Furthermore , after the closure of the Central American Seaway , tropical whales decreased in diversity and abundance .
By the end of the Miocene , many species of mysticetes had gone extinct ; surviving species may have been faster swimmers and thus more elusive prey .
After the closure of the Central American Seaway , tropical whales decreased in diversity and abundance .
By the end of the Miocene , many species of mysticetes had gone extinct ; surviving species may have been faster swimmers and thus more elusive prey .