Since Herman Melville penned his novel Moby Dick more than 150 years ago , scientists have been fascinated by the remarkable attributes of the sperm whale and its kin - the smaller pygmy and dwarf whales . Now , fossils from an extinct pygmy sperm whale that died seven million years ago , have shed new light on the evolution of modern day whales . The remains , which were discovered in Panama , indicate that the organ involved in sound generation and echolocation got smaller throughout the whale ’ s evolution . Fossils from an extinct pygmy sperm whale that died seven million years ago have shed new light on the evolution of modern day whales . This image shows the right lateral view of the skull of Nanokogia isthmia . Although why this is so remains a mystery . While many whales , dolphins and porpoises have a long fossil record , enabling scientists to understand their evolution , there is limited evidence of sperm whales and smaller pygmy and dwarf whales , which are capable of navigating the ocean deep underwater . Now an international team of scientists , led by the Natural History Museum of Los Angeles County has discovered a new species of extinct pygmy sperm whale , called Nanokogia isthmia , which clarifies key aspects of the evolution of these animals . The well-preserved skulls of two individuals were unearthed at a sea cliff along the Caribbean coast of Panama . The find will help experts fill in gaps in the evolution of cetaceans . This is the evolutionary tree of sperm whales showing links between extinct and living species , and when the spermaceti organ changed shape . The remains , which were discovered in Panama , indicate that the bone involved in sound generation and echolocation got smaller throughout the evolution of the sperm whale . In contrast modern sperm whales ( a stock image is shown ) are much larger than their extinct relatives . The sperm whale is the largest of the toothed whales and the largest toothed predator . It 's only one of three living species in the sperm whale family , along with the pygmy sperm whale and dwarf sperm whale . Mature males reach an average length of 52 ft ( 16 metres ) with their head making up one third of their length . They mostly dine on squid and swim to depths of 7,380 FT ( 2,250 metres ) to hunt for prey . They are the second deepest diving mammal , following only Cuvier 's beaked whale . The sperm whale 's clicking vocalisation - a form of echolocation and communication - can be as loud as 230 decibels underwater , making it the loudest sound produced by any animal . It has the largest brain of any animal on Earth , more than five times heavier than a human 's and can live for more than 60 years . It reveals an unexpected level of complexity in the evolution of the spermaceti , which is an organ located within the head that plays a key role in the generation of sound and in the whale ’ s capacity for echolocation . The study , published in the journal Plos One , shows that at one time small sperm whales measuring around seven feet ( two metres in length ) had a much larger spermaceti organ relative to their size than modern day relatives . It got downsized at least twice during their evolutionary history , including the evolutionary event that gave origin to the living pygmy and dwarf sperm whales . Lead researcher Dr Jorge Velez-Juarbe said : ‘ The new discovery gives us a better understanding of the ancient distribution of these poorly known relatives of the sperm whale . ‘ Previously we knew of similarly-aged pygmy and dwarf whales from Baja California and Peru , but this new fossil fills in an important geographic gap in the group ’ s ancient distribution. ’ He added : 'Our study is part of a larger scientific effort aimed at understanding the changes in the marine habitats that resulted from the complete closure of the Isthmus of Panama , ' referring to the separation between the eastern Pacific Ocean and the Caribbean Sea that took place sometime within the last 10 million years . The new fossil is known from the well-preserved skulls of two individuals which were unearthed at a sea cliff along the Caribbean coast of Panama , shown on this map . The fossils show that at one time small sperm whales measuring around seven feet ( two metres in length ) had a much larger spermaceti organ relative to their size . A dorsal view of the fossilised skull is shown .
Team of scientists discovered new species of extinct pygmy sperm whale . Seven million-year-old Nanokogia isthmia bones were found in Panama . Suggest the bone involved in sound generation and echolocation got smaller throughout the whale ’ s evolution . seven million years ago 's larger sperm whales are able to navigate under water with ease .