bone man unearths the distant past

Grant Zazula takes a lot of crap in his job, but most of it is 40,000 years old. That’s because he is the paleontologist for the territorial…

Grant Zazula takes a lot of crap in his job, but most of it is 40,000 years old.

That’s because he is the paleontologist for the territorial government.

And he was eager to talk about his work when I visited him recently.

A paleontologist is a scientist who studies the forms of fossil life existing long ago in other geological periods.

In Zazula’s case, we talked about his work studying the remains that have been uncovered from the past two million years.

It’s called the Quaternary period of the Pleistocene era, and it’s darned interesting.

I have been studying the history of Gold Run Creek, a tributary of Dominion Creek in the gold fields near Dawson City, and over the years have seen the miners uncover numerous fossils while they were excavating the gravels for placer gold.

Gold Run Creek is one of the most productive creeks in the gold fields for finding Pleistocene fossils.

In fact, miners have been unearthing Pleistocene fossil specimens on this and other creeks since the earliest days of the gold rush.

I wanted to get the scoop on what these fossils can tell us about the history of Gold Run.

Zazula didn’t begin as a paleontologist, but received a degree in archeology from the University of Alberta.

He quickly realized that he was more interested in the places of the past than the people.

By the time he had commenced graduate school, he had switched to the study of ancient environments.

His first experience in the Yukon occurred in 1999, when he worked near Old Crow with archeologist Jacques Cinq-Mars on a site known as the Bluefish Exposure (not to be confused with the early human site at Bluefish Cave).

Zazula studied the plant remains from the site and painted a picture of what the environment was like at the site at the same time that people, the earliest known for the Yukon, were occupying the nearby cave.

The Klondike was an obvious next step.

The area is overlain with deposits that span at least the last two million years.

It has been very productive for paleontologists because the placer miners who work in the area uncover and save the fossils for experts like Zazula to examine.

Rather than mammoth, bison or scimitar cat, he focused on the less charismatic fossils of the Arctic ground squirrel to earn his doctorate.

But these creatures were a gold mine of information about the past environments of the Klondike region

Canada’s renowned paleontologist, Dick Harington, reported the fossil of an Arctic ground squirrel found in the Sixtymile area in 1981.

Looking like a ball of dirt and hair, the specimen was X-rayed and proved to be the complete squirrel skeleton curled up in its hibernation position.

Apparently, it died during its winter-long winter snooze almost 50,000 years ago.

Arctic ground squirrels are no longer found in the Dawson area because the shallow permafrost does not provide them the subsurface zone they need to burrow into to nest.

Zazula analyzed more than 120 squirrel nests during the completion of his PhD at Simon Fraser University. His work paid off because the little rodents were prolific harvesters, gathering up a variety of plant materials including “seeds, leaves, fruits and stems, flowers and roots of many grasses, forbs (flowering) and woody species.”

It was these specimens that the little rodents cached underground before going to sleep in the fall that enabled Zazula to reconstruct the environment of Pleistocene Klondike.

During his research, he identified 65-70 different plant species found in the squirrel burrows.

They reveal an ice-age landscape much different from that of today.

For most of the past two million years, northern North America has been covered by ice.

In fact, this has been the case for almost 70 per cent of that time period, but the north-western Yukon wasn’t encased in ice, it was part of the Bering Refugium, which spread from Siberia, across the exposed Bering land bridge, and included northern Alaska and the Klondike region of the Yukon.

The landscape was called a mammoth steppe, and it was a bounteous region for a variety of Pleistocene mammals.

The Klondike area, including Gold Run Creek, was ice free, and had much the same topography as we see today, except that it was open grassland much like the foothills of the Alberta prairies.

The climate was different.

During the most recent glacial advances, dating to 90,000 and 25,0000 years ago, the region was arid, with little snow in the winter, and little tree cover to shade it in the summer, so the ground was dry and heated up quickly in the spring and summer.

Permafrost was hidden much deeper underground than it is at present. The land supported an abundant short-grass terrain, similar to what is found east of Kluane Lake today (minus the trees).

The ice sheets weren’t far away, with the Ogilvie Mountains being covered to the north, and with a continental ice sheet that covered the area as close as Mayo to the east.

Strong winds blowing off the cold masses of continental ice picked up fine silt, known as loess, which was deposited on the countryside beyond the icy reach of the glaciers.

The landscape was dominated by three species of herbivores: bison, mammoth and horse.

None of the fossil species are found in the region today, and the bison that ranged over the land 25,000 years ago carried horns a metre across from tip to tip.

The articulated skeletons of one or possibly two mammoths were found at the mouth of Gold Run Creek and carefully excavated by archeologists a number of years ago.

The hair-covered carcass of one of the small horses was uncovered in 1993 on Last Chance Creek, a tributary of Hunker Creek, near Dawson City,

These plant eaters were hunted by a number of predators including the large-fanged scimitar cat, the American lion (larger than their African cousins) and the short-faced bear, which weighed in at 700 kilograms.

Wolves, much smaller than those inhabiting the North today, were probably minor players on the Pleistocene stage.

The glaciers began to retreat about 14,000 years ago; as this occurred, the ocean levels rose, and the Bering land bridge submerged, isolating North America from the Asian continent.

The mammals in Beringia were trapped in a rapidly changing landscape.

Trees advanced into the Klondike about 10,000 years ago, and by 9,500 years ago, Gold Run Creek probably looked much as it does today.

What about people?

We know that they lived in Blue Fish Cave 15,000 years ago, but the oldest evidence to suggest that they occupied the area around what is now Dawson City is tantalizing and frustratingly sparse.

An 11,000 year-old antler tool used for making stone implements was uncovered on Hunker Creek about 30 years ago, but there is no smoking gun, or projectile point, to put the debate to rest.

So you can see that there is a lot to be learned, and said about the way things were when glaciers capped the top of the world.

According to Zazula, the Klondike region is Canada’s gift to the world when it comes to understanding ice-age history.

I think he’s right.

Michael Gates is a local historian and sometimes adventurer based in Whitehorse.

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