|Ok...... I've been trying to figure something out concerning _Brachiosaurus altithorax_ , _Brachiosaurus brancai_ and _Giraffatitin brancai_..... Maybe Mr. Gregory S. Paul and Dino George can help me out . :-)
All right..... the type _Brachiosaurus altithorax_ was named in 1903 by Riggs and is from the western US. Janensch found and named _Brachiosaurus brancai_ from Tanzania in 1914. He knew it was a brachiosaur, but considered it distinct enough to be a separate species from _B. altithorax_. Now, in 1988, Paul takes another look at this and comes to the conclusion that _B. altithorax_ and _B. brancai_ were more distantly related...... So, we get _Giraffatitin brancai_ replacing _B. brancai_...... So now we have a subgenus of _Brachiosaurus_. Then, three years later, George Olshevsky elevates _Giraffatitin brancai_ to generic status, separating it from _Brachiosaurus_.
I can't find anything specific as to why this separation took place. What characters are so different in the two that warrants separate genus? The only thing I keep finding is that _Giraffatitin brancai_ has the highest arched nasals found in sauropods.... There has to be more to it than this. :-)
Also...... I'm guessing that _Giraffatitan brancai_ is the guy mounted in Berlin since it used to be _B. brancai_..... Is this guy also mounted outside the Chicago Field Museum???? And, is that _Brachiosaurus altithorax_ mounted at O'Hare Airport, or is that just _Giraffatitin brancai_ again??? Which is the largest mount?
I'm sorry if I botched something up........ this is just sooooooo confusing.....