Tuesday, August 7, 2012

Brief Field Update!

Hello from the field! To be accurate, I am not posting directly from the field site as we do not have internet access. I have mixed feelings about that. The downside is that we tend to miss out on current events, such as all the Olympic coverage. The benefit is that most people we deal with know about our annual summer absence and tend to keep the last minute "I need X by tomorrow...I've known about this for a month but am just letting you know now" demands (e.g. museum statistics, financials, forms to sign, etc.) to a minimum.

I digress. I want to post an update on what we've been up to since the first week of July. We resumed the BC hadrosaur excavation on July 5th. Here's a bit of background. Since 2004 we have been prospecting the approximately 73 million year old outcrops of northeast British Columbia for dinosaur material. We knew from the finds near the Grande Prairie area that British Columbia had the potential to produce ceratopsians, hadrosaurs, tyrannosaurs, ankylosaurs, and other animals similar to the charismatic creatures discovered in the Upper Cretaceous deposits of Alberta. The first report of bone material was made by a family from the region. Unfortunately the few remains were encased in very coarse grained sandstone in a gravel pit. Why was this unfortunate? First, when paleontologists and geologists talk about grains, they are referring to the size of the particles that make up the rock in which the dinosaur bones are encased. Most of the rock layers in this region are deposited by water (lakes, streams, rivers, deltas, etc.) So, the larger the individual grains (or, the coarser the grains), the faster the water had to be to move them and deposit them. Most of the bones we find in coarse grained rock tend to be individual pieces rather than complete skeletons, and those pieces tend to be broken. The report was enough to tell us that all we needed to do was look (and look, and look, and look some more) and eventually we would encounter a site that contained a large amount of bone.

In 2007 Rich, our colleague Dr. Federico Fanti and I came across a hillside that contained a great deal of eroded bone that stretched over 10 meters. The bone was of a hadrosaur, but what kind of hadrosaur remained to be seen. This was enough for us to return to the site in 2008 and conduct a test pit. We discovered we had at least part of a disarticulated skeleton. In 2009 we discovered that a large portion of the skeleton was mostly articulated. In 2010 we discovered the pesky skeleton was missing the neck and head, and that the pectoral limbs had been pulled off prior to burial. This was also the year we found  several tyrannosaur teeth associated with the skeleton. We uncovered a large portion of the pelvic girdle, and the shape of the bones indicates that we are dealing with a crested hadrosaur. In 2011 we had planned to remove the skeleton, but the Great Weather Gods had plans of their own and rained for four weeks out of our five week field season.

This brings us to 2012. We have had a successful excavating season to date. The process of removing the skeleton is well underway. The protective plaster jacket that encases the exposed parts of the body has been expanded and reinforced. We have also started digging under the jacket and applying plaster to the underside of the skeleton. This will ensure that, when we move the jacket out of the wilderness and into the museum, the insides of the jacket won't fall out when we eventually flip the whole jacket over during the process of separating it from the hillside. We are about a week away from being ready to flip the jacket. On that day I am sure I will be so nervous I'll add to the already numerous stark-raving-white hairs on my head. Maybe this is the year I finally get a pure white streak in my hair.

We've also successfully removed the tibia, a mostly complete rib, and several smaller pieces of partial ribs. We haven't found many new skeletal elements this summer because are concentrating on removing the main part of the skeleton. However, while I was digging around the rib, I uncovered a new limb bone (likely a humerus) with a new rib laying across it. Once I sort through the many images I've taken, I'll post some pictures.

That is all the news I have for now. The next time I'm in town will likely be when the skeleton is removed.

Off to wash field laundry....

SAS 

No comments:

Post a Comment