The blue whale ("Balaenoptera musculus") is a marine mammal of the suborder of baleen whales (called Mysticeti). They grow to be about 30 meters long. The biggest blue whale found was 190 tons and measured 98 feet long. Larger specimens have been measured at 110 feet, but never weighed. This makes blue whales the largest animals ever to be on Earth, even bigger than the largest dinosaurs.