Research detailing the fossil of a dwarf baleen whale, Herpetocetus, from Northern California reveals that it avoided extinction far longer than previously thought.
The 4-5 metre long whale, thought to be the last survivor of the primitive baleen whale family called cetotheres, may be as young as 700,000 years old.
The previously youngest-known fossils of this whale were from the pre-Ice Age Pliocene epoch; approximately 3 million years ago, a time before many modern marine mammals appeared. Baleen whales of this type were most common much earlier, about 10-15 million years ago.
This graphic shows the geologic ages of Herpetocetus and various well known marine and land mammals from California, with a life restoration of Herpetocetus.