While others go to Caribbean beaches to swim and sunbathe, Nick Pyenson visited one recently for a fast-paced, exhausting four-hour fossil dig. Not only was it his idea of fun, it was part of his job.
The paleobiologist, from the National Museum of Natural History, excavates fossils of marine mammals (when he is not studying specimens in museums and writing papers). In Piña, Panama, last month, as the incoming tide threatened to cover their work site, Pyenson and graduate student Jorge Velez-Juarbe raced to remove the 6 million to 7 million-year-old skull of an extinct toothed whale.
They were accompanied by a team from the Smithsonian Tropical Research Institute in Panama, including researcher Aaron O’Dea, who had told them about the discovery.
The timing was carefully executed. “We knew when the lowest low tide would be,” says Pyenson. “The next low tide that would have been usable would be next year. We had a one-day window for another 12 months.”
The dig team descended on the beach with hammers, pick axes, dental picks, plaster, gauze and glue—plus still and video cameras to record the event, which you can watch in time-lapse form.
As they dug, Pyenson realized the fossil was bigger than first thought. The lower jaws lay beneath the skull. Also there were hints of the ear bone. The number of bones meant the team was even more pressed for time.
Finally, the group removed all the rock surrounding the fossil except for a pedestal-shaped piece. They covered the top of the fossil with a plaster cast called a jacket. Then they broke the rock pedestal to dislodge the skull, turned the skull upside down, hauled it atop a tarp to dry sand and made a jacket for the bottom.
Encasing a fossil in plaster “is one of the more satisfying parts about paleontology,” says Pyenson. “This is where art meets science because understanding how to do a jacket is not really a scientific procedure. It’s more of an aesthetic procedure that is better suited for art students.
“When we were up on the beach finishing the jacket—that was a good moment.”
This skull represents the first significant find from this area of the world for fossil whales, to Pyenson’s knowledge. “We do know about fossil sea cows from elsewhere in the Caribbean. . . . But not so much for whales, which is kind of surprising because fossil whales show up everywhere in the world,” he says.
The jaw of this predator contains unusually serrated teeth, meaning it probably belongs to a group of toothed whales called Squalondontidae. Further lab study is needed to positively identify it.
The fossil is still in Panama, awaiting delivery to the Natural History Museum. Once it arrives later this year, it will be placed in the FossiLab, where visitors will be able to watch staff remove the jacket and prepare the fossil for study and exhibition.