More importantly, these abilities haven't just increased, they've melded together in a unique way.
Well, that's not entirely accurate either. In any case, it's somewhat hard to explain.
Take the crocodile mutation for example. Originally, the little Sarcosuchus had dreadful running abilities. But now, even with its small, short legs, it can move quite quickly. It doesn't even resemble a crocodile anymore.
In other words, all the previous mutations had some shortcomings. For instance, some had poor night vision, while others were bad at running. But these weaknesses have significantly improved and aren't as noticeable anymore.
Consider the implications of such changes. Even something simply like Deinonychus, which originally couldn't dive, can now stay underwater for two hours without coming up for air.
Basically, these explanations are complex, but at the same time, pretty straightforward.
