If I travelled back to the Oligocene Earth 33 Million Years Ago, brought some Oligocene Basal Mysticetes and Basal Odontocetes to LTT-1445 Ad with Squid, Krill, Fish and Plants then hybridised the Basal Mysticetes and Basal Odontocetes and left them there and travel forward to the Present of that timeline of LTT-1445 Ad... Could a new race of Semi-Aquatic Baleen Dolphins with four limbs evolve to contact Humanity... Could the bad aliens be defeated by them if the new species is gifted the right tech?

Just an idea of guiding the evolution of another group of Animals from another time.

i think shit would go all kinds of pear shaped