Mammal Incisor (tusk, but not elaphantine)

[rkfrace]

Hello beloved forum.  I could use help on a mammal incisor ID for a friend: they don't have any info on the location, other than that it is domestic to the States, unfortunately.

 

I've ruled out Giant Beaver, and I assume it's not a baby mammoth tusk (there appears to be a slight 'bulge' in the middle). 

 

Any advice would be deeply appreciated.  Please see pictures.    

 

[ynot]

I am pretty sure it is a whale tooth.

@Boesse should know.

[Shellseeker]

1 hour ago, ynot said:

I am pretty sure it is a whale tooth.

@Boesse should know.

Ditto,

Here is a Florida whale tooth ... Horizontal Banding!!!!!

Your tooth,

 

These teeth are found in the SouthEast States,  If found in Florida , it would be called Kogiopsis .sp. What is the length of your tooth?

[rkfrace]

Thank you so much -- my friend was recently given the same advice.  In hindsight, it seems so obvious (I have two Kogiopsis of my own, though they are mineralized pure black).  I really appreciate your time and assistance Shellseeker.

[Boesse]

I just saw this on facebook someplace - certainly a sperm whale tooth.