The Geologic Ages of the Dwarf Baleen Whale Herpetocetus (image) University of Otago Share Print E-Mail Caption 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. Credit R.W. Boessenecker Usage Restrictions With credit to R.W. Boessenecker Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.