And the dig goes on (Post for July 9th)

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).

Left mandible of Globidens phosphaticus. Copyright Projecto PaleoAngola.

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.

Tail vertebrae of Globidens phosphaticus. Copyright Projecto PaleoAngola.

The second half of the team met a 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.

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 Biology22(1-3), pp.175-185.

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