Premise: Baleen whales ( systematic name Mysticeti ) , known earlier as whalebone whales , form a parvorder of the infraorder Cetacea ( whales , dolphins and porpoises ) . The blue whale ( Balaenoptera musculus ) is a marine mammal belonging to the baleen whales ( Mysticeti ) . At up to 29.9 m in length and with a maximum recorded weight of 173 tonne and probably reaching over 181 tonnes ( 200 short tons ) , it is the largest animal known to have ever existed .
Hypothesis: The blue whale is a whale.
Label: ENTAILMENT