Mammal Bone on UK beach

[SteppeJim]

Hi Everyone,

I went fossil hunting last weekend on the Norfolk coast, UK. A long walk up and down the beach of Happisburgh. Well known for its Ice Age mammal finds. I found a few different pieces, but this one in particular caught my eye. It's been rolled around in the surf somewhat, but I was hoping someone might be able to ID this for me? Because it does retain some shape still, it kind of looked like the end of a femur or tibia? But it does also resemble an ankle bone from a large animal, possibly Mammoth, Rhino or Bison? What do we think?

Thanks in Advance,

Jim.

Edited February 4 by SteppeJim

[Balance]

Excellent presentation of the item! 
 

I unfortunately can’t tell where it’s broken and been worn  vrs were it’s naturally shaped. My first thought was a pisiform or sesamoid type bone. Maybe look into patella/knee cap, and sesamoids of the species of larger size in your area. ?? 
 

Sorry not more help. 
 

Jp
 

Here’s a “rhino” patella that reminds me of yours.