Bruce MacFadden hacks his way through the gray clay of Panama with a prospector’s hammer, carving out a perfect protrusion to sample its magnetic orientation. He seems oblivious to the massive container ship gliding almost silently through the muddy brown waters of the canal just yards away.
Finally, he has a piece that will work. It’s about three inches in diameter, protruding in such a way that he can carve a flat surface on it with his well-worn sheath knife. That done, he pulls a geologist’s Brunton compass from his bag and lays it atop the rock. He aligns the needle with magnetic north, then uses the compass’ sturdy metal case as a straight edge to record the sample’s alignment with a pencil.
The Earth’s magnetic field has reversed many times over its history, so by determining the orientation of this layer of rock, MacFadden and his team can accurately date the fossils they find here.
“In order to find out the age of the fossils, we find out the age of the rocks that the fossils are contained in,” he says between swings. “We use the pattern of magnetic reversals in the past to tell us where we are in the geologic time scale.”
He gingerly pries the chunk from the hillside, hoping it won’t crumble in his hands. He assigns it a sample number, records it in his field notebook and hands it to a student to wrap for shipment back to Gainesville for testing.
One down, 24 to go.
Some samples require a heavy pickaxe to tease them out, MacFadden’s breathing becoming more labored with each swing. The sweat beads on the paleontologist’s forehead beneath his hardhat and a safari shirt sticks to his skin. Here in Panama, just 9 degrees north of the Equator, the July sun is merciless, even at 9 a.m.
As the principal investigator on numerous projects and with a host of graduate students to mentor, MacFadden has to maximize his opportunities to get into the field because he still has many scientific questions to answer, and time is running out.
You wouldn’t think a couple of months would make much difference to scientists who study fossils that are 20 million years old. But while geologic time is slow, the jungle is unrelenting.
For 100 years, the Panama Canal has served as the gateway between the Atlantic and Pacific oceans, but as international sea trade has boomed, ships have grown ever larger, with many now exceeding the capacity of the canal’s locks.
So, in 2007 Panama initiated a $7-billion project to expand the canal, adding two new, larger locks on both the Atlantic and Pacific sides and widening and deepening the canal at numerous locations. The expansion will more than double the canal’s capacity, allowing ships up to 1,200 feet long and 160 feet wide to make the transit. It will also allow ships to pass each other, even at the tightest spots, ending the alternating one-way system now employed.
While the expanded canal is expected to be a boon to Panama and international trade, it is the construction that most interests MacFadden and his colleagues. The contractors are doing all the heavy lifting for the paleontologists, excavating more than 150 million cubic meters of soil.
“This expansion is providing a once-in-a-century opportunity to access new rock outcrops rich in fossil diversity,” MacFadden says. “But within a year after the excavations are finished, all the outcrops will be covered by grass and no longer accessible to our team, so we’re racing against the clock for the next couple of years, trying to discover everything we possibly can.”
And there’s a lot to discover in Panama, because millions of years ago Panama was the place where North met South.
“Where we are right now was the southernmost tip of North America,” MacFadden says. “Just to the south, between here and Colombia, there was a very deep seaway called the Central American Seaway that was a barrier to animals dispersing into South America and animals coming from South America into North America.”
Then, about 4.5 million years ago the two continents came together with the formation of the Isthmus of Panama, which served as a bridge for animals to cross in both directions in what’s called the Great American Biotic Interchange.
“We’re interested in the kinds of animals that lived in this area before the formation of the bridge, about 19 to 21 million years ago, during the time period geologists call the Miocene,” MacFadden says. “That’s the age of the fossils we’re finding from the outcrops exposed along the canal.”
For much of his career, MacFadden has focused on the evolution of horses, publishing dozens of papers in prestigious journals and authoring what is considered the definitive book on the subject.
Then, in 2002 he was invited to tour Panama with researchers from the Smithsonian Tropical Research Institute, or STRI. The Smithsonian has been active in Panama since 1910, during U.S. construction of the canal, and STRI maintains extensive research capabilities throughout the country.
Initially, MacFadden just planned to work on fossils Smithsonian paleontologists and Canal Zone geologists had collected in the 1960s and ‘70s that had never been described, but when a rich deposit of fossils was discovered in 2004 during construction of the new Centenario Bridge carrying the Pan-American Highway over the canal, he proposed new digs.
“I had some small projects working along the excavations for Centenario Bridge, but they allowed us to develop some partnerships down here,” MacFadden says.
When Panama announced the canal expansion in 2007, MacFadden realized it would provide access to even more of the fossil deposits they had been studying near the bridge.
“I realized that the expansion was going right through the same age fossil deposits that we had been digging for several years,” he says. “This presented an extraordinary opportunity to advance understanding of the ancient biodiversity of this area.”
The partnerships MacFadden had been building with these smaller projects all came to fruition in 2009, when the National Science Foundation announced a new cycle of Partnerships in International Research and Education, or PIRE, grants.
“When the solicitation for the PIRE grants came out, it was just what I was looking for in terms of being able to fund a large, complex, multinational research and education project focused around the Panama Canal,” he says.
But MacFadden and his colleagues at the Florida Museum of Natural History — museum director Doug Jones and paleontologist Jon Bloch — knew competition for the PIRE grants was going to be fierce and that their proposal needed to be comprehensive.
“Think about what PIRE stands for — Partnerships in International Research and Education,” MacFadden says. “NSF takes each one of those four parts of that program very seriously.”
Drawing on relationships built over decades of research, the team began pulling together elements that addressed all four components of the PIRE mission.
Along with STRI, they partnered with the Authoridad de Canal de Panama to do the excavations and collect geologic and paleontologic samples from the canal. And they partnered with SENACYT, the national science foundation of Panama, to support Panamanians, some of whom are UF students.
They included opportunities for American students to travel to Panama and Panamanian and Colombian students to travel to the United States.
And they planned outreach programs that would take the research to the general public.
In July 2010, NSF awarded UF $3.8 million for the Panama Canal Project PIRE and the digging began in earnest.
Post-doctoral researchers and graduate students are the backbone of the PCP-PIRE Project and UF has assembled a team with diverse expertise.
“Every one of my students is better at something than I am and that’s the way it should be,” MacFadden boasts like a proud father. “Within this team everybody has a different expertise. If you need a good anatomist you go talk to Jorge Velez. If you want to talk about fossil sharks you go to Catalina Pimiento, if you need to know the age of rocks, you talk with David Foster, chair of UF’s geology department. If you want to understand about fossil horses or the Earth’s magnetic field, you talk to me. Each of us has both a general understanding of the broad field and a specific or focused expertise. That’s how you build a team.”
From their base at STRI in Panama and remotely from the Florida Museum of Natural History in Gainesville, post-docs Velez, Austin Hendy and Aaron Wood supervise more than a dozen graduate students doing much of the fossil gathering along the canal.
“The day-to-day discoveries are made mostly by younger members of the team,” MacFadden says. “We have student interns who go out in the field every day looking for fossils. They get out early in the morning, put in a half day of work before it’s either too hot or the rains come, then go back in and study what they found.”
There are three ways to collect fossils in the field — surface prospecting, quarrying and screen washing.
In surface prospecting, researchers walk along an outcrop looking for anything distinctive. It might be a bone or a shark’s tooth or a fragment of a sea urchin, depending upon where you are in the rock column.
“Surface prospecting is hot,” MacFadden says. “You’re walking along in the hot sun and you might go for hours and hours and not find anything, and then boom, you find something really cool, like a fabulous shark’s tooth or an animal that’s new to science.”
If there seems to be a concentration of fossils in one area, they settle in and start quarrying.
“Basically, instead of just walking along the surface we stay in one area and concentrate our digging,” MacFadden says.
The third way of collecting fossils is by bagging up the sediments, bringing them back to the laboratory and rinsing them through progressively smaller screens. Gary Morgan, a curator from the New Mexico Museum of Natural History and Science and UF alum, is the team’s lead scientist studying tiny fossils recovered by the screenwashing efforts.
It takes a great deal of patience and extremely sharp eyes to do this kind of work. What looks like just another rock to the average observer turns out to be the fossilized tooth of a prehistoric pig. While some finds are large, like a camel jaw, many are almost microscopic, like tiny fish teeth or snails. But they are all part of a giant jigsaw puzzle the researchers are painstakingly putting together in search of understanding about how life evolved in this important region of the planet.
The researchers have identified three main formations along the canal. The oldest — the Las Cascadas Formation — is about 21 million years old.
It was in this layer that doctoral student Aldo Rincon toiled for two years teasing fossils from the dirt, only to discover that many were from the same species of camel.
“When I came back to the museum, I started putting everything together and realized, ‘Oh wow, I have a nearly complete jaw,’” Rincon says.
Rincon’s discovery was important, MacFadden says, because it extended the range of this family of camels much farther south.
“The family originated about 30 million years ago and were widespread throughout North America, but prior to this discovery, they were unknown south of Mexico,” he says.
The middle formation — the Culabra — dates back to when oceans covered the area about 20 million years ago. Here there are fossils of marine mammals, sea urchins and sharks like the 60-foot-long Megalodon.
“Megalodon has been a large part of the project in terms of our understanding of marine life,” MacFadden says. “Megalodon is the subject of Catalina Pimiento’s doctoral dissertation in UF’s biology department and she has become the world expert on this shark.”
Modern sharks are known to have shallow-water nursery areas where the moms protect their babies, but based on her discoveries in Panama, Pimiento has shown for the first time in any fossil record the presence of Megalodon nurseries.
“The study provides evidence of Megalodon behavior in the fossil record,” says Pimiento. “Behavior doesn’t fossilize, but we were able to interpret ancient protection strategies used by extinct sharks based on the fossil record.”
The youngest formation is called the Cucaracha Formation and dates to about 19 million years ago.
It was here in March 2012 that intern Stephanie Lukowski discovered the jaw of a beardog just a few dozen meters north of the Centenario Bridge.
“At this quarry, the teeth and bone are usually either fragmentary or look like they’ve been ground down from being dragged along a river bottom by the current. This makes sense because these rocks were deposited by an ancient stream,” says post-doctoral researcher Aaron Wood. “What makes this discovery somewhat unique is how well preserved the jaw is. The jaw, rhino shoulder blade, and other specimens found close by — including a rodent jaw, two types of turtles and a horse tooth — are almost pristine. We hit the jackpot with this discovery in terms of information density.”
Mindful of the E for Education in PIRE, MacFadden and his colleagues built many education and outreach components into their original proposal, and they have since expanded them even more.
“Education outreach is a really important component of this project. It’s what NSF calls Broader Impacts,” MacFadden says. “Why should society care or benefit from the science that we’re doing? So we have many different components of our project that relate to Broader Impacts.”
One of the most innovative involves bringing middle and high school science teachers to Panama for several weeks each summer to get authentic research experience working alongside PIRE team members.
“It is possible, perhaps common, in the United States to become a science teacher without ever having participated in scientific research or practiced science beyond the classroom,” says Jason Tovani, a curriculum and instruction coordinator with the Santa Cruz (California) County Office of Education, who participated in the Panama field work in July 2013. “Through this experience, the practice of science came alive. We were thrust into the dynamic and exciting world of ‘doing’ science.”
His colleague, Jill Madden, a science teacher at Cesar Chavez Middle School in Santa Cruz, adds: “As a science teacher it has always been my goal to inspire young people about science. I want them to think of themselves as scientists by involving them in authentic experiences. I want them to be excited about what they study and to find the ways in which it is relevant to their lives. The PIRE Panama Project immersed me in exactly the authentic science education I seek to provide for my students. I was a student doing real science with real scientists.”
MacFadden marvels at the impact exposing the teachers to the Panama project has on children, calculating that the dozen teachers to participate so far have reached more than a thousand students each year. He also encourages his students to get into the classroom, and in 2013 Catalina Pimiento visited the Santa Cruz, California schools to talk about Megalodon, fossils and paleontology.
“For me, professionally, it’s really cool at this stage of my career that I could have an impact on so many schoolchildren,” MacFadden says.
Another outreach program involves the spectacular BioMuseo Panama.
Located on the Amador Causeway at the Pacific Ocean entrance to the Panama Canal in Panama City, the BioMuseo was designed by world-renowned architect Frank Gehry. Its colorful roof is visible for miles and is said to mimic the plumage of the country’s many tropical birds.
The museum, which is scheduled to open in mid 2014, is divided into eight galleries that trace the origin of the Isthmus of Panama and its huge impact on the planet’s biodiversity. They include a gallery illustrating the tectonic forces inside the Earth that formed the isthmus through three 14-foot-high sculptures.
In another gallery, titled “When Worlds Collide,” the great exchange of species between North and South America when the isthmus closed is illustrated through a stampede of animal sculptures.
As part of the PIRE project, UF faculty and staff have been collaborating with the BioMuseo for the past three years, providing them with fossil casts for display in some of the galleries, developing a temporary exhibit using fossils collected from the canal and providing a giant Megalodon shark jaw on long-term loan.
“Our Panama Canal PIRE project has been transformational in terms of research, international partnerships and outreach,” says Doug Jones, director of the Florida Museum of Natural History. “We have made fascinating paleontological discoveries that will allow us to rewrite the chronology and dynamics of the first land connection between North and South America. At the same time our growing international team of collaborators includes students, teachers, university faculty and museum professionals who have done an outstanding job of communicating the significance of these discoveries to the broader public.”
Source:
- Bruce MacFadden, Curator of Vertebrate Paleontology, (352) 273-1937
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This article was originally featured in the Spring 2014 issue of Explore Magazine.