4 ms·

True. And all land vertebrates are technically fish.

• whyenot 8mo ago
  They share a common ancestor with ancient fish, yes. Land mammals also share a common ancestor with starfish. That doesn't make them starfish.
  • eesmith 8mo ago
    The "humans are fish" idea comes from cladistics. "Fish", if taken as a monophyletic term, includes land mammals because tetrapods are osteichthyans -- bony fish. In common use, "fish" is, however a paraphyletic group which excludes tetrapods but otherwise includes all other osteichthyans. Since starfishes don't include tetrapods, nor vice versa (nor do they share biological features to be in a polyphyletic grouping like "crabs"), the relevant common term is "Animalia" -- "animal".