Sunday, July 29, 2012

Trip to Chile, pt. 4

After some fieldwork (see previous post) it was time to do some preparation of the material we collected. We did some preliminary prep work at the Cabañas, but most of it was done over at the Museo Paleontológico de Caldera. There was also a lot of additional material collected over past expeditions, and we wanted to take good publication quality photos, specially of the material from Cerro Ballena.
Members of the expedition get some initial prep work done on some of the material we collected over the past few days.

More prep work, this time at Museo Paleontológico de Caldera. Cony and Carolina talk about fossil billfishes, while Ana and David are busy preparing pinniped material.

 Luckily, before we headed back to Santiago, we had time for one more trip to the field. This time we went to some Neogene badlands, that have yielded remains of sharks, cetaceans, pinnipeds and penguins. Our time was limited, but was still fun to be out in the field one last time.

Neogene badlands of the Atacama, even with less plant life than the ones I visited earlier in the year in Baja California Sur. In stark contrast with what I usually deal with in Puerto Rico.

One of several shark teeth we found. This one hints at the age of the deposit.

One last view of the Atacama, as the sun settled and we headed back to Caldera and to Santiago the next morning.

The trip is not over, more to come, so stay tuned!

Go read previous installments of this series: Part 1, Part 2, and Part 3.

Also, go see Nick's here, here, here and here.

Wednesday, July 25, 2012

Trip to Chile, pt. 3

Like I mentioned in the previous post, we returned to the Cerro Ballena site. There we looked for fossils that might still be exposed in the outcrop. We didn't find much, but we did found some interesting stuff.
David, Nick and Roberto, dig a baleen whale vertebra in Cerro Ballena. Several, nearly complete skeletons were previously collected at this locality and are waiting to be prepared at the Museo Paleontológico de Caldera.

An interesting find was the remains of a billfish. Here David, Cony and Roberto collect the remains, while Nick and Carolina were taking notes on the locality and horizon. Missing from the picture are Ana and Mario, who were in another part collecting remains of the aquatic sloth, Thalassocnus.

We also visited some other localities, including one that yielded remains of Pelagornis chilensis amongst other interesting stuff!
Ana, David and I as we walk to another sites where remains of other marine vertebrates have been collected.

Unfortunately, poachers also know of these sites and go looking for shark teeth and other fossils to sell, which is illegal! So in many places we knew the location of bone beds because of the shattered remains of material thought as uninteresting to poachers.
The example above show some penguin bones that were left behind by poachers. These was actually my first encounter with penguin bones in the field!

More posts to come, so stay tuned!!
Also, go see parts 1 and 2 of this series!

Tuesday, July 24, 2012

Trip to Chile, pt. 2

Things have been pretty busy over the past several days. Between work at the museum in Caldera, fielwork and spending time working on manuscripts I haven't really been able to post as much as I wanted to. Anyways, like I mentioned on the previous post, we've been spending some time studying fossil material at the museum during the day, while in the afternoon we work on manuscripts, abstracts and the like.
Afternoon in the cabaña after a long day of data collecting. Mario (left) prepares the fire, while Nick, Roberto and Carolina work on manuscripts.

One of the benefits of staying in a coastal town is the fresh seafood, which we buy at the market and then cook it ourselves. Just because we are on the field it doesn't mean we have to eat poorly!
Fresh albacore tuna fillet and shrimp and veggie skewers. It was delicious!!

We've also been out in the field. We revisited the Cerro Ballena site (above), as well as some other localities. More on this on the next post, so stay tuned!

You can see the first part of this series here.

Friday, July 20, 2012

Trip to Chile, pt. 1

So a few days ago,  Nick and I arrived to Chile, where we'll be for the next couple of weeks. The purpose of this trip, is to look at collections and visits Cerro Ballena and some other localities in the Atacama region. Some of our colleagues were waiting for us in Santiago, David, Carolina, Roberto and Anita who live there, and Mario Cozzuol who had arrived earlier in the week from Brazil. That afternoon, we headed out to Caldera, in the northern part of the country.
We are staying in some lovely cabañas, with a nice view to the Bahía de Caldera and the city.
The view at night from the cabañas.

At the cabañas, talking with the owner.

The next morning we visited the Museo Paleontológico de Caldera, where we met with another of our colleagues, Mario Suarez. At the museo we spent the day looking at the material collected from Cerro Ballena and nearby localities. The fossils from this site includes a wealth of marine mammals, mostly whales and dolphins, but also, aquatic sloths (more on that later)!! 

Here's a view of some of the material collected from Cerro Ballena, nearly each one of those jackets have remains of baleen whales!!

So, stay tune for more upcoming entries from this trip. Also, go over to the Pyenson Lab where there will be posts about this trip as well.

Friday, July 13, 2012

A short trip to Panama

A couple of Friday’s, no, about a year, ago one of my advisors, Nick Pyenson (NMNH), and I were on a flight on our way to Panama. The main purpose of this trip (only a weekend long) was to collect a nearly complete skull of an odontocete, (toothed whales), which we originally thought was a squalodontid (but it isn't, more on that later). We learned of the fossil through Aaron O’Dea of the STRI/CTPA, as one of his students, Dioselina Vigil had spotted the skull while prospecting along the shores of a town called Piña, on the Caribbean coast of the country. The rocks exposed in that area, best seen at low tide (see picture below), are part of the Chagres Formation (Fm.), a sandstone unit that has been dated to between 8-6 million years ago (Ma) (Late Miocene) (Collins et al., 1996).
View of the Caribbean Sea, near the town of Piña, Panama. The rocks seen in the lower half of the picture are part of the Chagres Formation.
By Saturday morning we were in the outcrop, together with Aaron, Dioselina and her brother, as well as other colleagues from STRI and a couple of visitors from Temple U. Our main purpose was to dig out the squalodontid skull as well as do some prospecting. In order to collect the skull we had to make the most of the low tide, which was the only moment that it would be exposed. As we began digging around the fossil, we realized that it was going to take longer than we had expected. Therefore we divided the group, some went prospecting while four of us stayed behind digging out the skull. After a while we realized that the fossil consisted of not only the skull, but that also the mandibles were there. In all, it took us about four hours, with the tide creeping upon us by the last half hour (see pictures below), to collect the fossil. Needless to say we successfully collected the squalodontid skull, and the prospecting team made some interesting finds as well, including additional marine mammal remains (both, whales and seacows!).
Above: Nick, Dioselina and I finish one of the small jackets. This whole area had been exposed earlier that day, this picture was taken within the last hour of low tide. As you can see the sea is creeping around us.
Above: Nick, next to the jackets containing the odontocete remains. Notice in the background that the area where we collected the fossil (between the logs) is now completely covered by water.
The skull is actually not the first marine mammal fossil known from Panama; it is, however the most complete/diagnostic so far. Back in 2010, Mark Uhen and colleagues reported marine mammal remains from three other rock units in Panama: the Tobabe Fm. (7-5 Ma), Gatun Fm. (12-8 Ma), and the Culebra Fm. (23-20 Ma). From the Tobabe they described a thoracic vertebra of a balaenopteroid (the group that includes rorquals and gray whales), from the Gatun odontocete ribs, and from the Culebra a dugongid (seacow: dugong) tail vertebra (Uhen et al., 2010).
Other interesting fossil vertebrates that have been collected from the Chagres Fm., include a fossil marlin, Makaira panamensis which was described by H. L. Fierstine in 1978. This is of particular interest as during out expedition, we also found marlin remains, including one that seems to be complete, head to tail (see picture below)!
Me and the fossil marlin. The tail is the fan or boomerang-like structure seen in the foreground (near the bottom of the picture) I am in the background pointing to the rostrum/beak. This is probably the most exciting fossil fish I’ll ever found!
These finds, as well as the chances finding even more, mean just one thing, we will have to go back to Panama!
You can find out more about this trip by following these links:
And at Smithsonian Ocean Portal where you can find the following:
-Paleobiology Blog: Part 1, Part 2, Part 3
Collins, L. S., A. G. Coates, W. A. Berggren, M.-P. Aubry & J. Zhang. 1996. The late Miocene Panama isthmian strait. Geology 24:687-690.
Fierstine, H. L. 1978. A new marlin, Makaira panamensis, from the Late Miocene of Panama. Copeia 1978:1-11.
Uhen, M. D., A. G. Coates, C. A. Jaramillo, C. Montes, C. Pimiento, A. Rincon, N. Strong & J. Velez-Juarbe. 2010. Marine mammals from the Miocene of Panama. Journal of South American Earth Sciences 30:167-175.