US palaeontologists studying fossils recovered from the San Diego Formation in California have described a new species of baleen whale that would have lived between 3.5 and 2.5 million years ago.
Until now, the genus Herpetocetus (a genus of now extinct dwarf baleen whales) contained four recognised species, this new specimen – known as Herpetocetus morrowi – brings that total to five.
The researchers believe that H. morrowi was one of the smallest baleen whales, measuring only 4.5m in length. They also postulate that it could have been a bottom-feeder, feeding in a similar way as the gray whale, where they are known to roll on to one side (usually the right side in gray whales – hence why sometimes the baleen on the right side is shorter and the head more scarred) and then swim slowly along the bottom sucking up the sediment before filtering it out through their baleen and trapping their food behind.
Compared to the finding that dolphins have been around for between 8 and 13 million years this is not quite as ground-breaking but interesting nonetheless as it gives more insight into the evolutionary changes that have taken, and undoubtedly continue to take place, within whales, dolphins and porpoises.