barron-Ortiz said the tooth they foundis anywhere between about 1.5and 4.5 million years old and fossils from that period are "exceedingly rare."

Paleontologists have been returning to the Big Stone site since 2019, and visited it twice this year. Besides finding horse bones and teeth, they also found camel bones in the Big Stone pit.

Both horses and camels evolved and diversifiedin North America about four million years ago, and disappeared about 10,000 years ago.

Prehistoric camels, like horses, migrated to Asia, wherethey evolved into modern bactrian and dromedary camels. They also moved to South America, where they evolved into modern llamas and alpacas.

So far, paleontologists have been finding mostly camel and horse bones because of how abundant they were during that period. They were grazers, well-adapted to the dry, grassy steppein Alberta between 1.5 and 4.5 million years ago, Froese said.

"We're thinking about things that are living off of probably grasslands. That's consistent with what we think about the environment at that time."

But RAM scientistshave been finding other fossils, too, that they have not been able to identify yet.

This September, for example, they a fragment of the lower jawof an unknown animal. Its teeth are broken, but the roots are still there.

"That may give us a clue to help us identify what it is," Barron-Ortiz said.

It wasn't a horse that the jaw belonged to, she said, and RAM scientists don't believe it was a camel, either. Potential candidates include peccaries, which are related to pigs, but it could also be a carnivore, she said.

"We haven't had the time to really sit down and take measurements, and start to compare it to other fossils to really get a sense of what it could be," she said.

Dating the fossils

Scientists are also working on dating the fossils more precisely.

At this time, they only have a range that covers millions of years. The fossils are too old for carbon dating, so paleontologists and geologists working on them have to use different methods.

"We've collected samples to see if we could findany pollen grains, which would give us an understandingof the vegetation that lived in the area," said Dale Leckie, a geologist with a specialization in reconstructing ancient environments.

They arelooking for remnants of volcanic ashes in the site, which would allow them to date the site more precisely.

Many volcanic eruptions have been studied, and linking ash to a particular eruption would allow scientists to determine the age of the site.

They are also considering dating the deposits using paleomagnetism. At irregularintervals, the north and south poles reverse, and this change in Earth's polarity is imprinted in the rocks.

Paleontologists intend to keep coming back to Big Stone, Barron-Ortiz said, and Martin is optimistic about the possibility of finding more fossils there.

"We definitely are planning on coming back next year," Barron-Ortiz said.

"Hopefully over the winter, there'll be more erosion, and some of the bones that are just about to be exposedget exposed."