Hay River vertebrate fossil recovery

Regions: South Slave Region

Tags: fossils, paleontology, specimen collection

Principal Investigator: Henderson, Donald M (1)
Licence Number: 15345
Organization: Royal Tyrrell Museum of Palaeontology
Licensed Year(s): 2013
Issued: Sep 27, 2013
Project Team: James McCabe (Senior Technician, Royal Tyrrell Museum of Palaeontology), Christopher Capobianco (Technician, Royal Tyrrell Museum of Palaeontology)

Objective(s): To excavate the body fossil(s) and their careful packaging for removal and travel; and to make latex rubber peels of the fossilized trackways left on a fine-grained limestone.

Project Description: The objectives of this research project are to: 1) excavation of the body fossil(s) and their careful packaging for removal and travel; and 2) make latex rubber peels of the fossilized trackways left on a fine-grained limestone. If the quality of the tracks merits it, the rock slabs hosting the tracks may be removed for safe-keeping and public display.

The fossil will be collected using standard paleontological techniques. First the areal extent of the specimen will be determined by carefully removing some of the covering rock. Any exposed bone will be treated with a dilute glue to hold it in place. It is anticipated that the soft limestone hosting the fossil will be easily cut with a rock saw. Once the extent of the fossil is known, a series of cuts will be made with the saw to define a "box of rock" enclosing the specimen. The rock outside of this block will be removed to provide working space for the next stage of the process. A plaster and burlap/fibreglass jacket will be constructed over and around the block to hold the block and its contents together. Using chisels and hammers the box will be gently separated along an existing plane of weakness in the rocks layers beneath the specimen. A sufficient thickness of rock will be kept beneath the specimen to ensure a strong and stable platform that can be moved. The block will then be removed from the site. Depending on the nature of the rock (crumbly and fragile, or not), another layer of plaster and burlap may be applied to the entire exterior surface of block. Some reinforcing in the form of 2x2 or 2x4 timbers may be embedded in the plaster jacket to improve its stiffness. Based on fossil finds from elsewhere in the world, it is expected that the fossil specimen will be about 1-1.5m long and about 20cm wide if it is complete, and the block hosting the specimen will extend around it for about 10-15cm. Removal of the fossil should take no more than two days (weather permitting).

The trackway(s) will be recorded by painting them with several layers of latex rubber. These initial layers will then be backed up with further latex layers re-enforced with cheese-cloth, until about 8-10 layers have been applied. Finally, a rigid layer composed of plaster and fiberglass will be applied to give support and protection to the latex layers. All of this layered structure will be lifted off in one go. It is anticipated that the latex layering process will take at least three days (temperature dependent) to complete.

Members of the Hay River Museum Society will be assisting with various stages of the collection process. Displays of the fossil remains, along with interpretive material, will be made at the local museum in Hay River and also in the Prince of Wales museum in Yellowknife.

Presentations can/will be made to the people of Hay River/Yellowknife highlighting the importance of the finds. If the track-bearing rocks are removed, they can go on display at the local museum. A replica (derived from the latex peel), or even original tracks could also go on display in Yellowknife. The body fossil, if it turns out to be what we think it is, would go on display in Yellowknife. If the state of preservation of the fossil allows it, a cast of the fossil could also be made to go on display in Hay River and also at the Tyrrell Museum in Drumheller. Interpretive displays would be made by Tyrrell Museum staff to enable the public to understand and appreciate the finds and their scientific importance.

The fieldwork for this study will be conducted from September 28, 2013 to October 13, 2013.