Paleontologists have unearthed a 15 million-year-old skull belonging to a type of whale that, according to those overseeing the dig, has long gone extinct.

The discovery was made along the 150-foot-high banks of the Potomac River on the grounds of Virginia's Stratford Hall Plantation, the birthplace of Robert E. Lee. Known as "The Cliffs," the formation represents a rare geological phenomenon found in just three other places in the world -- the Los Angeles basin, Austria and Belgium.

Dating back to the Miocene Epoch, approximately 17 to 10 million years ago, they are composed of compacted sea matter and were formed when rising land replaced the ocean that once covered Stratford. As it happened, this series of events provided just the right set of circumstances for the fossilization of animal remains, according to site officials.

Today, this is evidenced in the thousands of shark teeth found in the area, as well as remains of saltwater crocodiles, sea cows, gopher turtles, rays and whales.

The latest whale skull has caused a stir, however, as one of the largest ever collected locally. In all, the baleen whale skull measures 6 feet long, suggesting the whole creature would have been 25 feet, if not more. According to those behind the project, the rest of the skeleton is still lodged in the earth, though plans to free it are currently underway.

In the meantime, the skull has been transported via boat and with the help of more than 30 individuals to the Calvert Marine Museum where researchers plan on cleaning the specimen and subjecting it to intensive examination.

Going forward, John Nance who led the dig told the Washington Post that the excavation of the rest of the skeleton will take roughly two weeks.