Banner Day! Sea Urchin, shark, seal?

With the onset of winter, we've had a significant amount of rain recently, coupled with cooling temps. This weekend, we dropped down into the low 70s! (sorry, I couldn't resist). Anyways, after the 22 inches of rain we had 2 weeks ago, I figured the pickin's might be good, and I was right! There were the usual strombids, cowries, Neritas & such in abundance. I also managed another honker Cowrie (3.5"), 3 Turbos (rare because of their fragility) and a couple of gastropods I hadn't found before. I also picked up my second sea urchin! I really need to get a Hawaiian sea life guide to get the ID of these guys.. But best of all were the teeth: 4 Lemon Shark and one Seal!?! The seal(?) I spotted at eye level partially buried in the sediments, and I couldn't figure out what it was. When I plucked it out, I couldn't believe it! The tooth is clearly mammalian carnivore, and looks like a carnassial. I"ll post it in the ID section too to elicit input. It superficially resembles the seal teeth that I've found at LC, but without the surrounding rim at the base of the blade. I can't imagine what else it would be? Anyways, Aloha!