The pygmy right whale is a small baleen whale found exclusively in waters of the Southern Ocean. Because it does not frequent shallow water and is of a size of no commercial value, it is little studied. It was first documented based on bones and baleen plates found during the 1839-1843 exploratory voyage of the HMS Erebus and the HMS Terror. Due to its resemblance to the right whale, it was named the pygmy right whale (Balaena marginata). Further study resulted in it being placed in a new genus (Caperea), but the popular name remained unchanged. The scientific name refers to the wrinkled appearance of the ear bone and to the dark border around the baleen plates of some individuals. It is by far the smallest of the baleen whales, with adults having a length of about 20 feet and a weight of about 6,700 pounds. Unlike true right whales, the pygmy right whale lacks callosities. Its blow is also small and indistinct. The population is unknown. Recent studies have led researchers to conclude that the pygmy right whale is the actually last living species of a family of whales known as cetotheres (scientific name – Neobalaenidae) previously thought to have gone extinct over two million years ago. The cetotheres branched off from the other baleen whales about 15 million years ago. Their fossils are found in all the world’s oceans. Much remains to be learned about these sole survivors.