The mosasaur site has continued to yield many new bones. The most exciting parts to be revealed so far include a well-preserved articulated left mandible, missing the posterior part due to erosion. You will notice the teeth in the image below are not in place but have fallen out of their sockets. That is because Globidens phosphaticus, unlike other mosasaurs, never cement their teeth to the dentary, but instead maintain flexible periodontal ligaments through life, as we reported in our 2010 paper on this taxon (Polcyn et al., 2010).
A beautiful series of vertebrae, that in life would have been right in front of the fluke and downturned part of the tail, lie articulated in life-position, and was very exciting to uncover. Many other tail vertebrae can be seen disarticulated. We still have a large section of bone bed to uncover, so hoping for more great discoveries to come.
Octávio and Louis paid a courtesy call on the local government administrators in Bentiaba and showed them the Sea Monsters power point. At every presentation, the urgency of protecting the fossil sites is emphasized.
Then they met up with our group of four students from the Universidade de Agostinho Neto in Luanda that have joined us for the remainder of the expedition. The students were given a quick tour of the geology in and around Bentiaba and were briefed on the objectives for this year’s field season. The second team also worked on measuring the stratigraphy and collected sediment samples.
The first stop was to see a plant: Welwitschia mirabilis, the iconic and defining plant of the Namibe Desert in Angola and Namibia. It grows nowhere else today, but fossil leaves have been found in the Early Cretaceous of Brazil from a time when Africa and South America were still connected and the South Atlantic Ocean had not formed.
After cleaning up the quarry and arriving back to camp, the team gave a presentation to our camp hosts and fellow researchers and students, covering the work Projecto PaleoAngola has done over the years, culminating with the Smithsonian exhibit. Everyone seemed to enjoy it and afterward, one of our hosts gratefully exclaimed that finally being able to understand the ancient history of this place was like “a light” being turned on for her. We couldn’t have asked for a more rewarding end to a hard workday.
Polcyn, M.J., Jacobs, L.L., Schulp, A.S. and Mateus, O., 2010. The North African mosasaur Globidens phosphaticus from the Maastrichtian of Angola. Historical Biology, 22(1-3), pp.175-185.