VENTURA (CBSLA) — The fossil of an extinct species of sea cow has been discovered on one of the Channel Islands, according to the National Park Service.
The fossilized remains of a skull and partially articulated rib cage could be a previously unknown species of sea cow, an ancient relative of dugongs known as sirenians, parks spokeswoman Yvonne Menard said in a statement. The details are expected to be confirmed when it is analyzed by a Natural History Museum marine mammal taxonomic expert.
The fossil, estimated to be 20 to 25 million years old, could be one of the oldest of its kind on the west coast of North America. It was found in a steep ravine, exposed to the elements and erosion, as U.S. Geologic Survey scientists were mapping faults on Santa Rosa Island in July.
“This sea cow may have only been exposed the past few years after being buried for millions of years,” Paleontologist Dr. Jonathan Hoffman said in a statement. “It came from a different place and a different time period.”
Hoffman and a team from the Santa Barbara Museum of Natural History will protect the specimen during the upcoming winter and plan to excavate next spring or early summer.
Sea cows were believed to have lived in shallow seas millions of years ago, before the Pacific Plate migrated north and rotated, eventually bringing the ancient sea floor to its current position nearly 1,400 feet above sea level. The species had over a dozen different genera at one time and were named for the mermaids of Greek mythology. Their modern relatives include three manatee species and the dugong, which is found in the warm waters of the Pacific Ocean and the east coast of Africa.
The reason for sea cows extinction is unclear, but is believed to be linked to changes in food availability and changes in environment.
The fossil’s skull shape and features will be analyzed to identify its relationship to other sirenians. Park officials say the remnants of at least four other sea cow fossils were also found in the near vicinity.