14 DAY TRIAL // Baleen whales form a group of marine animals that includes the largest living thing on the planet, the blue whale. They do not feed like other creatures, by swallowing or chewing their food, but by filtering enormous amounts of water using their baleens. These structures that they have on their upper jaws allow them to filter seafood from seawater, and to collect impressive amounts of nutrients each day. Now, marine biologists and anthropologists believe they may have finally discovered the elusive origins of the beast, LiveScience reports.
After analyzing a peculiar, extinct dwarf whale, researchers have concluded that the origins of the baleen whales may rest inside the mud on the sea and ocean floors. The experts believe that the impressively large creatures might have acted just like vacuum cleaners, sucking in and filtering the mud in search of any food that was unlucky enough to be there at the time. In order to get to these conclusions, the scientists analyzed a ten-foot-long whale fossil, discovered off Torquay, a coastal town in southeast Australia.
The specimen was an early, dwarf whale called Mammalodon colliveri that lived more than 25 million years ago. The goal of the research was to determine how these whales appeared from the small creatures that populated the world's oceans before. “The seas off southern Australia were a cradle for the evolution of a variety of tiny, weird whales that seem to have lived nowhere else,” Museum Victoria in Australia paleobiologist and researcher Erich Fitzgerald explains. The old whale was smaller, more round than existing varieties, and lived in shallow, warm waters next to corals, invertebrates, sea urchins, and sharks so big that they put the Great White to shame.
The hints that gave away the fact that it fed on the bottom of the sea were the reduced front teeth, the short and blunt snout, and the highly developed lip muscles. In addition, the wear signs on the fossil's teeth seem to suggest that they were constantly battered with sand, which is consistent with the bottom-feeding hypothesis. “You see features like this in beluga whales. They use their tongue and lip muscles to suck prey off the seafloor,” Fitzgerald explains. “Sucking prey from a sandy, muddy bottom makes sense to me as a simpler evolutionary step, going from filtering food using teeth to filter feeding out of the water. Charles Darwin made that same speculation in 'On the Origin of Species',” he adds.