Trip to Chile, pt. 5

After Caldera we spent some days in Santiago. Among the things we did there, was writing manuscripts and visiting the collections at the Museo Nacional de Historia Natural. We spent a lot of time working on abstracts for an upcoming meeting of researchers of aquatic mammals to be held in Puerto Madryn, Argentina. Also, we took some time to relax and do some sightseeing.

Having a nice lunch at El Patio.

One of the many awesome examples of street art we saw in Santiago.

Santiago is at the foot of the Andes and on clear days you can see them.

An Araucaria (monkey-puzzle tree), evidence that I was indeed in the southern Hemisphere.

David, Nick and Carolina, ponder at the jaws of a sperm whale (Physeter macrocephalus), in exhibit at the Museo Nacional de Historia Natural.

Lovely sunset over the Andes.

This concludes our trip to Chile, we work hard and we had great company and good times! 

Next stop, Peru!!

Previous entries in this series:

Part 1, Part 2, Part 3 and Part 4.

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.

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!

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.

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.

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:

Pyenson Lab

And at Smithsonian Ocean Portal where you can find the following:

-Paleobiology Blog: Part 1, Part 2, Part 3

-Slideshow

-Time-lapsed vide of the excavation

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.

Marine Mammals in an Old Print

I acquired this old print a while back (see image below). Not sure which is the source or the date. But based on the illustrations, it seems quite old (based on the engraver's name, probably sometime in the early 1800's). The reason I got it was primarily for the marine mammals, but there are also other animals which are curiously depicted.

Feel free to write in the comments which kind of animal you see in it, and/or peculiar things you notice in about them. Enjoy!

Dispatches from the field: Baja California, Pt. 8

Today, we set out to pop the jacket that we made yesterday afternoon. While the humidity from the night before dried, some of us kept working on smaller or isolated bones. Others went to town to make phone calls and arrange accommodations for our stops on the way back to Ensenada the next day.

It was a lovely morning to dig bones, as well as for surfing (you can see a surfer to the right). Daryl and Ehecatl take care of some isolated elements while the jacket dries.

We started digging around the jacket with our picks and hammers to remove it. One of the locals, Cal, offered to help us with more advanced technology.

The jacket, popped and ready for capping. This and all the other fossils we collected will go to the Universidad Autónoma de Baja California Sur. Later this year, hopefully, we'll get some of the material on loan so we can start describing it and publishing on the interesting finds that resulted from this trip.

After one last look at the bay we headed out to begin our four day trip back, first to Ensenada, then to Los Angeles.

For past entries of this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Dispatches from the field: Baja California, Pt. 3

Dispatches from the field: Baja California, Pt. 3.5

Dispatches from the field: Baja California, Pt. 4

Dispatches from the field: Baja California, Pt. 5

Dispatches from the field: Baja California, Pt. 6

Dispatches from the field: Baja California, Pt. 7

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.

Dispatches from the field: Baja California, Pt. 7

So we continued more or less where we left the previous day. We set out to establish the limits of the bone concentration, getting it ready for jacketing.

This is the bone concentration that we jacketed latter that day. They're mostly sirenian ribs, but there's also a humerus (you can see it towards the center of the block).

Among the most interesting fossils that we found in the bone bed this day was this fragment of baleen whale mandible. More specifically it seems to be that of a herpetocetine, an extinct group of (somewhat small) baleen whales. 

Ehecatl, Gerardo and Daryl dig out smaller isolated bones from the bonebed while Fernando and Larry begin jacketing the block with the bones (seen above).

The view from where we were staying. If you click on the picture you can spot the jacket (towards the center left). Tomorrow we'll remove it and wrap things up.

For past entries of this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Dispatches from the field: Baja California, Pt. 3

Dispatches from the field: Baja California, Pt. 3.5

Dispatches from the field: Baja California, Pt. 4

Dispatches from the field: Baja California, Pt. 5

Dispatches from the field: Baja California, Pt. 6

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.

Dispatches from the field: Baja California, Pt. 6

After a day in La Purísima we were ready to keep digging at the bonebed we found several days ago.

Fernando (on the left) works on some cetacean bones, while Daryl (center) and Ehecatl (to the right of Daryl) remove sediment from around some sirenian bones. Larry (upper right) removes overburden.

As you can see in the image above, bones are sometimes jumbled together. Here's are two dugongid sirenian ribs and an atlas.

One of the most interesting finds of the day was this crocodylian cervical vertebra that I found. We started to find croc teeth around some of the sirenian bones. Then latter on this vertebra, some big kind of croc was lurking in Baja California during the early Miocene!

The field team (from left to right: Gerardo, Larry, Daryl, Fernando and Ehecatl) pose in front of a concentration of sirenian bones that we are preparing to jacket in the next couple of days. This so far, has been the most productive locality.

For past entries of this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Dispatches from the field: Baja California, Pt. 3

Dispatches from the field: Baja California, Pt. 3.5

Dispatches from the field: Baja California, Pt. 4

Dispatches from the field: Baja California, Pt. 5

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.

Dispatches from the field: Baja California, Pt. 5

This day we headed to La Purísima, to look at more early Miocene outcrops. Specifically we wanted to relocate the type locality of Dioplotherium allisoni, a large-tusked dugongine that is known by the type, a fragmentary mandible, and some referred specimens from California. We still know very little of the morphology of this animal and would like to find more of it.

On the way there, we stopped at a locality where the late Oligocene San Gregorio Fm. and the early Miocene Isidro Fm. are exposed. (above).

Sirenian ribs as well as a variety of fish teeth were quite common in the basal conglomerate (just above my rock pick) of the Isidro Fm. (above).

After our stop to look at the contact between the San Gregorio and Isidro formations we continued our way to La Purísima in search of the type locality of Dioplotherium allisoni. To our luck, Kilmer (1965) in his description of the species, provided a very detailed description of how to get the the locality, that plus our colleague from UABCS, Gerardo González, knew the way as he had been to the locality on a previous occasion.

The type locality of Dioplotherium allisoni in La Purísima (above). Something that Kilmer didn't mention was the the vast majority of the sirenian fossils were inaccessible as they occur nearly exclusively on the bottom of the bed that forms the ledge.

The bottom of the ledge (above). Click on the picture and you'll see some of the sirenian bones in the layer (mostly ribs).

Luckily for us, parts of that bed were exposed at more workable levels. Some of us actually found some bones, and not just the usual sirenian ribs and vertebrae, but we found two scapulae, probably belonging to the same individual! One of them, seen below, had something else in the matrix. When I turned it around there was a desmostylian molar fragment, the first one we know about from this formation!! So with that, I have actually found and collected nearly one of every group of marine mammals (at least the ones from the northern hemisphere)!

One of the sirenian scapulae from La Purísima, kind of small compared to other sirenians, a juvenile? a small species of sirenian? It remains to be sorted out!

More entries to come, so stay tuned!!

For past entries of this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Dispatches from the field: Baja California, Pt. 3

Dispatches from the field: Baja California, Pt. 3.5

Dispatches from the field: Baja California, Pt. 4

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.

Dispatches from the field: Baja California, Pt. 4

Having almost finished at the locality in the bay we headed inland, to look at additional exposures of the early Miocene Isidro Formation. We went to an area called Mesa El Aguaje. There we could see the Isidro Formation (the light colored units) overlain by the volcanics of the Esperanza Basalt (the dark colored rock over the Isidro).

Its hard to decide where to look for fossils when there are such extensive outcrop. So we decided to go along a dry riverbed, where on the sides we could see the exposures of the Isidro. At one point we saw some bones, so we started to dig.

Our efforts paid well, we found a fragment of mysticete jaw and part of a pinniped forelimb and many shark teeth. If you click on the picture for the larger version you can see where we were digging.

For now we're done at this locality as we still have to go to La Purísima to look for the type locality of Dioplotherium allisoni. So, stay tuned!!

For past entries of this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Dispatches from the field: Baja California, Pt. 3

Dispatches from the field: Baja California, Pt. 3.5

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.

Dispatches from the field: Baja California, Pt. 3.5

Almost forgot about this. One of the interesting things that we see when we walk along the shores of the Pacific Ocean in this region is marine vegetation that has washed on the shore.

To the left (in green) is Zostera a seagrass which is widely distributed across the world, including Baja California. Kelp, the long brown one (with the Zostera tangled in its base), is a brown algae that also grows in this region.

Dugongid sirenian, which inhabited this region during the early Miocene most likely ate a variety of marine vegetation. Species, like the dugongine Dioplotherium allisoni, probably fed on seagrasses, whereas the hydrodamaline Dusisiren reinharti, likely fed on kelp, both species are known from the . So the interesting thing is that nowadays we still find the same, or at least very similar, food source that these sirenians used. So the seacows are gone, but the food remains the same.

Previous entries in this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Dispatches from the field: Baja California, Pt. 3

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.

Dispatches from the field: Baja California, Pt. 3

Today we set out to collect the partial mandibles that were next to the skull that we collected yesterday. We are still not sure which taxon it is (we have some ideas) but to know for sure we'll have to wait until the skull is completely freed from its rocky tomb. But first, we decided to do some prospecting to the east of where the sirenian skull was.

We didn't find anything in the units east of the sirenian skull site so we decided it was time to collect the mandibles. Also, there were some postcranial material that we had started to collect, but with the excitement of finding a skull, they had been neglected. Well, not any more. After this we were supposed to be done with this locality, and could get ready to head out to other localities we've plan to go.

As it sometimes happens, our plans changed. After collecting the fossils we set out to review the stratigraphy of the section we've been prospecting, actually, some of us, Larry and Fernando, had done it, and they wanted our opinion on it, and we could also know exactly how to refer to the units where we were collecting our specimens. At the beginning, near our camp, I stayed behind digging a rib, from one of the lower beds of the formation, after a while I stopped and joined the others, but keeping in mind that on the way back I wanted to collect the rib. So, on the way back, I started digging the rib and to my surprise found something even better next to it. Part of a sirenian skull! Another one!

The fragment that I found consists of part of the left maxilla (see the molar in the maxilla, above), and as I and some of the others kept digging more stuff kept coming out. As the sun settled we kept finding more and more bones along this one bed, next to the sirenian maxilla there were other cranial material most likely belonging to the same individual, obviously the sirenian was juvenile as the skull is disarticulated. Other fossils that we've collected so far include a baleen whale vertebra and some dolphin vertebrae, so in one small spot we've got three different marine mammals. It was another good day of collecting today!

Previous entries in this series:

Dispatches from the field: Baja California, Pt. 1

Dispatches from the field: Baja California, Pt. 2

Fieldwork in Baja California was made possible through an NSF EAR grant to D. P. Domning & L. G. Barnes. The text in these posts reflect my own opinion and not those of the granting agency or institutions to which I’m affiliated.