Melbourne: A dwarf baleen whale from Northern California avoided extinction far longer than previously thought and well into Ice Age, researchers, detailing its fossil, have found.
Robert Boessenecker from the University of Otago`s Department of Geology, New Zealand found that the fossil of the 4-5 metre long Herpetocetus, thought to be the last survivor of the primitive baleen whale family called cetotheres, may be as young as 700,000 years old.
Boessenecker said 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.
"That this whale survived the great climatic and ecological upheavals of the Ice Age and almost into the modern era is very surprising as nearly all fossil marine mammals found after the end of the Pliocene appear identical to modern species.
"Other baleen whales underwent extreme body size increases in response to the new environment, but this dwarf whale must have still had a niche to inhabit which has only recently disappeared," Boessenecker said in a statement.
The finding indicates that the emergence of the modern marine mammals during the Ice Age may have happened more gradually than currently thought, he said.