Ancient tree stump found in Edmonton's river valley

A 70-million year-old tree stump is part of temporary exhibit in the University of Alberta's Paleontology Museum.

Katie Willis - 02 January 2020

An ancient, petrified tree stump was spotted in Edmonton's river valley in November by a citizen scientist. Significant in terms of both its size and rarity, the specimen is thought to be from the Horseshoe Canyon Formation-placing its age between 67 to 74 million years.

"Natural history objects, like rocks and fossils, help us explain why our region looks the way it does today and why we have the natural resources that we do," said Lisa Budney, collections and museums administrator in the Department of Earth and Atmospheric Sciences. "More importantly, studying rocks and fossils helps us study climate change and extinction events to predict how the geological, climatic, and environmental changes we see today may impact us into the future."

And this ancient tree stump is no exception. The stump was removed from its location in Edmonton's river valley using a winch on a specialized boat operated by Northern Underwater Systems, a division of Canadian Dewatering LP.

Now in its new home in the University of Alberta's Paleontology Museum, the stump is part of a temporary exhibit from January to August 2020, following cleaning and conservation efforts. "A pollen analysis will be done by examining the rock below the stump to narrow down its age. Thin sections of the wood will be used to assist in species identification," added Budney.

The stump was spotted by local citizen Mike Lees who was paddling down the North Saskatchewan River in mid-October with a friend. Lee's friend Jeff Penney worked with UAlberta experts and staff at the Royal Tyrrell Museum of Paleontology to ensure the specimen would be collected in compliance with the Archaeological and Palaeontological Research Permit Regulation. Citizen scientists like Lees and Penney are an important part of the scientific community-especially when it comes to the study of natural history, Budney explained.

"Citizen scientists can draw researchers' attention to natural history objects that may be here today, but gone tomorrow. Fossils in river valleys break down, or are buried, due to erosion and ground movements. In this case, it's likely the stump would be displaced by the river freeze and thaw and end up at the bottom of the river, or moved somewhere downstream, or buried during a river bank collapse."

The stump is now on temporary exhibit in the University of Alberta's Paleontology Museum, open to the public Monday through Friday, 8 a.m. to 4 p.m.