What is it Steemians?

I found it on the beach yesterday morning after deciding to check it out given the incredible wet and windy stormy weather the last few days. It is the most unusual shape, texture and smells fishy. It is softish, whole and looks like a tooth.
I asked a man who worked on fishing trawlers for a living, he did not know.
I asked the surf lifeguard hiding away in the tower out of the rain. She did not know.

I took it home to ask my husband, he did not know.
I thought maybe someone who has a lot of experience photographing sea animals might know. Can you help ?

I put it into a little bucket in the garage last night just in case it exploded or some animal hatched from it. Just kidding!
Cheers