ID help Peace River finds

[PODIGGER]

I have four specimens I found yesterday in the Peace River, FL that I need some help with on a positive ID.  First up is what I believe is a 4" fragment of a mammoth tooth with a long root?

 

 

Next up a nicely colored Bison upper molar?

 

 

I am hoping for an ID on the following Vert that I think is cetacean?

 

 

 

 

 

Finally, what I first thought to be a vert when pulled from the river.  I now have doubts due to the various indentations on the surface.  I am pretty confident it is bone but not sure what.

 

 

 

 

 

 

Looking forward to hear what others think!