After the turmoil of end-of-year administrative duties, I'm now starting to turn my attention back to the Mastodons of Unusual Size Project.The subject of these week's Fossil Friday is a skull fragment that is being added to our dataset.The fragment is shown above in lateral view, with an annotated version below:
While most of the skull is missing, there is a substantial part of the left front preserved, including the socket for the left tusk, the upper left 2nd molar, and part of the bottom edge of the eye socket. Below is a partial ventral view (part of this side is hidden by the plaster jacket:
In this view it's clear that the 2nd molar is mostly intact. It's also quite heavily worn; this was a mature mastodon, probably almost as old as Max. It's 3rd molar should have been partially erupted, but that part of the skull is not preserved. The 2nd molar is 121 mm long, which is actually the longest M2 I've measured in a California specimen by a fairly large margin. But it's also only a little over 75 mm wide, making it unusually narrow even for a California specimen. The socket for the tusk is partially crushed, so I'm not confident about measurements of its diameter, but it seems on the small side; it's possible this is a female specimen.