[oldcats]

Gladly....
As you might imagine, larger animals have larger brains. However, this does not mean that animals with larger brains are smarter than animals with smaller brains. For example, a larger brain is necessary to control larger muscles in larger animals and a larger brain is necessary to process more sensory information from the skin in larger animals - this has nothing to do with intelligence.
My Brain is Bigger than Your Brain
A rather simplistic explaination, but it's a start.
Oldcats

[gore3000]

It certainly backs up your statement somewhat. It also has a lot of interesting information on the brain, wish it had more. However, even here there are problems with the statement. For example whales are said to be smarter than elephants yet they have a slightly smaller brain than elephants and a larger body size. While the article gives the brain weights of numerous animals, it only gives the percentage to body size of a few. It says that in larger animals more of the brain is needed for skin sensations and muscular control, but I wonder how much that would account for. Also we have the problem of intelligence in humans. We know that brain size in humans does not differ according to intelligence. Why should it matter when we are speaking of different species then?

As to evolution and paleontology specifically there are some problems using brain size. First of all, the size of the skull does not necessarily tell us close enough the size of the brain. Neanderthal had a larger skull than homo sapiens, yet we know it was not as smart. The article says that the folds of the cerebral cortex are important as to the brain's capapbilities. Bones cannot answer that question.