I'm probably the odd man out here. While I agree that animals and humans have some qualities in common and I don't know what they are exactly, nor would I speak so confidently. People who speak too confidently, in my opinion, have too much faith.
With that said, there are marked differences. Let me give a few examples. One of the things that I have been studying for the past few months is the history of laughter and it occurred to me that this might be a distinct human quality. We find things funny and we tell jokes. Do animals? I am not sure. Also when we are confronted with something awesome and beyond us, like pictures of the universe, we are filled with wonder. Do animal wonder at the beauty of a sun set? Probably not.
One final example. I am also studying the difference between envy and covetousness in the ancient world. It is a fine distinction, but again do animal covet and envy? Probably not. The previous answers speak of continuity, I like to talk the about discontinuity. It is a matter of perspective.