RE #30
Is it possible that these T-Rex lived in the water just like crocodiles or hippos, partially submerged in the water. This way, water can support T-Rex's weight, and T-Rex can get around using less powerful legs. Is there any reason believe that T-Rex is only a dry land creature ?
That's a good question and in the particular case of the trex I couldn't rule it out on first principles. Some scientists still think sauropods lived in water since the square/cube problem is insurmountable, but that doesn't work for numerous reasons. A sauropod might get floatation in the center of a lake but there'd be nothing to eat there; he'd have to come to the edge of the lake to try to browse on vegetation growing there and, the first minute he did, his feet would go straight into the muddy lake bottom around the edge and he'd be stuck there for the rest of his life, which would be about two days starting from then.
Moreover, an adult elephant requires about 25 square miles of vegetation to eat on a yearly basis and a sauropod would require much more than that, and browsing around the edge of a lake wouldn't provide that kind of square mileage even if you forget about the problem with not having snowshoe feet.