Dr. Don Brinkman, Dinosaur Research Program, Royal Tyrrell Museum of Palaeontology
The 1999 field season was one of our most ambitious and productive Field Experience programs yet. As well as supporting research projects by the Royal Tyrrell Museum, we hosted scientists from Norway, Argentina, Denmark and the United States. Material collected includes some of the finest specimens yet recovered from Alberta, and will support both exhibit and research projects for future students and researchers.
One of the prize specimens of the season was the complete skeleton of a large carnivorous dinosaur. Only the tips of the snout and tail were exposed when first found. However, the quarry quickly grew into an enormous excavation requiring nearly two months of work. The specimen was preserved in a modified "classic" death pose, with the tail arching over the body, and the head rolling over and back to lie upside-down above the ribcage. Owing to the size and unusual position of the specimen, the tail was removed in a separate jacket, leaving the rest of the body in a massive (2.5m x 1.5m x 1m) block. Thirty-seven layers of plaster and burlap were applied - making this one of the thickest (12 to 14cm), and at six tons, one of the heaviest RTMP jackets collected.
Moving a jacket of that size in the badlands is a major undertaking. Amoco Petroleum Canada and Joanne Trucking Ltd. donated time, equipment and funds to help us to get the specimen out of the valley and to the Royal Tyrrell Museum of Palaeontology.
It took four days to open the jacket on the biggest block when preparation on the specimen began in mid-September; since then, work by two technicians has revealed an exquisitely preserved skull and gastralia (belly ribs) that are in place.
Other field work in the park included excavation of Bonebed 138 as part of an ongoing study of horned-dinosaur bonebeds. This quarry, which can be seen from the overlook at the park entrance, is the oldest such bonebed known in the park. We now have enough material to demonstrate that the ceratopsian dinosaur at this site is a new species similar to Centrosaurus and Styracosaurus, which occur in overlying beds. The main difference is horn structure; instead of the short hooks seen on Centrosaurus or the long spikes of Styracosaurus, the new animal has rosettes of short, needle-like bony elements. Hundreds of individual bones have been collected - they are being prepared at the Field Station by volunteer preparators as part of the museum's volunteer preparation program. We hope to have a complete composite skeleton when the work is done.
As in past years, we continue to prospect the park for new specimens; 1999 was the year of the turtle. More turtle specimens, each more completely preserved, were found than had been the case for many years. Prize specimens include a nearly complete large skull and six complete shells representing five different kinds of turtles. Two specimens are currently being prepared, including a large soft-shelled turtle shell found near the tyrannosaur skeleton. It is a smaller individual of Aspideretoides splendidus, one of the larger soft-shelled turtles in the park. This specimen will help us determine growth rates and differences between two closely related species. Preserved upside down, preparation of the second specimen has revealed the well-preserved, complete skull of a very large soft-shelled turtle. Awaiting preparation is a large carapace and plastron of a group now thought to be closely related to marine turtles.
One non-turtle specimen located last summer was a horned dinosaur, represented by a scattered, but associated skeleton. Several vertebrae, a pelvic element and a limb bone were identified within a small area. This specimen will be excavated during the 2000 season.
Other important work in Dinosaur Provincial Park last summer centred on leaving permanent, on-site records of quarries. Documentation of quarry sites is an important part of paleontological research - a record of what fossil was found where, when and by who enhances scientific value and potential of specimens. Usually documentation consists of a land description or GPS (Global Positioning System) coordinates. However, Dinosaur Provincial Park's badland topography and high erosion rates make finding previously excavated sites near-impossible. Starting in the mid-1930s, iron pipes with brass data-bearing heads were cemented into holes drilled into quarry floors. As we excavate our own quarries, we are responsible for continuing the quarry-staking tradition. Good progress was made as we staked a half-dozen quarries last summer.
A related project is the search for and identification of "mystery quarries" - unstaked sites excavated long ago. Examination of garbage such as newspapers, tin cans and bottles left on site can provide information on the date of an excavation. This, when compared with field notes, historical photographs, and other data, can result in accurate documentation of important historical localities. One such site rediscovered this summer is the 1936 quarry of the first-known specimen of the toothless, small theropod, Caenagnathus; newspaper fragments dating from a 1936 Calgary Daily Herald found near a small cut in an outcrop led to the site's identification.
Here is an update on the Myledaphus specimen collected in 1998. One of the prize finds of the 1998 field season was a complete skeleton of the freshwater ray, Myledaphus. We had hoped that the elements of the jaws and braincase were also preserved as part of this exquisitely preserved fossil. In order to establish this, Royal Tyrrell Museum of Palaeontology technician Ken Kucher had the specimen x-rayed at the Drumheller General Hospital. Large upper and lower jaws could be seen, along with what appears to be the braincase. With a better idea of what to watch for, Kucher started preparing the specimen, using a microscope and pin tools to remove the sandstone grain by grain from the delicate fossil. As the slow, painstaking work proceeds, denticles and complex shapes are emerging; we hope to soon see evidence of the shape of this animal that is so abundantly represented by isolated teeth.
