I have no idea what it is. It doesn't look like any of the above though. Logging tools like pikes and peaveys should have sharper points. Rail lifters with a pole and yoke I think would be more rigid. It almost looks like a big two jaw gear puller but not quite unless it's missing something.It's interesting but not enough for me to want it.Sorry.
The more I look at this the more perplexed I am, the center handle doesn't appear to be there for much more than lifting or carrying it, the jaws only swivel from the point of their bolts and can't do anything more or be adjusted in any way. The three holes don't seem functional because it appears if anything was inserted in them you couldn't use the pivoting handle, and as for the "base" piece I can only assume it was bolted to something thru the two holes in it. Time for some research....
That didn't take as long as I thought it would, and once again I bow down to Pat and the knowledge he has stored in that head of his, Kudos Pat!!! This is a fence puller(wire stretcher) as Pat stated, here are two drawings from the 1898 patent for the device, it operates in a very simple manner as you can see.