In three days scientists start arriving in Hemet for the Valley of the Mastodons symposium, and we're one week from the opening of the associated Valley of the Mastodons exhibit. As a result, I'm a little swamped, and today's Fossil Friday post will have to be brief.The original plan for Valley of the Mastodons was to display all of the mastodon material recovered from Diamond Valley Lake. That plan didn't last long. Our temporary exhibit gallery is 3,000 square feet, and while that's a pretty big room, we have a LOT of mastodons! It didn't take long to realize that they won't all fit. So we had to triage the collection, and things that have really cruddy preservation, and isolated bones that we can't say much about, are not going on display.One of the specimens that did make the cut is a partial mastodon from the West Dam, the area with the highest concentration of mastodons. This partial skeleton includes several ribs and vertebrae (a few weeks ago I featured its axis vertebra), a lower jaw fragment, a humerus, and both tusks. The tusks are shown above. They're reasonably well preserved, and include the open pulp cavities at the proximal ends (filled with sediment). The tips had crumbled a bit and are incomplete, but it doesn't look like too much is missing. The size of these tusks indicate that this was an adult male mastodon, although the unfused epiphyses on several vertebrae show that it wasn't quite finished growing.This mastodon and more than a dozen others will be on display beginning August 5 (WSC members are invited to a preview showing on August 4).