Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Portsmouth, UK) who mostly works on Cretaceous dinosaurs and pterosaurs. He also studies such things as the 
When most people (and that includes palaeontologists and dinosaur specialists) think of Brachiosaurus, they think of the east African taxon B. brancai, named by Werner Janensch in 1914. But they shouldn't: the 'real' Brachiosaurus is B. altithorax from the Morrison Formation of Colorado [later reported from Utah, Wyoming and Oklahoma], named by Elmer Riggs in 1903. The two species are actually quite different, leading Greg Paul to coin a new name - Giraffatitan - for the African taxon. This photo, kindly provided by Dr Matt Wedel (aka Dr Vector), shows the mounted B. altithorax skeleton that stands outside The Field Museum in Chicago. The little chap on the left is brachiosaurophile Mike P. Taylor. Mike's stuff on brachiosaurs, phylogenetic nomenclature and what-not can be downloaded from his website.
Comments
I've been to that museum many times, and stood beneath that massive beast at every opportunity. It really is an incredible mount, although, as you know, I'm not crazy about the giraffe neck. Great picture, though.
Posted by: Zach Miller | June 6, 2007 2:03 PM
Good point on the species. One minor note: Paul actually named Giraffatitan as a subgenus (one of the few in Mesozoic vertebrate paleontology). Olshevsky later raised it to the rank of genus. (As I recall anyway--just going off the top of my head here.)
Posted by: Mike Keesey | June 6, 2007 7:18 PM
Mike: I know - note the lack of the word genus in my text.. And what the hell is the point of a subgenus within a genus that only contains two species? Puh-leez. The good news is that a thorough analysis of the whole Brachiosaurus-Giraffatitan deal is currently in progress. I can say no more.
Posted by: Darren Naish | June 6, 2007 7:58 PM
What did they use for the head in the Field Museum mount? Looks like a knockoff of B. brancai.
Posted by: Nick Pharris | June 6, 2007 8:13 PM
Close. It's actually from this animal.
Posted by: Dr Vector | June 6, 2007 9:21 PM
What's really neat is to bring a little kid -- say four or five years old -- to see that skeleton and get them to stand right under it.
The expressions on their faces as they crane their necks upwards are priceless.
--RC
Posted by: Rick Cook | June 7, 2007 3:25 AM
Nick: yes, they will have used a B. brancai head for this cast. It's hard to get close enough to be sure :-) but I have some pretty good zoom photos, and it's definitely B. brancai. Actually, the mount is a pretty funny combination of things. It includes good quality casts of nearly all the B. altithorax type material (seven presacrals, sacrum, left coracoid, right humerus and femur) but the missing elements seem to have come from various places. The left femur seems to be cast from a specimen of B. brancai, the left humerus is a model not cast from any real element nor mirrored from the right humerus, and some other elements seem to have been mirrored. The tail is made up of pairs of identical caudals, presumably because it's cheaper to make two casts of a single caudal than single casts of two caudals! These, too, I assume are taken from a B. brancai specimen. The fourth dorsal is cast or modelled from D4 of the B. brancai cotype SII, and the remaining dorsals and all cervicals seem to be models, presumably based on those used in Janensch's B. brancai mount.
None of that should be interpreted as criticism, by the way: the mount is truly awesome -- all that it ought to be. And scientifically valuable, too, since it exposes surfaces that can't be seen in the actual B. altithorax type material, e.g. the anterior surface of the humerus which is face-down and can't be moved.
Posted by: Michael P. Taylor | June 7, 2007 10:10 AM
I wonder if...have a look at Jensen. Could that left humerus be a cast of the Potter Creek humerus? It looks just about right, and the Potter Creek humerus should have been out of the ground and cast in plenty of time to go into this mount.
Search your feelings. You know it to be true!
(Okay, it might not be true. But I'm having a hard time shaking it.)
Posted by: Dr Vector | June 7, 2007 12:35 PM
Matt: not a chance that the left humerus is cast from the Potter Creek specimen. It's heavily sculpted with lots of well-defined longitudial striations, especially near the distal end, and these are not preserved in the Potter Creek element (at least not if the figures in Jensen 1987 are to be trusted ... and even if they're not, I'd expect the figures to show _more_ reconstruction rather than less, given his track record with Supersaurus cervicals.)
Posted by: Michael P. Taylor | June 7, 2007 4:53 PM
There's also a nice mounted Brachiosaurus, provided by the Field, at O'Hare Airport in Chicago. It just seems to go up forever and it's *indoors*.
Bruce Townley
Posted by: Bruce Townley | June 7, 2007 5:13 PM