The Final Push

The penultimate day of the excavations finally arrived, and it was a race to the finish. We started the day shortly after dawn, in order to maximize the daylight (it’s winter right now in Angola, so the sun sets around 6pm). Luckily, Carla, the wonderful helper who makes our meals, sent us off with a thermos full of hot Angolan coffee. After a quick cup on site to kick-start our work, the day continued to fly by in a flurry of stone-carving to further isolate the blocks full of mosasaur bones, followed by round after round of wrapping the blocks in protective paper and plaster jackets for transport.

Finding the raw materials that are needed for these kinds of tasks, when in remote places in foreign countries, is sometimes quite a challenge, and you never quite know if the quality of what you have purchased is actually up to the task at hand. It turned out that the plaster we had purchased cured slowly and was not very strong. So today started out with a bit of experimentation, mixing the plaster with Portland cement to find the ideal consistency and hardness needed to keep the bone blocks intact. Eventually a recipe was decided, and the fossils were all safely enveloped on one side, with burlap strips dipped into the mix and wrapped around the exterior of each block. The larger blocks also had lumber incorporated in the jackets for additional strength. Once the plaster mix has dried fully overnight, we will flip the blocks and wrap the other sides tomorrow morning.

We also had quite an amazing surprise toward the end of the day, when a seemingly-small and inconspicuous bone remnant, partially dug out of an outcrop yesterday, turned put to be an absolutely enormous pterosaur wing element! It just goes to show how absolutely amazing this locality is, and also the importance of never underestimating the hint of a fossil weathering out at Bentiaba!!

Partial wing of a huge pterosaur. Copyright Projecto PaleoAngola.

Trenching the mosasaur (Post for July 10&11)

We have been working in the mosasaur quarry to expose bone and see how they can be separated into manageable sized jackets for removal. Once that was done we began cutting  trenches between the blocks encasing the bones. We also needed to dig pretty deep in front of and around the blocks to allow undercutting, and also removed rock from the hillside to create more space for the excavators. The skull block is quite large and the amount of bone it contains is promising, but we will need to wait until it is prepared in the labs before we know with certainty how much of it is preserved.   

Working in the Globidens quarry. Copyright Projecto PaleoAngola.

The remainder of the group, prospected and also measured the rock section to place specimens in the stratigraphic column.  After coming back to camp in the evening, the team discussed objectives for the last few days working in Bentiaba. Only three more days are left for fieldwork. The time here has passed quickly!

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.

More Globidens excavation and the K-Pg boundary (Post for July 7th & 8th)

On Sunday and Monday, the team was divided into two groups: one excavating the mosasaur quarry, and a second prospecting Paleogene outcrops near a potential K-Pg boundary. The team at the mosasaur site worked on removing rock above the bone layer. Careful exposure of bone is needed in order to know where blocks can be separated and removed from the bone layer. Small blocks are preferred, as these are lighter, but in some areas the bones are dense, and will require large jackets. The skull section is one of those areas that will require a larger block!
Continued work on the dig revealed the right lower jaw and a possible maxilla that includes those mushroom-shaped teeth that are diagnostic of Globidens. Our goal in the days ahead is to locate all the bones in the quarry, make sure everything is mapped, then begins to isolate and remove blocks of bone and rock in plaster and burlap jackets.

The K-Pg site continues to become more promising, as a dense layer of squid-like animals called nautiloids was discovered above the upper-most layer of the Cretaceous represented at Bentiaba. These cephalopods may be a taxon represented only in the age after the end of the Mesozoic. In addition to the nautiloids, some vertebrate remains were also discovered, another very exciting development. Continued work at both the K-Pg site and the mosasaur site will add significantly to the amazing geology and paleontological heritage of Angola!

Breaking out the power tools ( Post for July 6th).

The morning was cool and refreshing as our team, now six in total, sat for breakfast and reviewed the day’s objectives. We decided we would focus efforts on excavating the Globidens fossil.

We headed to the site prepared to move a lot of rock. We would use power tools to remove a wall of rock behind the mosasaur blocks to make room to work, and also to remove more rock overlying the bones. Most of the time, preparing fossils for study is a meticulous process and sediments are removed from bones in the lab with small, specialized hand tools such as airscribes (miniature pneumatic hammers) or dental tools. But the field is a different story! Since our objective is to safely remove fossils on a short timeline, we sometimes rely on electric powered jackhammers to remove a large volume of the overlying rocks, and today was just that day. Everyone took a turn with the rotary hammer bringing down higher ledges of rock in order to work at the layer that contained the mosasaur bones. Once we got close to the bones, we switched to hammers and chisels and other hand tools to approach bones more cautiously. And so, the site starts to reveal its secrets, bone by bone. As we worked to isolate bones that we were already aware of, new bones started to be exposed. One great discovery was a series of vertebrae from the end of the tail on one side of the accumulation, and vertebrae from the base of the tail on the other side. There’s still a lot of rock to remove, so we’re hoping the middle part of the tail is represented as well!!!

Of course, you need to stretch your legs periodically, so members would occasionally take short prospecting walks, locating more mosasaur, plesiosaur, and turtle fossils. Besides, the richly fossiliferous Cretaceous beds, there are also younger sediments, possibly Pleistocene in age. Those are the rocks that one of our team found mammal teeth and bones and fragments of ostrich shells. A great find indeed!!!

Tomorrow, we will continue work on the Globidens dig and of course, prospecting Bentiaba for more amazing finds.

Opening the quarry!!

Opening a fossil quarry is always an exciting moment, but especially today, because one of the mosasaurs that was partially excavated in 2017 is going to finally be collected this season! The mosasaur from this quarry, identified as the species Globidens phosphatius, was a large marine lizard that preyed on massive bivalves, with large shell-crushing teeth shaped like mushrooms. The team ran out of time to complete the excavation in 2017, so the specimen was capped with plaster jackets, and buried to camouflage it’s location.
After breakfast (with more delicious Angolan coffee), two of our team members, Alexandra and Miguel, were dropped-off at the mosasaur site to begin removing the overburden from the blocks containing the bones. The other team members were meeting the governor in Namibe. We had relocated the exact position of the fossil the day before with gps and photographs, so the work was started with shoveling and brushing away the sediment overlying the mosasaur blocks. Although this kind of work may seem tedious, it is actually exciting, since bones can be exposed at any moment. Working diligently, the blocks containing the mosasaur bones were slowly uncovered, along with isolated plesiosaur and mosasaur teeth! When digging in Bentiaba, there is always more to find…!!!
In addition to previously uncovered bones, new mosasaur bones were discovered alongside the plastered blocks. The sediment surrounding them was chipped away revealing they were limb elements. In the late afternoon, the rest of the team returned to Bentiaba and arrived at the site with another new team member, Geoveth! He grew up in Angola and studied geologic engineering at the Universidad de Moa in the Republic of Cuba. Just a few minutes walking around and showing him the bones and teeth spilling out of the rock outcrops was all that was needed for him to appreciate the amazing richness of Bentiaba. 
Coming back into camp, after a day’s work was welcomed by warm showers, and for dinner: roasted gazelle! Tomorrow we start by removing overburden and expanding the quarry into the hillside.

Finally on the outcrops!

Today was a great day.  A good nights sleep, good Angolan coffee at breakfast, getting our supplies organized, and then off to the outcrops of Bentiaba.  We have two new crew members with us this year.  They are grad students at the New University of Lisbon, working on plesiosaur and pterosaur material collected at Bentiaba.  To orient them, we started the day with an overview of the geological section and visiting all the major localities in the area.  The famous Bench 19 locality, with its incredible fossil wealth, represents only about 240 thousand years, set in the Lower Maastrichtian, or about 72 million years ago.  However,  the Mesozoic section in this area ranges from about 130 million years ago to about 66 million years ago, and preserves the remarkable record of the separation of Africa and South America and the early opening of the South Atlantic, so there was a lot of ground to cover.  

Lower Cretaceous sediments north of Bentiaba.

At one of the stops, our plesiosaur worker, Miguel Marx found a mosasaur skull, weathering out in the Upper Campanian part of the section, between Bench 2&3, in our published stratigraphic scheme (Strganac et al., 2014).  This is one of the oldest mosasaurs from this area and the first with skull material preserved. Vertebrates are generally more rare in this part of the section, so this is truly a significant find.  Miguel and fellow grad student Alexandra Fernandes, determined its stratigraphic position and did some preliminary triage of the specimen, which will be excavated at a later date. We ended the day with a visit to the Bench 19 locality, relocating the Globidens phosphaticus skeleton we found in 2017.  We will start the excavation of that specimen tomorrow morning.

Grad students Miguel Marx and Alexandra Fernandes triage a mosasaur skull, low in the section at Bentiaba.

Strganac, C., Salminen, J., Jacobs, L.L., Polcyn, M.J., Ferguson, K.M., Mateus, O., Schulp, A.S., Morais, M.L., da Silva Tavares, T. and Gonçalves, A.O., 2014. Carbon isotope stratigraphy, magnetostratigraphy, and 40Ar/39Ar age of the Cretaceous South Atlantic coast, Namibe Basin, Angola. Journal of African Earth Sciences99, pp.452-462.location

The road to Bentiaba.

How can we possibly describe the whirlwind that is the Lubango shopping experience? While transiting from store to store, you are constantly treated to the vibrancy of Lubango. From the vivid colors of the people’s clothing, to the Portuguese being shouted across busy streets, to the chaotic flow of the traffic.

  The shopping process itself is not straightforward, although the friendly locals are always willing to lend a hand or give a useful tip.  We were pleasantly surprised to find plaster and ethanol available from certain hardware stores, but then went on quite a wild goose chase for acetone (a key ingredient for our field consolidant mixture).  After scouring various suppliers and running down many leads with no luck, we eventually emerged victorious from…a beauty supply store!!  We may have decimated their inventory, but we emerged with many tiny bottles of nail polish remover.  With everything packed in  the Land Cruiser, and after a quick stop to pick up sandwiches, we set off for Bentiaba.

Serra da Leba- image from

Our journey to Bentiaba was initiated with a spectacular drive from Lubango to the edge of the plateau, before dropping into a meandering series of hairpin turns descending from the plateau, Serra da Leba. What a spectacular vista.  After the initial decent, Baobab trees could be seen clustered together, some still bearing fruit, reminding us “we are definitely in Africa”.  Continuing down, you are driving through a surreal landscape of beautiful eroded granite giving way to the gently rolling coastal desert.
At the end of our previous field season, we had left much of our field gear with friends in the coastal town of Moçâmedes which was our next stop, late in the afternoon.  A quick inventory of the supplies  verified we had everything we needed for the field.  So after loading the car, we set off for our final stop of the day;  our base camp at Bentiaba.  When we arrived, late in the evening, dinner was ready and the tents were set!  All thanks to one of our long-time outfitters that has supported our stays at Bentiaba since 2006.  A delicious meal of bitoque (Portuguese-style steak with egg) rejuvenated our energy after a long day.  Tomorrow, the field!  Tomorrow…the fossils!

On the ground in Angola

Our plane landed early this morning in Luanda, the capital of Angola, as the sun was rising. As with all field seasons, there are a lot of tasks that need to be accomplished; from reuniting with our Angolan colleagues to managing logistics and field supplies, and of course spreading the word about Projecto PaleoAngola. One of the most fun and rewarding things today was the spontaneous mini-conference with students in the Geology Museum of Agostinho Neto University. We had stopped in to show some of the new additions to our field crew the skeletal reconstruction of Angolatitan, and other fossils that have previously been returned. There happened to be a group of undergraduate students receiving a lecture on mineralogy there, but our host, and department head of geology, Olimpio Gonçalves, approved us showing the students some of graphics and videos from the Smithsonian exhibit “Sea Monster Unearthed: Life in Angola’s Ancient Seas”. It was a huge hit! We also showed a prototype augmented reality phone application that allows them to visualize what these ancient animals looked like and how they moved. The students were incredibly enthusiastic to hear about the exhibit and to learn about the international visibility the fossil heritage of Angola was receiving.

Projecto PaleoAngola team members interacting with undergrad students at the Geology Museum of Agostinho Neto University.

In the afternoon part of the team moved to southern Angolan to stage equipment and supplies and the other to manage meetings and some logistics in Luanda. By tomorrow night, the southern group will be at our base camp, just a few kilometers from the wonderful outcrops at Bentiaba, where we will begin excavations of previously discovered fossils and of course find many many more new ones!!!!.

Field Season 2019 Begins!!

Flying to Angola tonight.  Looking forward to getting back to the outcrops and continuing our work at Bentiaba.  There are a number of important specimens to be excavated this year, (and many more to find), as well as refining the stratigraphy of the rocks above the famous Bench 19 locality which produced so many of the spectacular specimens featured in the Sea Monsters Unearthed exhibit at the Smithsonian Natural History Museum.  In 2017 we collected part of a gigantic Prognathodon well above Bench 19, in sediments we believe to be Late Maastrichtian in age, so this year we will test that idea and also continue up-section, in search of the Cretaceous-Paleogene boundary.