Scientists say they found the fossil remains of a sea cow that lived off California's Channel Islands almost 25 million years ago.
The National Park Service says the skull and rib cage was discovered last summer on Santa Rosa Island.
Experts say it is most likely the remains from a previously unknown sea cow species, but can't know for sure until further analysis.
Sea cows live in shallow waters, can grow up to 13 feet long and the only living species left are the dugong and three types of manatee.
Jonathan Hoffman with the Santa Barbara Museum of Natural History says it seemed erosion is what have may have finally revealed the bones.
"This sea cow may have only been exposed the past few years after being buried for millions of years."