WHALE FAMILY TREE ART POSTER

It’s hard to imagine a whale as a gigantic, legless, air-breathing, ocean going cousin to a hippopotamus, but scientific analysis tells us it’s true. Whales are not descended from hippos but rather they share a common ancestor with them. So yes, they’re “kin” to each other. Pretty wild, eh?

The link between them is a group of animals known as the Anthracotheres that gave rise to the Ambulocetids, or “walking whales” 50 million years ago. Since the early 1990’s extraordinary fossils of these weird looking transitional animals have been found in Pakistan and India. Whales diversified rapidly over the next 15 million years. Their front limbs evolved into fins and their hind limbs eventually disappeared altogether although small pelvic bones can still be found in living whales.

There are about 80 species of whales, or cetaceans alive today. They can be classified into two basic groups: the toothed whales (Odontocetes) and the baleen or filter-feeding whales (Mysticetes). There are about 65 species of toothed whales, including dolphins and porpoises. They have one blowhole while baleen whales have two. Toothed whales tend to be smaller than their baleen cousins, although the Sperm whale can grow to 60 ft.

Baleen whales are probably the largest animals to ever live on the Earth. The biggest Blue Whales can grow to 110 feet and weigh 180 tons. That’s a whole lotta’ whale! Baleen whales are named after the large hair-like plates that hang from their gums from both sides of their upper jaws. They use the baleen to strain food from the water that they take into their mouths.

The split between the toothed whales and baleen whales occurred around 17 to 26 million years ago. Extinct whales like Mammalodon and Aetiocetus show characteristics from both groups. As more fossils are found along the ancient coastlines of the world more clues will tell us more about these fascinating creatures and how they came to be.