By Andrew Knapp
The rather grandly named Dinosaur Provincial Park is a world-famous geological site in Alberta, Canada. It is perhaps the best place on Earth to find the remains of dinosaurs, which has earned it the status of UNESCO World Heritage Site. In Calgary Airport, there are large floor-to-ceiling posters for Alberta’s tourist hotspots – the Rocky Mountains, Downtown Calgary, and Dinosaur Provincial Park. The Dinosaur Provincial Park (DPP) poster states that it is ‘like nowhere else on Earth’, but this is not strictly true. The geography of DPP is what makes it such a special place for finding fossils, and that is what it has in common with many of the world’s richest dinosaur sites, from Argentina to Mongolia. These unusual places have a habit of all looking very similar indeed, but DPP is the richest of all.
Fossils can be both surprisingly common and astonishingly rare. To survive the ages, an animal or plant needs to die in exactly the right place, where it will lie undisturbed and be buried quickly. Its remains must not be forced too deeply, nor eroded away too soon.
The fossil-rich rocks that form southern England’s famous Jurassic coast (another UNSECO World Heritage Site) were deposited in oceans – ideal conditions for forming and preserving fossils. Locations on land, however, where fossils can form, are few and far between. Animals that live on mountains won’t become fossils. Nor will the vast majority of those that live in forests or open plains. But those animals that live and die in and around estuaries, or other places where sediment deposition is high, have a better chance of being fossilised. They are also much more likely to be found.
To dig down just anywhere in an attempt to find fossils would be a fruitless task. This is why palaeontologists must rely on a process that is at odds with the preservation of fossils – erosion. At certain places on the surface, erosion removes sediment and exposes new fossil deposits that were previously inaccessible. It is at these places that efforts to find fossils are concentrated; places like DPP. The majority of sediments in DPP are so soft that they are eroded easily by flowing water; so new fossils are exposed frequently and are easy to excavate.
The Red Deer River flows through DPP, and does the work of countless mechanical excavators every year in exposing underlying rocks. Without the river, these sediments would remain deep beneath layers of grass, soil and overlying layers of rock (and mosquitoes, of course). This is why so many of the best fossil sites look alike; erosion is the palaeontologist’s friend.
Southeastern Alberta is a seemingly endless, rolling prairie sliced through by deep, meandering river valleys. These valleys are the Badlands, impassable by wagon, infested with bandits and mosquitoes, and useless for agriculture. At least, that’s how they were when European settlers first arrived. These days they are considerably safer and more settled (but the mosquitoes remain).
75 million years ago during the Cretaceous Period, the area that is now DPP was a tropical river estuary on the edge of a shallow sea that bisected the North American continent. The area was home to a hugely diverse collection of dinosaur species. Beginning with the discovery of Albertosaurus by Joseph Tyrrell in 1884, Alberta has become a hotbed of dinosaur discoveries, today conducted largely by the Royal Tyrrell Museum in Drumheller. The Tyrrell is now one of the World’s greatest dinosaur museums. In August 2016 I paid a visit to DPP and the Tyrrell along with a group of 15 undergraduates from Queen Mary, University of London (QMUL) as part of their third-year module, Species And Their Relationships: Dinosaurs to DNA.
The terrain is still as tough and unforgiving as it was for those 19th century explorers, but the scenery is starkly beautiful, and the on-site accommodation has air conditioning and dishwashers. It hardly feels like fieldwork when you have that to come back to after a long, hot day.
Running at a depth of up to 100 metres, DPP is a maze of sandstone and mudstone hills and coulees (deep, dry ravines). DPP is so rich in dinosaur fossils that you are literally tripping over them. The park is so large that only a small part of it can feasibly be explored at any one time. It is entirely probable that a just short walk from the path will lead you to an area that no human has set foot in years.
Hadrosaurs (duck-billed dinosaurs) make up about 80% of all dinosaur remains in the park, and are so common that palaeontologists typically ignore them, unless they are unusually rare or particularly complete. In 2014, one such specimen was discovered by QMUL students; the tip of a skull exposed on a remote hillside turned out to be a small part of an almost-complete hadrosaur.
Fieldworkers from the museum have spent the past two summers removing a large chunk of the hill. The fossils, and the rock immediately surrounding them, are then wrapped in sack-cloth soaked in plaster of Paris, which forms a protective jacket. This year our students arrived in time to help with this process, and spent several hours jacketing one of the larger blocks for transport. Science so rarely resembles pre-school as it does in Palaeontology fieldwork.
The smaller material we collected was taken to the DPP field station, where the students prepared, identified, and added it to the Tyrrell’s research collections. Here they will remain in perpetuity alongside the other dinosaurs and fossils of freshwater fish, turtles and crocodiles. One student’s find, a paddlefish skull, was particularly exciting for the museum, as it was one of the most complete they’d ever seen from the park, and helps fill an important gap in their collection. A small find, perhaps, but an important link in helping us better understand the history of life on our planet.