Our research team at the Peace Region Palaeontology Research Centre recently went on an exciting field trip – a site check of the large dinosaur tracksite that we are going to be working on this summer! This dinosaur footprint site is one of the most historically and scientifically important tracksites that we have researched to date. The site was first reported to us in 2008, but these Early Cretaceous (approximately 115 million years old) footprints are part of a much longer history of the study of dinosaurs in western Canada. This was a history that was nearly resigned to being lost in a watery tomb. Life doesn’t often grant second chances. Second chances related to fossils are much more rare – once they are lost, that is usually the end of their story. We were lucky.
The First Discoveries
Dinosaur footprint discoveries in British Columbia, Canada date back to 1922-1923, when geologist F. H. McLearn first reported dinosaur footprints in the Peace River Canyon near the community of Hudson’s Hope. In the 1930s Charles Mortram Sternberg, of the famous dinosaur-hunting Sternbergs, surveyed and scientifically described the these dinosaur footprints (Note: growing up in BC and wanting to be a paleontologist at an early age, all I heard from my teachers and other well-meaning adults was “There were no dinosaurs in BC”. They were here, just not on the public radar.)
Sternberg named several new dinosaur footprint types (called ichnotaxa – fossil footprints receive binomial names just like fossil skeletons): Irenesauripus mcclearni (large meat-eating or theropod dinosaur, similar to Allosaurus or Acrocanthosaurus), Irenesauripus occidentalis (large theropod), Columbosauripus ungulatus (small theropod), Irenichnites gracilis (small theropod tracks), Gypsichnites pacensis (possibly from a large herbivorous dinosaur), Amblydactylus gethingi (from a large ornithopod, closely resembling Iguanodon), and last but certainly not least, Tetrapodosaurus borealis, the footprints of an ankylosaur. Not only was this the first scientific report of dinosaurs from British Columbia, this was the first ever report of an assemblage of dinosaur footprints from the Cretaceous Period.
The Loss To Science And Education
Field work doesn’t offer up many opportunities for scientific second chances. Field time is lost due to bad weather, funding cuts, injury/illness, etc. Field locations are lost due to incomplete records, human activity, or acts of Nature. All of these events inevitably end up with a group of scientists holding their collective heads and muttering “If only we could get back to that site. If only we had another chance.”
Sternberg’s localities along the Peace River Canyon are a big deal science-wise, so much so that they were designated as a Provincial Historic Resource in 1938. It is the go-to locality for any research involving Early Cretaceous (approximately 100 million years ago) footprints…or at least it should have been the go-to locality. Construction of two hydroelectric dams along the Peace River Canyon resulted in the creation of a reservoir (now called Dinosaur Lake). When the second dam went online in 1979 the filling reservoir flooded Sternberg’s type localities. A large salvage operation was led by Dr. Philip Currie in 1976 – 1979, then of the Provincial Museum of Alberta (now the Royal Alberta Museum). Salvage is a kind word: this operation was palaeontological triage, saving what footprints and data the crew could in the short amount of time they had. It was a commendable effort. Anyone who has done field work in the northern parts of the provinces knows that the field seasons are short and fraught with foul weather and logistical difficulties.
Research has since been conducted on the footprint types that Sternberg named, but unfortunately this work is based on the scant information required for publishing footprint descriptions at the time. There was no opportunity to recheck Sternberg’s sites to update the research he did in the 1930s, as they remain entombed under the reservoir.
The Second Chance
In 2008, Dr. Richard McCrea and I received a report of a new dinosaur footprint site near Hudson’s Hope. A short visit to the site by Dr. McCrea in 2008 confirmed that the exposure was of the same rock layers from Sternberg’s Peace River Canyon localities. The site was originally estimated at 1000m2, and unlike many of the dinosaur footprint sites in northeastern British Columbia (we work in the foothills of the Rocky Mountains, so most of our rock layers have been tilted from horizontal to vertical), this new site was easily accessible and flat. This footprint site is the closest we’ll ever get to revisiting Sternberg’s 1932 localities. We were given a second chance.
On April 22 Rich, our field crew, and I did a site visit to this new tracksite – we’re temporarily calling it the Williston Lake Tracksite. Our new estimate of the area of the track surface is 6000m2. We won’t know for sure how many footprints are preserved until we uncover the entire surface, but our initial surveys show that there is at least one footprint per square meter, so we know that we are dealing with potentially thousands of dinosaur footprints. That noise you hear is very excited science-y squealing.
Little has changed on the tracksite since the 2008 visit. What we did notice were that there were a few ATV tread marks on the soil covered parts of the site, so we know that at least one person has driven a quad over the track site. Thankfully the joyride doesn’t appear to have done any damage to the exposed footprints.
The Dinosaur Footprints
Here is a shot of the entire tracksite taken from a helicopter in 2008 (photo credit: R. T. McCrea). There are footprints exposed in the lower, black-outlined area. The rest are waiting to be uncovered.
We did a couple of small test clearings up in the covered, yellow outlined area, and saw the same types of footprints in the same numbers as in the exposed area. One of the large meat-eating dinosaur footprints from the test clearing of the covered area.
We were able to see many of the footprint types that Sternberg had named in 1932. There were many footprints and trackways of large theropod dinosaurs, Irenesauripus mcclearni.
There is a lot of moss and other vegetation growing on the footprint surface. One of our favourite footprints is an Irenesauripus with moss filling in the digital pads. We jokingly call it the Mossy-pod.
We also saw a few footprints from medium-sized and small-sized theropods. We need to clear off more of the track surface before we’ll have all of the data required to put a name to these footprints.
This medium-sized theropod footprint is very shallow, but the tips of the toes pressed into the sediment deep enough to be visible.
My specific research interest is in bird footprints from the Early Cretaceous, so I was crawling all over the rock looking for small footprints. I did find a small theropod footprint, but it is not well-preserved. Once we give the entire rock surface a thorough brushing we’ll have a better shot at finding tracks and trackways of small animals.
We also saw several footprints from the large plant-eating ornithopods, with the footprint name of Amblydactylus gethingi. While the herbivorous dinosaurs that made these footprints could walk on their hind limbs, the footprint evidence shows that they spent a great deal of time using both their hands and feet to walk.
We uncovered a hand print of Tetrapodosaurus borealis (from an ankylosaur). The light was not the greatest for taking pictures of footprints that have enough contrast to see all of the details, but five fingers of an ankylosaur hand were visible enough for identification (fingertips highlighted).
Thanks to generous private grant and cooperation from local businesses, from June to August we will be able to conduct research on this footprint site. The site has to be cleared of vegetation and the loose dirt and swept clean. We then have to examine every square centimeter of surface and locate all of the tracks and trackways. The entire track surface will be photographed so that we can construct a 3D-digital model of the track surface that can be studied and shared with other track researchers. A 1 meter x 1 meter grid will be drawn on the track surface, and all of the footprints will outlined in chalk, mapped, and traced onto plastic sheets. Noteworthy trackways showing new footprint types or interesting behaviors will be replicated. After all of that work is completed, we’ll rebury the site to keep it safe from vandalism, theft, and other anthropogenic activities that are damaging to dinosaur footprints.
What will be our science objectives? We want to update and include more details to Sternberg’s original descriptions of all of these footprint types. We have better imaging tools now than were available in the 1930s, and we will publish these updated descriptions and images so that they are widely available to vertebrate ichnologists (Sternberg’s 1932 paper is not easy to find online). This will be a large publication, and given the heavy research focus on Early Cretaceous footprints from around the world, it is a necessary publication.
One of the great side benefits of doing research at an accessible site is the potential for its inclusion in science education and communication. Once the initial research is conducted, this site would be ideal for a future dinosaur footprint interpretive center and educational tours. We are working with local communities to get support for this initiative, and to foster a sense of pride and responsibility for their local natural heritage. My personal goal is to make sure no child in elementary school is ever told again “There are no dinosaurs in BC”. Our fossil heritage should not be our province’s best kept secret.
For anyone who is interested in seeing updates on this summer’s field work, when I have Internet access I’ll post updates at birdsinmud.blogspot.com, and on my Twitter @Lisavipes.
Sternberg C. M. 1932. Dinosaur tracks from Peace River, British Columbia. National Museum of Canada Bulletin 68:59-85