Excavation of British Columbia's First Complete Dinosaur (II)
season of the second dinosaur excavation was destined to resume
success of the test pit in the previous year. This new dig season was
a bit more ambitious now that the palaeontologists knew this was a
warrantable excavation producing a number of wonderfully preserved
This year's excavation would last from before the middle of June until the middle of September and more than half of this time would be spent on the physically punishing process of overburden removal. This was due to the fact that the dinosaur was located near the base of a steep hill. Every square metre the palaeontologists pushed into the hill meant that eight or more cubic metres of overlying rock had to be removed using just picks and shovels. At the end of this season the pit was over 10 metres wide by at least three metre deep. With variations in the height of the hill this meant that approximately 250m3 of overburden was cleared above the bone-bearing horizon.
One of the reasons so much space was cleared was to allow room for the palaeontologists to follow any major bone elements they might encounter. It is terribly frustrating to find the tip of a large metre-long bone on the edge of a several metres high hillside. Also, the bone at this site was eroding out along a 10 metre wide front which pretty much dictated the dimension of one side of the pit. Some of these bones were in areas in danger of slumping and had to be dealt with as soon as possible.
A group of cadets from Fort St. John camp out in the museum the night before coming out to the dig site to help with overburden removal. This exercise added greatly to the PRPRC's ability to move a lot of rock quickly from above the bone layer.
There is always someone with a camera when things like this happen.
The careful work begins in the expanded pit.
A brand new tent that had just been set up at the camp area suffers from the curiosity of a bear. No one had been in the tent and no gear was present either. The mess tent a couple hundred metres away with bins full of food was not even touched. The second tent in the background was also damaged beyond repair.
The bear that wrought this damage was seen near camp a few days later. It was quite a small black bear. There were sleeping bags in this tent, but no contents were disturbed, a testament to the simple curiosity of the bear at this time. An encounter with a foraging bear would have seen the tents and any contents strewn about the forest.
At one point during the excavation the PRPRC was visited by a group that was excavating dinosaurs near Grande Prairie. The team was led by Dr. Phi Currie (University of Alberta).
A long bone (left radius) of a hadrosaur found near the edge of the pit fractured by exposure and slumping of the years.
The left radius completely exposed (the proximal end to the right is indicated by a small metal pick)
The radius is pedastaled and in a half jacket and ready to flip. The large area to the left of the radius turned out to be a section of articulated tail vertebrate, though at the time of the photo this was not known for certain. Both the radius and this section of the tail were at the edge of the hillside which was slumping. This area had to be excavated as they would not have survived another year in the field. This was the main reason why the pit had to be expanded, so that the bones in this area could be found, mapped, and removed before a catastrophic slump occurred.
The ulna jacket on the way out. All specimens excavated had to be removed this way. At least this jacket was much lighter than the femur from the previous year.
The radius after it has been prepared by PRPRC technicians.
Another juvenile tyrannosaur tooth found in the pit. By this year it was suspected that the number of shed tyrannosaur teeth was a bit out of the ordinary compared with other digs.
A series of articulated vertebrae with long neural spines. This was the first indication that the excavation site contained at least one partially articulated hadrosaur. If the palaeontologists had been less ambitious with the overburden removal this season, it may have been another year or more before this was encountered. The same day the palaeontologists encountered some of the bones of the hips in articulation with this series of vertebrae. The shape of the hip bones indicated that this specimen was allied with the crested hadrosaurs (lambeosaurines) instead of the flat-topped hadrosaurs (hadrosaurines).
Palaeontologist Lisa Buckley and technician Tyler Shaw jacketing the exposed hips (bottom of figure) and tail (top right) of the dinosaur prior to burying the site for the year. The distal part of the articulated tail is separated from the rest of the tail by a slump fault. This small section of the tail was removed and given a full jacket, but was far too heavy to carry out at the end of this season.