Ammonite ID

[Dord]

I found this fossil kind of out of place at a hobby store and the only identification it had was "Madagascar Ammonite". I know it's no fun that I bought it and didn't dig it up myself but any further information on what kind of ammonite it was and when it lived would be much appreciated. I tried to be as detailed as possible in the picture to make up for the lack of info. Also, what's up with the iridescence? Is it special?

[Kane]

Nice acquisition. Although I cannot help with an identification, we do have some information on the iridescent question in this thread, with some key helpful information provided by @piranha: 

 

[Ludwigia]

27 minutes ago, Dord said:

I found this fossil kind of out of place at a hobby store and the only identification it had was "Madagascar Ammonite". I know it's no fun that I bought it and didn't dig it up myself but any further information on what kind of ammonite it was and when it lived would be much appreciated. I tried to be as detailed as possible in the picture to make up for the lack of info. Also, what's up with the iridescence? Is it special?

Thanks for the excellent photos. That looks to me like a Cleoniceras besairei  from the Cretaceous Albian stage, perhaps from Maharanga.

 

[abyssunder]

This excerpt I made, from M. Collignon. 1963. Atlas des fossiles caracteristiques de Madagascar (Ammonites). Fascicule X (Albien). Service Geologique Tananarive, might be helpful.

Cleoniceras.pdf

 

[RJB]

I was going to say Cleoniceras but Ludwigia beat me to it.  He is much better than I at the ammo's and has givin some extra good info too that I would not have known. 

 

RB