Featured Image Credit: C. M. Peredo et al., 2018/Current Biology
Have you ever wondered why large whales have baleen instead of teeth? Although some whales (like killer whales) have teeth, many of the larger whales (like blue whales) have baleen plates instead. The plates act like a filter to allow these large whales to feed on small prey like krill. With these structures, the largest mammals in the world can eat tons of food everyday and not even stop to chew!
The structure of baleen is actually composed of flexible hair-like plates. With these structures, the whales just filter their food. However, the evolution of baleen was unclear until now. Scientists have wondered how the whales made the evolutionary jumps from teeth to baleen plates.
Smithsonian scientists recently uncovered the link! In the fossil record there is a whale that had neither baleen plates or teeth. The whale, Maiabalaena nesbittae, lived approximately 33 million years ago. The whale was roughly 15 feet long. Carlos Mauricio Peredo, the lead author on the study, had this to say, “A living baleen whale has a big, broad roof in its mouth, and it’s also thickened to create attachment sites for the baleen. Maiabalaena does not. We can pretty conclusively tell you this fossil species didn’t have teeth, and it is more likely than not that it didn’t have baleen either.”
Scientists believe that this whale could neither chew or filter feed. It appears to have a strong cheek and retractable tongue that could suck in water (and food) into its mouth. This is huge piece of evolutionary history. Without this whale, baleen whales as we know them today may not exist.
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