Why is the whale shark considered a mammal?

Unlike whales, sharks are not mammals but belong to a group of cartilaginous fishes. The whale shark (Rhinodon typus) earns the name “whale” solely because of its size. read more

Whales are mammals and sharks are fishes. But the whale shark is a fish. It is understandable that certain traits leads to the assumption that whale sharks are mammals, nonetheless the distinguishing visible trait that differs these similarly looking creatures as fishes or mammals is the breathing method, means of birth, and, most notably, the tail. read more

In fact, live offspring are neither restricted to mammals, nor are all mammals livebearers. A characteristic shared by all members of a group because of their common descent is called a synapomorphy. Live young is not a synapomorphy of mammalia. Mammaries are. Lots of fish, reptiles, and mammals give birth to live young. read more

In fact the blue whale is the largest living mammal (and animal species) on this earth. In terms of size the blue whale can grow to lengths of over 90 ft. long and weigh more than 150 tons. As a comparison to the blue whale the smallest known mammal in the world is the bumblebee bat which measures in at 1 – 1.5 inches long and weighs a mere 2 grams. read more