Dolphins are not lucky enough to have the appendages required to develop tools.

As you said we have more "advanced" traits which at this time allows us to, for the most part, dominate the other members of the Animal kingdom.

We are not alone in our dominance over other species. In fact there are many species that have dominated other species. The extent of this dominace is irralvent to the topic (as I said man at this moment in time is most dominent) this dominance does not remove man from the animal kingdom.

Remember that the enviroment is not static and it is likly that at some point we will be the dominated species. If we were able to make our enviroment static then perhaps we would be seperated from the other memebers of the animal kingdoom.