Very Old Bone knife handle - Conservation and info help needed

[Flintlockandsteel]

Couldn't think where to post this one so hope it's ok here.

The dog just dug this out of my ex wife's garden.
I'm hoping someone here might be able to offer age and identification info on it.
I'm also a member of British Blades forum but have never been able to post there - no idea why I can't. Nearly given up on that one.

Anyway here it is ...

Weird way of posting images

 

[Mesquite]

Have you any pics of the blade as well as any measurements to give a sense of scale?

 

[Flintlockandsteel]

There is no blade only what looks to be a roundish stub sticking out of the handle. Could it be a fork?
I have another picture to post but the computer's been playing silly sods tonight.
My feeling is 17th / 18th century but not sure.
Was hoping someone might recognise the style.
Will see if I can get a better set of what's left tomorow with better light.
Importantly as it dries out I can see this deteriorating. I could do with info on conservation.