"Spinosaur" tooth, is it real & ID

[Trilobit]

I found this old tooth in a box in my house, the tip had snapped off. 

It said it was 'spinosaur tooth' 

Is it real, why does it have a strange pattern and if it is real, is it from some kind of spinosaur? 

[FB003]

Looks like a spino tooth to me.  Whether the tip originally belonged to it or not though, I can't say for sure.

[Bguild]

Real! Although I think the tip may be composited. There’s a repaired crack in the middle, but the two big halves appear to be part of the same tooth.

[Phos_01]

Yes its a real Spinosaurid tooth

[Sjfriend]

I am thinking same as @Bguild. I would want a close look at major crack to see if the two parts defects line up but it appears (to my non-pro eyes) to be just repaired not a full composite. Can't say about tip without a really good look.