Nautiloid Cephalopod?

[keldeo072]

Found in a creek East Fork Lake in Cincinnati. 14 centimeters in length. It looked to me like a nautiloid because of its shape but it doesn't have any of the distinctive markings like a nautiloid does. Someone suggested that it could be a cast. You can see the imprint of the rest of the fossil.

 

 

 

 

What it looks like now after I broke the rest of the rock apart

 

Opening of the cone shape, looks like a brachiopod?

 

Nautiloid Cephalopod markings I'm talking about:

[Darktooth]

It is a cephalopod. They don't always show the chamber lines.

[Innocentx]

2 hours ago, keldeo072 said:

Opening of the cone shape, looks like a brachiopod?

I think the brach just ended up in the cavity like the other smaller pieces of shell and etc., by wave action.

I agree with cephalopod.