Incredible...
I've seen all of the other ones in this series, and this is the first one that I've given a 10 to. It's not a perfect 10, mind you - there were a few places were the graphics were just a bit rough (during the middle of the battle scene, in particular), but overall this shows MANY signs of improvement from previous episodes. It's pretty damn close to a perfect 10. The graphics are smoother, the sound is quite nice and (for the second time) is pretty much perfect, and the story was fleshed out really nicely.
About the alligators - I guess the battle is between modern creatures and dinosaurs, then, not between lizards and mammals? I don't really know of another way to explain it.
I don't think that the little message at the end was quite right, though - it somehow ruined the serious mood. I think it should've been a little more "epic-sounding" than simply "these guys won this time".
I'm very curious right now about what the conclusion is going to be...
Oh, and I'm surprised at how few reviews this has gotten! This masterpiece deserves more attention, dammit! :P