I recently returned from four weeks of fieldwork in southern Alberta, as part of the Southern Alberta Dinosaur Project in collaboration with Dr. Michael Ryan of the Cleveland Museum of Natural History. It was the eighth year of the project, and was without a doubt one of our best so far. We returned with the main goal of continuing excavation of the two horned dinosaur sites that we worked last year- the McPheeters Centrosaurus bonebed and the South Side Ceratopsian (SSC) quarry. The SSC is particularly exciting because lab work over the winter revealed a large part of the skull that demonstrated we indeed have a brand new species of dinosaur on our hands, so we were excited to get back into the field (Fig. 1).
Work began immediately on the McPheeters bonebed, but the prospecting finds came fast and furious, courtesy of uncanny fossil finder Wendy Sloboda. We spent the first ten days collecting a partially articulated skeleton of a small horned dinosaur – one of the smallest ever found in Alberta (Fig. 2). While in the area, Wendy also found an almost complete dinosaur nest of eggs- another very rare find.
Work started a bit late on the SSC. Last year, we collected all of the elements coming out of a rock layer that, unfortunately, was at the base of a huge hill. This year, the work began to remove the unfossiliferous rock above the skeleton (called the overburden) in order to open up a large quarry at the base of the hill (Fig. 3). The entire crew cycled on overburden removal for almost two weeks, and despite the efficient jack hammers and a whole lot of effort, we were just able to reach the top of the bone later by the end of the season. This means that we are set for a very productive year collecting the rest of this new species of dinosaurs- but this will be next summer.
We also visited the Onefour Research Station and other areas of badlands on the north side of the Milk River that we had not accessed before. On Onefour, we located a historic quarry marker placed by the Geological Survey of Canada. Although we haven’t yet confirmed the specimen taken out of the quarry, the only significant find in the area was the holotype skull of the long-frilled horned dinosaurs Chasmosaurus russelli, and I am almost certain the steel stake marks the exact location of this important find. This is significant because it allows us to put the specimen into a detailed biostratigraphic framework that our team is building for Southern Alberta, which will allow us to understand the factors linked to dinosaur faunal turnover through the Belly River Group section. We also located a good duck-billed dinosaur prospect- with only the articulated tail exposed on the hillside (Fig. 4). And Wendy also found a very nice Pachycephalosaur dome only a few meters away.
As if that were not enough, we also collected material from a new and very dense horned dinosaur bone bed that clearly pertains to another brand new species, this one with a distinctive arrangement or giant, curving spikes on the frill. We are anxious to excavate this site next season. In the last few days of the season, we were visited by Dianne Lister, President and Executive Director of ROM Governors, and her friend Janet. Dianne was in the area on vacation, and wanted to stop by to experience what it was like digging dinosaurs in the field. I showed them a few of our sites, and sat them down in the McPheeters bonebed for a short afternoon of digging- knowing that they would find something in this rich deposit. But none of us would have guessed what turned up- we have dug the site for four consecutive seasons, and collected every part of the skull and skeleton except the species-specific diagnostic ornamentation off the back of the frill. So we knew we had Centrosaurus, but we didn’t know what species, until Janet struck gold. She uncovered a beautifully preserved, piece of an adult frill that preserved the characteristically twisted parietal process that told us we have Centrosaurus apertus at this site- something we have been desperate for since we started digging the bone bed.
Our work stretched over one month, and we collected hundreds of new specimens. The details of the new finds will be revealed as the material is prepared in the lab over the Fall and Winter. With the success at McPheeters (we collected over 300 bones), an almost complete nest of eggs, the juvenile Ceratopsian skeleton, and a rich bonebed containing yet another new dinosaur, this is certainly one of our most productive field seasons. Michael and I thank Ian Morrision and Caleb Brown for working their logistical magic, and all of the students and volunteers that made this year so outstanding (Fig. 5). We look forward to getting back to southern Alberta next year!