I've been looking at a lot of mastodons lately, so they're likely to show up more and more on Fossil Friday. Today's entry is an upper left 1st molar, collected from the West Dam at Diamond Valley Lake.The tooth is shown above in labial view (the side of the tooth on the outside of the mouth, literally closest to the lips), with anterior to the right. Of course, since it's an upper tooth, I really should have photographed it with the crown at the bottom.Here's the lingual side (literally, closest to the tongue):
Notice that the pointed parts of the crown (called lophs) are more worn in this view. In mastodons (and in many other mammals with grinding molars) the crowns of upper teeth will wear more rapidly on the more the labial side. The reverse is generally true of the lower teeth.Here's the occlusal view of the same tooth (with anterior toward the bottom):
While the labial side may be somewhat more worn, in this view we can see that there's heavy wear across the entire surface. Even so, had this mastodon lived longer, this tooth could have remained functional for quite some time. There roots are intact, and there's still a lot of enamel all the way around the margins of the tooth that had not yet worn away.