Science can not fuse two completely different classes.
Archosauria and Amphibia/Reptilia are very similar, which is why it worked. Class Mammalia and Class Archosauria are worlds different despite being under the majority of land dwelling "chordata". Furthermore, ingelligence is not a genetic trait that you can claim was "fused"; the movies portray the animals as being likened to the intelligence of Whales and Primates.
I took an entire year for Zoological studies. Not even science can trump this. If it does, then Jurassic Park is no longer set in realistic sci-fi.