Vincent L. Santucci, Senior Paleontologist
NPS Paleontology Program, Washington D.C.
For approximately fifteen million years, the remains of a prehistoric dolphin lie quietly preserved within layers of marine sediments exposed today along the Potomac River in eastern Virginia. On March 16, 2020, National Park Service rangers and paleontologists converged upon George Washington Birthplace National Monument, Virginia, to coordinate the emergency recovery of the fossil dolphin.
The fossil-rich sediments at the monument were deposited along the ancestral Atlantic coastline for millions of years during the Miocene epoch, which spanned from about 22 to 8 million years ago. For several years park rangers have been regularly monitoring the emergence of fossils within the rapidly eroding cliffs along the shoreline at the monument. Some barely exposed fossil bone discovered and documented the previous year, by the monument’s chief ranger Tim Sveum and NPS paleontologist Justin Tweet, was now more visible revealing identifiable skeletal remains. Monitoring and repeat photography of the freshly exposed fossils was undertaken by park ranger Wesley Spurr who observed that the high rate of erosion resulted in the loss of three bone elements over a two-week period.
Photos of the fossils visible at the surface were forwarded to paleontologists Vincent Santucci and Justin Tweet (NPS Paleontology Program), and Stephen Godfrey (Curator of Paleontology, Calvert Marine Museum), who confirmed the remains of the ancient marine mammal. It was also apparent that these important fossils were “at risk” and in imminent danger of being swept away. Close communication between the park and the paleontologists led to the decision to coordinate the emergency recovery of the specimen.
On March 16, 2020, a rapid response team of paleontologists (NPS and Calvert Marine Museum) and park rangers met at the monument to support the field collection and rescue of the “at risk” fossil. During the team’s deployment to the fossil locality, a second and more complete fossil dolphin skull was discovered eroding from the cliffs not far from the first specimen. This second specimen was determined to be at risk and was also collected on the same day.
Under the direction of Dr. Stephen Godfrey, the two fossils were excavated from the soft sediments and stabilized in the field using plaster jackets (Figures 1, 2, 3). According to Dr. Godfrey, “One specimen was a jumble of vertebrae, ribs, and a partial skull. The second specimen was an isolated but nearly complete skull. This second specimen was mysteriously encased in hardened sediment, which helped to preserve the skull mostly intact, but will make it much more difficult to prepare. The skull of this kind of dolphin had an extremely long snout that they would have used to capture fishy prey.”
After several hours of work, the two fossil specimens were successfully loaded onto a boat to begin their new journey to the Calvert Marine Museum for preparation, curation and study (Figure 4). Dr. Godfrey reported, “I was thrilled to be involved with the NPS in the recovery of the fossilized remains of two 15 million-year-old dolphins.” The fossil specimens are believed to belong to an extinct family of long-nosed dolphins (Eurhinodelphinidae) that inhabited the Atlantic coastline during the Miocene.
The successful rescue of the dolphin fossils was in part due to the advance planning and logistical support coordinated by George Washington Birthplace National Monument Chief Ranger Tim Sveum. Tim and his rangers have proactively monitored the fossil-rich cliffs at the monument for several years and were integral in the development of the monument’s Paleontological Resources Monitoring Protocol. Given the race against time and natural processes which were impacting the fossils, Tim was able to ensure safety of the team in consideration of the weather, tides, and even the necessary precautions related to the current COVID-19 public health issue.
As the fossil rescue team wrapped up their long day of field work, Chief Ranger Sveum stated, “The NPS Paleontology Program developed a fossil resource monitoring protocol a few years ago which resulted in the discovery of a dolphin skeleton early on as it was eroding out of the cliffs. Our partnership with the NPS Paleontology Program and the Calvert Marine Museum allowed an emergency excavation of a resource that would have likely been lost forever to be saved for many generations to come.”
Park staff and paleontologists work together to maintain fossils for scientific study and public education. It is exciting to find a fossil, but important to protect it. If you find a fossil in a park, leave the fossil where it is, take a photo, and share your discovery with a park ranger.
Please be aware that the collection, removal or disturbance of fossils at George Washington Birthplace National Monument, and other National Park Service areas, is prohibited except in cases where an approved permit has been issued by the NPS.
Series: Park Paleontology News - Vol. 12, No. 1, Spring 2020
Last updated: March 27, 2020