As all good SV-POW! regulars will know, Elmer S. Riggs published the name Brachiosaurus altothorax in a short (but not trival) 1903 paper (Riggs 1903) and followed it up with a proper descriptive monograph (Riggs 1904) that had several useful plates. I’ve never seen a real copy of the latter (or indeed the former), so for the last quarter-century I’ve made do with various low-quality photocopies and scans.

Now, finally, we have Riggs1904-brachiosaurus-altithorax–GOOD-SCAN! which you can download from https://svpow.wordpress.com/wp-content/uploads/2023/10/riggs1904-brachiosaurus-altithorax-good-scan.pdf or from a backup copy at http://www.miketaylor.org.uk/tmp/Riggs1904-brachiosaurus-altithorax–GOOD-SCAN.pdf — behold the beauty of Riggs’s plates as he intended them to look!

Lateral and posterior views of the first seven presacral vertebrae of Brachiosaurus atithorax (Riggs 1904:plate LXXII).

This scan comes to us courtesy of Katherine Olson at the University of Chicago Library. This is appropriate, as Brachiosaurus is very much a Chicago dinosaur. Many thanks indeed to Katherine!

Update (8 October 2023)

This lovely scan of this classic monograph is now also available on the Internet Archive, thanks to a Mastodon friend known to me only as “gay ornithopod”. (At least, it’s there until the organizations ironically known as “publishers” succeed in destroying the Internet Archive, as they are currently trying to do.)

References

• Riggs, Elmer S. (1903). Brachiosaurus altithorax, the largest
  known dinosaur. American Journal of Science 15(4):299-306.
• Riggs, Elmer S. 1904. Structure and relationships of opisthocoelian dinosaurs. Part II, the Brachiosauridae. Field Columbian Museum, Geological Series 2(6):229-247, plus plates LXXI-LXXV.

doi:10.59350/83sbj-tmq26