Enchodus or Xiphactinus Fish

[Eddmon]

New to the group, so wanted to say hello. I'm looking for some help on this fish fossil. At first I thought for sure it was enchodus but in comparing it with one that I have it seems to have a much larger body unfortunately no head was found on this one. I realize that one could be  juvenile vs an adult with that being said these jaws if it is from this species are also different and larger then enchodus head that I have. Both or all were found within the same geologic area of each other along with mosasaurus vertebras. The jaw sections (8" and 6") in picture could be part of this species as they were found at the same location just not at the same SITE. Measurements: spine 24" long end of tail fin 16". Thank ED

 

[Fossildude19]

Welcome to the Forum.

 

I think we are going to need better, in focus, close up pictures.

Unless these were found side by side, I don't think you can assume they are associated.

More information on what country, region, state, county, or department found would be helpful as well.

Depending on where it was found, it could also be Pachyrhizodus, or Cimolichthys.

Cropped and brightened:

 

 

 

 

@oilshale  @Ptychodus04  @Uncle Siphuncle

[Ptychodus04]

The formation data is imperative, but judging from the tail shape and jaw shape/size, it looks a lot like Pachyrhizodus caninus.

[Eddmon]

Niobrara formation/ boarding marine shale formation (Kp, Qtg) , I'll work on some better pictures. Thanks

[Ptychodus04]

Pay special attention to the teeth when photographing the jaws. Cimolichthys has varied tooth size based on location (small  vs large depending on where they are). Pachyrhizodus has more evenly sized teeth. Not image below of P. caninus I collected several years ago.

 

[Eddmon]

[Ptychodus04]

It’s hard to be certain since the preservation isn’t stellar but the teeth look wrong for Pachyrhizodus. The distribution and variation in size make me lean towards Cimolichthys. 
 

I’m not an expert in fish though. I’ve seen quite a few from sites local to me but they are slightly older (Cenomanian and Turonian) and Cimolichthys isn’t known from them yet although it’s a possibility since several other Santonian genera are represented.