PaleoAngola Field Camp at Bentiaba
It is the morning of the June 11. We have not had access to Internet so we have been unable to update the blog. Last night, wildlife biologist Pedro Vas Pintos drove the remaining part of the field crew, Octavio and Ricardo, from Lubango to our camp at Bentiaba. I was able to send a USB drive with this entry with him, so our colleague Anne Schulp in the Netherlands could update the blog for us.
Louis and I, along with the outfitters we hired in Namibe to supply logistics support (and most important, the cooks), arrived at Bentiaba late in the afternoon on June 5.
Our fantastic support crew... Lionel, Chilombo, and Cici
Breakfast with Pedro Vas Pintos and family and the PaleoAngola field crew
After making camp, Louis had to return to Lubango to pick up another of our team members, Tyrone Rooney from the Michigan State University at Lansing. Tyrone is a geochemist specializing in igneous rocks. He has joined us to examine the geochemical characteristics of the abundant basalts in the region. The coast of Angola is a rifted margin, and Tyrone studies the igneous rocks of rift to deduce what happened during continental breakup.
Highlights of the week
On June 6 I left camp early and hit the outcrops to do some prospecting and walk off nearly a week of sitting in airplanes and cars. I decided to prospect higher in the section, in rocks that are somewhat younger than the beds we have worked in previous years. The morning was very productive, to say the least. In a mere few hours I had found a string of semi articulated plesiosaur vertebrae, a relatively fragmentary mosasaur skull, an interesting fish, a turtle, and a huge mosasaur skull of the genus Prognathodon! After a lunch break, I began to uncover the Prognathodon skull, and although it was pretty badly weathered, it did preserve enough to warrant excavating and preparing for study.
Detail of an isolated tooth of the specimen.
June 7 I continued to work on the large Prognathodon skull. Much of the work at this stage is carefully removing enough rock to define the limits of the fossil to determine how it can be removed as safely and as compactly as possible. We try to avoid exposing more than we need to avoid damage to the fossil.
Working into the afternoon, I was able to define two relatively small blocks for removal. I will complete the remainder of the excavation later, when I have some help moving the generators into place to drive the power tools. At that point we will trench around the specimen.
By late afternoon I was ready to do a little more prospecting and found a very nice turtle carapace preserved intact in relatively hard sandstone. No skull or limbs are visible, but given the nice preservation of the portion that is showing, I am hopeful more will be there.
Since June 8 I have been primarily focused on excavating a large mosasaur specimen that I found the last day of the field season in July 2011. At the time I found the 2011 specimen, only the shattered remains of a single tooth and a short segment of a jaw were showing. We were getting ready to leave the field the next morning, so with limited time, Anne Schulp and I uncovered only enough to confirm that there were at least three jaws with teeth in place, and came away confident that we had a semiarticulated skull. It was also obvious, given the size of the teeth, that this was a huge animal.
Over the past few days I have been able to uncover most of the skull and now have a good idea of the limits of the block. This will be one of the largest single blocks we have taken out in Angola.
Excavation of 2011 specimen of Prognathodon in process. You can see the jaws converging at the bottom. From left – right dentary, left dentary, left maxilla, right maxilla. Isolated teeth in lower left.
Now that I have had a few days with the specimen, it is clear that this is another large Prognathodon, the same species as the skull I discovered a few days ago. We currently have a paper in press reporting the occurrence in Angola of Prognathodon saturator (a species previously know only from northern Europe). The specimen that we reported was a small fragment of jaw and a single badly preserved tooth. These new specimens will give us a much more complete view of the anatomy and relationships of this animal and will tell us for certain whether we have that species here in Angola.