Finding Shark Teeth Along the Shores of Lake Alajuela

On Monday of this week, I was fortunate to make several interesting fossil finds along the shores of Lake Alajuela, in Chagres National Park. The water levels were very low, which facilitated the finding of vertebrate fossils by exposing the correct sediments which they can be found in. Less than 30 minutes into the field day, I came across a chunk of fossil turtle, and after some digging, realized that there was a lot more turtle there. After working on the turtle for a while, I started walking along the exposed banks of the lakeshore, following the fossiliferous sediments.

I walked for much further than I had expected to be able to, given the low lake levels and large amount of exposed outcrop; then I found something really neat. The lake water was nearly lapping the fossil itself, so I decided to collect it in case the water levels rose or a wave came by unexpectedly and washed it away. It was a beautifully-preserved Carcharocles megaladon tooth. Certainly not a big one by any means for a “meg” (especially compared to the hand-sized behemoths that can be found in Florida creeks), but still a large shark tooth nonetheless. It was an exciting moment, finding my very first “meg” tooth in Panama. Hopefully I can find more on my return trips to Lake Alajuela this summer before the end of the internship!

C. megaladon tooth from the shores of Lake Alajuela, Chagres National Park. Photo courtesy of E. Whiting.

C. megaladon tooth from the shores of Lake Alajuela, Chagres National Park. Photo courtesy of E. Whiting.

Meet Robyn!

Hola! My name is Robyn Henderek and I am one of the four PCP-PIRE Summer 2014 interns. I am a rising senior at Lafayette College in Easton, PA double majoring in Geology and Anthropology. Within the field of geology, I am interested in studying paleo-environmental reconstruction especially pertaining to human evolution during the Plio-Pleistocene in East Africa. This past spring, I had the pleasure of working with Dr. Craig Feibel of Rutgers University on the Hominin Sites and Paleolakes Drilling Project. My job was to record the stratigraphy of a 200-meter long continental core from Nariokotome, Kenya. In the same vein, I recently returned from a three month-long field course in the Turkana Basin, Kenya where I studied pre-historic archaeology, vertebrate paleontology and geology.

Robyn excavating a juvenile Deinotherium from Turkana, Kenya.

Robyn excavating a juvenile Deinotherium from Turkana, Kenya.

In spite of this, my interest in rocks began long before I could even pronounce conglomerate. The rocky coast of Maine first captured my attention not for it’s scientific significance but because the weathered schists and beautiful white granite intrusions made for a great playground. I would spend my summer days hopping from rock to rock, looking in the tide pools for crabs and starfish while exploring the small world I lived in.

When I got older, I learned how much more interesting our planet is, both in time and space. Now, I am so excited to be here in the Panama Canal Basin this summer exploring the Miocene.

Gamboa and Pipeline Road Adventure

This morning I had the privilege to go birdwatching in one of the world’s most famous Neotropical rainforest locations: Pipeline Road, just outside the small town of Gamboa in central Panama.

Sign marking the beginning of Pipeline Road (Camino del Oleoducto in Spanish) in Gamboa, Panama. Photo courtesy of E. Whiting.

Sign marking the beginning of Pipeline Road (Camino del Oleoducto, in Spanish) in Gamboa, Panama. Photo courtesy of E. Whiting.

This has been something that I’ve wanted to do for a long time, so finally getting to Gamboa and hiking up the road through the tropical rainforest was spectacular. I also paid a visit to the nearby Panama Rainforest Discovery Center (PRDC), and was quite impressed.

It’s said that some people have seen over 300 species of birds on Pipeline Road in a single day; this may seem exorbitant (and ridiculous), but it’s not surprising if you go and see the incredible avifaunal diversity that exists there in person. I was blown away by the number of bird species that I saw, not to mention all of their beautiful and multicolored plumages. I wasn’t used to the birding style though, and was thrown off at first when I hardly saw or heard any birds upon entering the rainforest. Many Neotropical rainforest birds often appear in small flocks with multiple species all at once, followed by long periods of quiet and seemingly little bird activity. There are exceptions to this (such as with toucans and kingfishers, both of which I saw and heard along the road), but it’s surprising how different the birding was compared to back home.

Among my biggest “hits” today were an Oscellated Antbird, Chestnut-mandibled Toucan (heard, but unfortunately not seen), Broad-billed Motmot, Golden-collared Manakin, and loads of stunning hummingbirds at the nectar feeders on the porch of the PRDC’s visitor center.

Hummingbirds at the Panama Rainforest Discovery Center's visitor center nectar feeders. Photo courtesy of E. Whiting.

Hummingbirds at the Panama Rainforest Discovery Center’s visitor center nectar feeders. Photo courtesy of E. Whiting.

I highly recommend a visit here if you’re interested in seeing rainforest wildlife (especially birds) in Panama! It was first class, and the rainforest canopy tower on their grounds was incredible too! I will definitely be returning to Gamboa again before I leave Panama this summer!

After visiting Gamboa, I returned home to Panama City to rest and prepare for the next week of fieldwork along the Panama Canal. It will surely be an interesting and productive week, especially after finding/rediscovering new localities last week. One of my top priorities early this week is to return to and collect a fossil turtle that I discovered late last week. Who knows what other awesome fossil treasures we might find next week!

From Colón to Corozal

Greetings and Happy (belated) American Independence Day from the Summer 2014 PCP PIRE Intern cohort! Last night we celebrated the 4th of July with classic American cuisine including hotdogs and apple pie. We hope you had a safe and enjoyable celebration as well!

Happy 4th of July from the Summer 2014 PCP PIRE Interns! Photo courtesy of E. Whiting.

Happy 4th of July from the Summer 2014 PCP PIRE Interns! From left: Wesley, Robyn, Michelle, and Evan. Photo courtesy of E. Whiting.

This week, we travelled from the Pacific to the Caribbean with a giant snake, collected and prospected along the Panama Canal, and screenwashed sediments for vertebrate microfossils.

Our week began at STRI in Panama City, where we closed up crates containing the world’s second life-sized model of Titanoboa, the largest snake that ever lived. It was discovered nearly a decade ago in a massive coal mine in Colombia, and was first published and named in 2009. It has captivated the world ever since, inspiring a documentary film, a (first) life-sized model (currently on exhibit at the University of Nebraska State Museum in Lincoln, Nebraska, USA; formerly on exhibit at the Florida Museum of Natural History in Gainesville, Florida, USA), and even a cell phone game! Once the crates were ready, they were loaded via forklift into a truck that went to the Caribbean city of Colón; from there it will be taken by boat to Colombia for further exhibition (it was formerly on exhibit at Albrook Mall in Panama City).

Titanoboa exhibit at Albrook Mall in Panama City. Photo courtesy of E. Whiting.

Titanoboa exhibit at Albrook Mall in Panama City. Photo courtesy of E. Whiting.

Following our day of packing and transporting Titanoboa to Colón, we resumed our collecting efforts along the Panama Canal. This week wasn’t as successful as the previous, unfortunately, but sometimes that’s just the way it goes. Finding fossils in the tropics is difficult, and there’s always an element of luck that plays into it. We still collected some mammal and croc teeth, though, and I found a partial turtle shell on Thursday that I’ll return and collect early next week after making a plaster jacket for it. Also on Thursday, University of Florida Ph.D. graduate student Aldo Rincon, PCP PIRE Intern Supervisor Jorge Moreno-Bernal, and I scouted for new (and rediscovered old) fossil localities along the Panama Canal. We were very successful, and have significantly increased the number of available outcrops to prospect and quarry at.

We finished our work week at a facility in the canal-side neighborhood of Corozal, where we screenwashed sediments bagged and collected from one of our most productive Panama Canal localities, in search of vertebrate microfossils. After setting up the screenwashing apparatus and preparing the sediment to be washed, we worked through several bags and produced concentrate that will be “picked” for microfossils later on (I found a number of small caiman teeth during screenwashing though, which was exciting). It was a nice end to our work week, and a great way to start our 4th of July celebration. Thanks for reading, and farewell until my next blog post!

Screenwashing (Down and Dirty)

A follow up to yesterday’s post.

As mentioned yesterday, large bones and fragments are easy (relatively) to find in the field. Collections include turtle shell, ungulate jaws, rhinoceros and even crocodillian skulls. Hidden within the same layers we find these bones, however, are even more fossils. These fossils, which include teeth and bone fragments of rodents, bats, and other small vertebrates, are often the size of the sediment grains in which we dig, if not smaller.

In order to find these micro-specimens, we must separate bone from sediment.

Bags of sediment, collected from sites in which we have found other, larger fossils.

Sediment bags are labeled with locality ID and collection date.

We separate trash from treasure in a process known as wet sieving, or screenwashing. Sediments are soaked thoroughly and run through a series of wooden boxes with mesh screen bottoms of increasingly smaller sizes. Running the samples through these sieves allows dirt and smaller grains of rock to fall through the screens, leaving behind larger fragments.

The interns prepare a bag of sediment for washing.

 

Soaked sediments are deposited into the first of three screens. Large rocks will be left behind, while small fossils and clay sized particles are washed down into the next layer.

Not every location in which fossils are found is necessarily a good location for screenwashing. Sites comprised of well consolidated rock can hardly be used – instead a site is needed that consists of soft sedimentary rocks such as mudstone, claystone, and siltstone. These can easily be broken down and washed.

 

PCP PIRE 9 (5)  PCP PIRE 9 (3)

PCP PIRE 9 (14)PCP PIRE 9 (9)

Following the washing, sediments are lain down to dry.

Jorge Moreno, PIRE intern supervisor, holds a collection of crocodile teeth found in a preliminary search of washed sediments.

Once dry, sediments are bagged and labeled so they can be sent for further sorting and inspection under a microscope.

Sediments from the sacks, washed and labeled, awaiting inspection under microscope.

 

Azuero Peninsula Adventure (Retrospective)

It was great to meet and work alongside other scientists, interns, and students from the Smithsonian Tropical Research Institute (Ancón, Panamá) and University of the Andes (Bogotá, Colombia) who we (the Summer 2014 PCP PIRE intern crew) joined a month ago in the Azuero Peninsula of southwestern Panama for a geological mapping field course. Based in the small coastal town of Torio, we went on daily excursions to different localities seeking new geological knowledge about this relatively unexplored (geologically speaking) region of Panama. For more on this trip, please check out the upcoming June/July PCP PIRE eNewsletter.

I’m a vertebrate zoologist by training, with only a small geology background (mostly involving laboratory methods and samples), so learning field geology skills such how to use a Jacob’s Staff and Brunton Compass as well as how to measure and describe stratigraphic sections with in-field hand samples and rock outcrops through this experience were very beneficial to me as a developing interdisciplinary scientist. I also collected my first plant and invertebrate fossils from the Neotropics along Torio Beach, including some complete fossil seeds and sea urchins!

During my time in Azuero, I made several new Colombian friends, improved my Spanish language skills, and went on many adventures (some quite harrowing) that I won’t soon forget.

Perhaps the day in Azuero that will stick in my memory the longest was when myself, two University of the Andes students, and their instructor followed a local Panamanian guide down the gullet of Rio Torio in search of a geologic contact between Cretaceous limestone and basalt. We trekked/hacked our way through the tropical rainforest on seldom-used, overgrown paths in order to reach the river, and walked/waded upstream from there. We had numerous encounters with rapids and waterfalls, which sometimes required leaving the river to climb around these obstacles on steep, slippery limestone cliffs and boulders; sometimes, however, we went right through or fell into the rapids (and got a thorough soaking in the process). We stopped periodically at rock outcrops along the riverbanks to hammer out some hand samples to inspect with our hand lenses, but kept going through the river laced with slippery limestone and rainforest on either side. After reaching the calmer headwaters of the river, we left it behind and hiked up mountain cow pastures to one of the tallest points in the region, in order to get a better view of our surroundings and consult our topographic maps. It was one of the most beautiful sights I’ve ever seen, looking across the landscape of green rolling hills, rivers, beaches, and the Pacific Ocean. I was completely exhausted, but had to recover quickly for the harrowing return trip down from our high vantage point and back through Rio Torio – this time in the middle of a torrential downpour which infused the river with energy and clouded it with sediment…

From wading through raging rivers and hiking up mountains searching for rock outcrops, to racing the rising tides to collect fossils along the beach, all in the company of new international friends and colleagues, my Azuero experience was unforgettable.

Who You Gonna Call? Summer Interns!

While Evan, Jorge, and Aldo ventured out into the field as per usual, Wesley, Robyn, and myself took a detour to our offsite facility in Corrazal. Our building there houses neatly organized samples as well as equally organized bags of dirt. Dirt? Yes, dirt.

Sediments, if we should use a more technical name, are taken from fossiliferous layers in sites from which we have been excavating. While our time in the field allows us to find many samples, smaller specimens often slip through our fingers (quite literally).

What is to be done about such a loss? Sediments from these sites are collected and transported to sites such as these, where they are washed through a careful process referred to as screen washing.

Having collected a hefty amount of sediment from a few of our most productive sites, we the interns have been excited to begin the screenwashing process. Only one thing stands in our way – cleaning our site!

A shot inside the rooms of the facility. Samples are housed in plastic crates, carefully labeled and arranged by date and location.

The “before” picture – broken crates, unlabeled samples, torn bags, piles of dirt, and an unlucky anthill litter our workspace.


The “after” picture – the salvaged samples have been newly labeled and stored safely indoors and our workspace is clean and ready

As Jorge (PCP PIRE intern supervisor) and Evan (PCP PIRE intern) are still in the field, we must postpone the commencement of screenwashing until tomorrow morning – stay tuned!

Tuesday Afternoon

A national holiday has come and gone. Yesterday marked the inauguration of the new Panamanian president. Stores and services closed earlier than usual, or never opened at all. If one were to have peered into the city, through the streets of Cinco de Mayo (marketplace), past the Mercado de Mariscos (fish market) and just west of Casco Antiguio (Old Panama), one would have seen an ebb and flow. Skirts and shirts and hair and hands pressed against each other in a crowd, edging towards the city. A mile or more of road had been shut down along the edge of the towers and the start of the water, in the intersection between canal and ocean. Newly erected stages housed singers and dancers, tents and vendors lined against the street, and carnival games interspersed for a street fair in celebration.

The interns sip on 50c raspados (snow cones)!

One of the few stages lined up against the pier – artists from around the country had been and would continue to perform throughout the day.

Clouds rise and the sun falls behind the canal.

The buildings of Casco Viejo – the historic district of Panama, built and settled in 1600s.

Often our trips to Casco Viejo include a stop at Granclement Ice Cream and Sorbets. Todays flavors: guanabana and dulce de leche.

Elephants in Panama?

Dr. John M. Turner, an optometrist from Hattiesburg, MS, grew up in the Panama Canal Zone.  As a youth he collected fossils as a hobby.  Dr. Turner shared his fossils, including the tooth of a Gomphotherium (extinct relative of the elephant) during a chance encounter with PCP PIRE Principal Investigator Bruce MacFadden.  This exciting new find, and the story behind it, was profiled in two parts in the PCP PIRE eNewsletter (Part 1 | Part 2).  Dr. Turner’s fossil finds were also recently profiled in the Hattiesburg American.  We are grateful to Dr. Turner for his generosity with his fossil finds and his willingness to tell his story.
Below is a flickr album with photos provided by Dr. Turner from his time in Panama. Click on the image below for a slideshow, or follow this link for them to appear in a separate window with captions.

A Busy First Week Along the Panama Canal

This past Friday, we finished cataloging all of the fossils that we collected during the past week of fieldwork, which totaled over 60 specimens!

Fossils collected during our first week of fieldwork along the Panama Canal and Lake Alajuela. Photo by E. Whiting

Fossils collected during our first week of fieldwork along the Panama Canal and Lake Alajuela. Photo courtesy of E. Whiting.

It was a busy and productive first week of collecting along the Panama Canal and shores of Lake Alajuela (the previous 3 weeks were spent conducting geological fieldwork in the Azuero Peninsula, see our May 29 blog post for more details); our first week of fieldwork in the canal basin, led by PCP PIRE Project Manager Dr. Aaron Wood, yielded numerous fossil mammal teeth, turtle shell fragments, a snake vertebra, a partial crocodylian skull, and a camel jaw with several teeth!

Earlier last week, I made my first plaster jacket for a fossil specimen in Panama! On Monday, I found a very fragile fossil camel jaw with most of its teeth intact, but a tropical downpour prevented us from being able to collect it. A few days later, the weather finally held out long enough for us to return to the site and make a plaster jacket to protect the camel jaw for safe and secure transport back to the lab. The process of making a plaster jacket in the field can be seen in the PCP PIRE March 2014 eNewsletter.

Overall, it was a very good first week in the Panama Canal and surrounding areas, following our 3 week adventure in the Azuero Peninsula. Hopefully we’ll have a lot more success in the Panama Canal basin as this summer continues!