Earth Sciences in Angola

A graduate student and a postdoctoral researcher in SMU’s Roy M. Huffington Department of Earth Sciences, along with Professor Louis L. Jacobs, are conducting research in Angola in southern Africa during summer 2012. They are members of an international scientific program called the PaleoAngola Project, which seeks to discover and study Angola’s vertebrate paleontology and learn about the environment in which prehistoric creatures lived. Readers also can follow their work at paleoangola.org/

Our last day in the field

An update from Scott and Ricardo:

Last time we were at Malembo Point, Dr. Jacobs befriended a sea turtle that would surface occasionally to check on our work. As we were hiking down to the locality today for a last round of fossil collecting, we met a group of fishermen. When we asked to see their catch, Dr. Jacobs was disappointed to see that they had caught a turtle. After a few hours on the beach, though, we saw a little turtle head poking out above the waves, so maybe “our” turtle is still alive and swimming happily through the ocean.

We are all pretty tired at this point, but we’ve managed to collect good stratigraphic data and some important fossils. We’ll fly back to Luanda tomorrow and spend the next few days arranging to have our samples shipped back to Dallas, so this will be the final entry of the field blog.

We’re very grateful for the generous funding provided by the Institute for the Study of Earth and Man at SMU, the Vida Foundation, and Esso. Without the support of these sponsors, our work in Cabinda would not have been possible.

We’ve enjoyed sharing our Angolan adventures with you and hope you’ve enjoyed following our progress. Until next time.

Dr. Jacobs searching for fossils at the Malembo Point locality.

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A run-in with modern-day mammals

An update from Scott and Ricardo:

One of the baby rats we removed from behind the glovebox

As we were driving into Cabinda City this morning to make arrangements for our flight back to Luanda on Wednesday, Ricardo noticed that the ownership and insurance documents for the rental truck were missing from the glovebox. We immediately returned to search our rooms, but we soon discovered that our friendly local rodents had built a nest behind the glovebox on top of the AC filter.

Scott donned latex gloves and pulled a mess of shredded paper, plant debris, bones and plastic bags from inside the dashboard, as well as three baby mice. Luckily, the rental documents survived relatively intact. This explains why the car smelled less than fresh when we turned on the AC. Now we drive with the windows down instead.

We finally finished measuring the stratigraphy to the north of Malembo Point, and we managed to correlate the rocks we measured today with those at the more northern localities. The stratigraphic measurements are more or less done at this point, and we plan to spend our last day in the field tomorrow collecting more fossils from the Malembo locality in the hopes of finding more mammal material.

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Filling in the blanks

An update from Scott and Ricardo:

Ricardo buying bananas at a roadside stand to replace the provisions eaten by the rats.

We started out this morning with an unexpected surprise. Last night we were so tired when we returned to our rooms at Futila Beach that we forgot to remove the day’s lunch leftovers from the truck. This morning, when we loaded our gear into the vehicle, we found that the food had been discovered by some industrious rodents that had plowed through several bananas and empty sardine tins. To repay our generosity, the rats left us little brown “presents” all over the seats and floorboards.

After cleaning out the truck, we drove to Malembo and hiked down to the beach. Malembo Point is the fossil locality where Dartevelle and others collected several ancient mammal teeth, and where we have also found important fossils in previous years. The stratigraphic sequence just to the north of this area is impossible to measure since the rock exposures are covered by jungle.

Ideally, the rock record would provide us an entire ‘book’ so we could easily read the Earth’s geologic history. Unfortunately, this book is always missing a few pages, so we have to read what we can and try to interpolate the missing parts. Today, we measured the rocks between Malembo Point and the mouth of the Sapho River, filling in a little more missing information about Cabinda’s geologic evolution.

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Moving on to Malembo

An update from Scott and Ricardo:

Ricardo cutting sugar cane.

We finally completed as much of the stratigraphic section as is possible working south from Lândana. We measured approximately 32 meters of section and collected over 150 fossils (mostly shark and ray teeth). That works out to an average sampling density of around one tooth every 20 cm!

Now we will switch our focus to the outcrops near Malembo and attempt to correlate those rocks with what we’ve measured at Lândana.

After we finished at Lândana, we drove south to try to locate a way down to another of the localities that Dr. Jacobs visited a few years ago. With the help of a local villager, Ricardo and Dr. Jacobs hiked down to the beach. The villager, named João, was a skilled contractor, who was born and raised in the 4th February neighborhood. He told us that in Cabinda his friends and family mostly work on hunting, fishing and farming.

Scott stayed behind to catalog fossils and rock samples and work on his field notes. On the way down to the beach, Ricardo and Dr. Jacobs ran into some ants, but they managed to escape with just a few small bites. If there’s one thing Angola has in abundance (aside from oil and diamonds), it’s ants.

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Seeking clues about our earliest ancestors

An update from Scott and Ricardo:

Ricardo braving the cliffs at high tide to access the beach near Malembo.

Not all days are great days, and today was rather difficult. We decided to revisit one of the fossil localities that we first explored about two years ago. We wanted to link the rocks we measured yesterday to those at this locality by working northward back toward Lândana, but the steep cliffs and monstrous rock falls prevented us from doing that.

However, we were still able to collect more shark teeth for isotopic analysis, and we measured the strata exposed at the locality. It may be an idiosyncrasy of working in the tropics, but getting to the beach can be quite an arduous task. The jungle grows fast, and it’s often difficult for local villagers to maintain the paths and prevent them from becoming impassable. We spend a good deal of time just trying to find a way down the cliffs to the outcrops on the beach.

The 15 km stretch of outcrop we need to measure and sample may provide invaluable clues about the evolution of early human-like primates around 50 million years ago. Previous field work unearthed the tooth of an anthropoid primate near the town of Malembo. Although landslides and coastal erosion have made this site difficult to reach, it may yield more material with the potential to illuminate the deep history of our earliest human ancestors. This is just another reason Cabinda is such a unique and exciting place to work!

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No mammals, but a bird fossil

An update from Scott and Ricardo:

We returned to Lândana again today. We are carefully working our way south toward Malembo Point. In order to determine how these two localities are related to each other, it’s imperative that we link them stratigraphically by tracing the rock layers from one to the other.

Dr. Jacobs found the upper arm bone of a very large crocodile, which was artfully removed from the encasing rock by Ricardo. We continued to collect numerous shark and ray teeth from throughout the stratigraphy until the rising tide forced us to quit work and move to a different site before we found ourselves stranded.

We located a dirt road that leads to the beach near the mouth of the Sapho River, several kilometers south of Malembo. Earlier work in this area by Belgian paleontologists indicated the presence of marine mammal bones in conglomerates cropping out in this area.

Although we collected teeth belonging to sharks, rays, and crocodiles, we weren’t able to find any mammal fossils. Ricardo hiked northward down the beach until he reached Malembo Point and found a fossil bird bone. Since bird bones are hollow and often small, they are relatively fragile and have a low preservation potential, so this is a major discovery!

Scott preparing to measure the stratigraphic section at Landana.

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Found: a well-preserved turtle skull

An update from Scott and Ricardo:

This morning we got up at 6:30. Low tide was at 10:25, so we wanted to arrive in Lândana as early as possible in order to maximize our time on the outcrop before the tides rose again in the afternoon.

One of the fossils Dr. Jacobs uncovered yesterday turned out to be an exceptionally well-preserved turtle skull! This material may belong to the genus Bantuchelys, specimens of which were collected at Lândana, described, and named by the Belgian paleontologist Dartevelle in the 1930s. However, Dartevelle’s Bantuchelys material consists of only the shell, which is currently housed in the Royal Museum for Central Africa in Tervuren, Belgium, just outside of Brussels. Our new find is the first turtle skull known from the Cenozoic of Western Africa.

Scott Myers has been describing the stratigraphic section in detail, and Ricardo Araújo has been collecting shark teeth from as many of the stratigraphic layers as possible. Once we get back to Dallas, we will measure the oxygen isotope composition of the tooth enamel, which we can use to estimate marine paleotemperatures.

This is just the beginning; soon we will be able to unveil the paleoecological mysteries of one of the classic examples of early Cenozoic African coastal ecosystems here in Cabinda.

Ricardo excavating turtle skull at Landana.

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First day in the field in Cabinda

An update from Scott and Ricardo:

After a brief stay in Luanda to procure the necessary travel documents, today was our first day in the field here in the northern Angolan enclave of Cabinda, which has some of the most exceptional fossil localities in lowland equatorial Africa.

We drove north to the town of Lândana, where we stopped to measure part of the stratigraphic section and collect fossils that were weathering out of the outcrop, including turtle, crocodile, and fish bones. We spent the rest of the afternoon looking for a way to access the outcrops farther south at Malembo Point.

Along the southern coast, the luxurious Angolan forest emerges, and our path to the beaches at Malembo Point was cut short by a thicket of lianas, bamboo and bushes. The cliffs in this area are very steep, and it appears that it may be a tough hike to get in and out, although the payoff will undoubtedly be worth the effort!

We tried once again to reach the beach using an alternate route suggested by a local hunter, but most of the rocks in this area are heavily weathered and converted to laterite, a type of soil that is abundant in equatorial and tropical regions, so we will need to look elsewhere near Malembo for “good” unaltered outcrop.

Tomorrow we will return to Lândana to finish our work there. One of our goals here is to describe the rocks in detail so that we can determine the type of environments in which they were deposited and provide important contextual information for the fossils.

Scott taking notes at Landana locality.

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Uncovering a mosasaur skull

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.

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Banana-dogs for lunch

Mike and Louis' field truck, AngolaAn update from Mike:

Just a quick update to kick off the field blog for this year. Louis and I arrived in Luanda on the 1st of June and with the help of many friends and colleagues here in Angola, we managed to get all of our required supplies, vehicle, and our travel documents in record time…a single day. That enabled us to leave Luanda on Saturday morning, and begin our journey to the marine cretaceous field localities in the south.

We spent Saturday night in Benguela, on the coast of Angola. Sunday morning we headed inland and drove up to the plateau, then south to Lubango. We are meeting with old friends and colleagues along the way and finalizing details of schedules and dealing with logistics issues. Great driving weather both days and the scenery is fantastic. Along the way we stopped under the shade of a tree for a lunch (banana-dogs and water – see recipe below). Tomorrow, we are heading for Namibe, and hopefully will be in the outcrops by Tuesday.

Banana-dogs for lunch, AngolaBANANA-DOGS RECIPE

Ingredients:

• A bunch of bananas – preferably a variety of banana that grows around Benguela, within a couple hours of being cut from the tree

• 2 Portuguese bread rolls (fresh this morning, liberated from the breakfast bar at the guest-house in Benguela)

Mike and Louis, AngolaPreparation:

Put a whole banana on half of a bread roll. Repeat 2 times, for each serving.

Serves two paleontologists. Best eaten from the hood of your field vehicle. Serve with bottled water, recent vintage preferred.

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