One of the fun parts of the job is that people find all sorts of things around Barrow. Often, they show them to me, or at least send me pictures. In a lot of cases I can ID them, but I’m not expert on extinct fauna, and the printed/online resources available are not as good as those for modern critters.
I usually send pictures to some folks at UAF (University of Alaska Fairbanks), since they actually have a pretty good collection. Unfortunately their current curator of mammals flatly denies any knowledge (!) of extinct animals, and doesn’t seem inclined to rural residents of the state that pays his salary by taking a peek in the collections to try to make an ID. So I’m broadening the search.
This particular tooth was given to the current owner. Matu believes it was found in a gravel operation near Barrow, AK. He’s really anxious to know what it is. If you have any ideas what it might be from, please let me know. If you have any colleagues who might be able to ID it, we’d appreciate it if you’d give them the URL for this post and ask them to take a look if they have time.
The following pictures aren’t great. I didn’t have a tripod or photo stand, or decent lighting. If you think you know what it might be, but need better pictures (not hard to imagine) or a particular angle, let me know and I’ll see if I can have him bring it to the lab for a better-lit portrait.
Out of Ice and Time 
Re bottom photo: could another animal have chewed on the tooth?