In the history of the development of cetacean added an important, albeit controversial episode. Scientists were able to reach consensus on a fossil skeleton of an ancestor of dolphins, which lived 23 million years ago in oceans in the territory of modern South Carolina. They determined that it refers to a form Ankylorhiza tiedemani – the biggest, toothy and aggressive dolphins in the history of our planet.
The ancient skeleton of a Dolphin was found in the 1990s, but initially MIS-identified is not a coincidence. Dolphins Ankylorhiza tiedemani resembled modern species nothing more than an ancient Neanderthal and modern man. Huge, with a length of almost 5 m, with large teeth, they were on top of the food chain in the ocean of those distant times. Largely due to the fact that the first ever among the predators developed the ability of echolocation.
Today is the biological sonar have all kinds of dolphins, including killer whales, which occupy the top of the food chain among marine mammals. And 25 million years ago, on the border of extinction Ankylorhiza tiedemani, this property has allowed the dolphins to further distance themselves from the whale, and finally stop competing for food. Modern baleen whales feed on plankton, dolphins and fish, and allows them to coexist in one ecosystem.
And in the period 23-35 million years ago it was different. Scientists have noted with surprise that dolphins and whales independently from each other during the evolutionary process developed identical useful for life in the sea of features. For example, the structure of the caudal fin and the shape of the skull. This is important – they did not inherit these properties from a common ancestor, and got them on their own, trying to dominate the world ocean.
Source — Current Biology