Triceratops Brow Horn or Ankylosaur Spike Dinosaur or ...?

[emc2]

I purchased it from eBay. It's from the Lance Formation of Eastern, WY.

The exterior surface of the bone is pitted and has grooves just like a Triceratops brow horn.  However, all of the Triceratops horns I have seen are conical, meaning they are round in cross section which this fossil is not.  The cross section looks more triangular or diamond-like.  This fossil has no compression or cracks in it which leads me to believe that the true cross section is more triangular or diamond-like than round in shape.  The only other horns/spikes that would have surface bone texture like this and have that shape would be a large Ankylosaur side/shoulder spike.  The fossil is partial so I cannot make a 100% definite ID either way so it is possibly a strangely shaped Triceratops brow horn section or a partial Ankylosaur side spike.  

 

[hxmendoza]

Its the end of a brow horn. We have quite a few being worked on in the prep lab here at the museum. I've seen the triangular cross-section as well as round and ovoid, towards the tip.

[emc2]

I don't find any information on internet about it .

Could you give me some information about it.

On 2017/8/4 at 5:34 PM, hxmendoza said:

Its the end of a brow horn. We have quite a few being worked on in the prep lab here at the museum. I've seen the triangular cross-section as well as round and ovoid, towards the tip.

I don't find any information on internet about it .

Could you give me some information about it.

[jpc]

hxmendosa's info is form personal experience, as is mine.  I also see a ceratopsian brow horn.  The concavity at the base is also not like an ankylosaur spike.  I would say it is closer to the base than the tip.  

[The Speeding Carno]

13 hours ago, emc2 said:

I don't find any information on internet about it .

Could you give me some information about it.

I don't find any information on internet about it .

Could you give me some information about it.

Maybe look for pictures of other triceratops brow horns and compare them to ankylosaur scutes

[Troodon]

I agree with the others it's a Ceratopsian brow horn.  I have seen a number that are compressed like yours.