A "janjucetus", an early type of baleen whale is seen in this undated handout photograph. reuters/Brian Choo

A team of rescue workers in California toiled for hours to free an unlikely victim -- a 16 million-year-old whale fossil trapped in a 1,000-pound rock in Rancho Palos Verdes, the Los Angeles Times reported Friday.

The ancient baleen whale fossil, which was originally discovered in 1978, was stuck in an incline on a hillside between two houses and will now be sent to the Natural History Museum of Los Angeles.

Baleen whales, 15 species of which exist even today, are characterized by the presence of a baleen -- a filter feeding system that allows the whales to ingest large quantities of fish at one time. As a result of its gluttonous dietary habits, baleen whales usually grow to extremely large sizes. The Blue whale, which is the largest known animal, is a baleen whale.

Only 20 fossils of baleen whales have ever been discovered.

“That tells you how rare it is,” Thomas said. “It is a very rare fossil and something that we actually go out looking for,” Howell Thomas, a senior paleontological preparator at the Natural History Museum, told the LA Times.

Gary Johnson, whose parents own one of the houses at the top of the hill, reportedly discovered the fossil at the base of the hill in 1978 and contacted a local museum. However, at the time, the museum found it logistically impossible to move the massive fossil.

Johnson contacted the Natural History Museum of Los Angeles in February this year after the organization unearthed another rare whale fossil on the other side of the hill.

After months of planning, the museum sent a 10-member volunteer crew to excavate the fossil on Friday. Using a system of straps, harnesses, pulleys and tripods typically used to lower rescuers into mine shafts, the crew hoisted the fossil to a backyard.

The fossil was then transported to the museum where researchers will now attempt to determine the whale’s species and the exact age of the fossil.