I thought about a planet which was populated by Crustaceans, Molluscs and Fish as well as Odontocetes and Mysticetes as a result of a Wormhole event which existed from the Northeast Pacific to an ocean on a young, watery yet terrestrial Super-Earth which orbits two M-Type Stars where life hadn't developed before this event. The one way wormhole lasted roughly from 35-30 million years ago. The Cetacean life originate from a hybrid pod of Simocetus/Aetiocetus.