Erosion along the Chesapeake Bay cliffs in Calvert County has exposed another ancient whale skull, and students from Harrisburg, Pa., were expected to help scientists dig the fossil from the heavy clay sediments.
Only a small portion of the back of the skull is visible, said Stephen Godfrey of the Calvert Marine Museum in Solomons. But the Miocene-era fossil is probably 16 million years old, and likely belongs to an extinct family of small whales that swam in what were then Atlantic coastal waters teeming with marine life.
The type "almost certainly gave rise to the filter-feeding whales called Balaenopterids, that include fin, blue and sei whales," he said. But judging by the size of the skull — perhaps 4 or 5 feet long — this one was small, similar to today's minke whales.
The skull was spotted several months ago, south of Chesapeake Beach. It rests in heavy clay about 4 feet from the base of the cliff. Scientists covered it with clay to conceal it from amateur fossil hunters while they waited for a clay overhang to drop and make the site safer for an excavation.
But high water and wave action exposed the fossil, and the overhang remained. So a crew from the museum returned Friday to remove the overhang and make the site secure for the dig Saturday.
The Calvert Marine Museum collects three or four whale skeletons from the Calvert Cliffs each year, Godfrey said. One, dug from the cliffs near Chesapeake Ranch Estates in 2009, sparked a lawsuit when the local community association discovered that the museum's paleontologists were digging on the association's property without permission.
In April, a judge ordered the museum to pay the community $1 for trespassing and $10,000 for the 10-million-year-old fossil.
This time, Godfrey said, the museum "early on received permission from the landowner ... so as not to repeat the … debacle."
Paleontologists will be assisted by eight undergraduates, five of whom are studying evolution at the Harrisburg University of Science and Technology.
Professor Robert E. Furey said he's been taking his students on field trips to Calvert Cliffs for years.
"It's well and good to learn about evolution and read about it in a book," he said. But "when you go and remove the remains of animals this size, and see how much ground has been laid down on top of it, and how old it is, it brings home the concepts of evolution and deep time. I'm hoping they have some sort of epiphany."
Godfrey and the museum's collections manager, John Nance, are happy to have the extra labor on hand to remove clay and encase the fossil in plaster for transport to the museum. They also hope everyone will learn something about the region during the Miocene and the creatures that lived here.
"For some reason, when we get down into the older part of the Calvert Formation, into the 16- to 20-million-year time frame along the Calvert Cliffs, whales are very rare," Godfrey said. "When we move up in younger sediments, baleen whale skulls become more common. I don't ever remember collecting a whale skull from this lower section. It's a mystery, because we think they should be here, like everything else is here," including dolphins, sea cows and myriad shellfish.
The collection and study of the skull will allow scientists to identify it, provided that its kind has been found before.
"It's possible this represents a new kind of baleen whale not previously described from Calvert Cliffs," he said. That would expand science's understanding of the creatures that lived in Maryland's seas during that period and the conditions in which they lived.