Ammonite ID (central texas)

[Jared C]

Hey y'all, here's an ammonite I found in what I'm fairly sure is a small, unmapped Eagle Ford outcrop. I'm hoping to use it as an index fossil, as the target species that I'm hoping this outcrop will produce occurs in the late cenomanian/early turonian Bouldin Flags member of the Eagle Ford formation.

 

I find that the written descriptions that I've read about the bouldin flags geology are inadequate for my understanding, as it seems colors, shades, and degree of textures are up to the interpretation of the reader. Maybe I'm just overthinking that though. Hopefully this ammo helps.

 

@LSCHNELLE, I know you're familiar with the Bouldin Flags - seem familiar?

(Diameter=1 inch)

 

 

 

[JohnJ]

Compare to Prionocyclus.

[LSCHNELLE]

I'm not much of an ammonite zone expert.  If JohnJ is right (I think that he is), then your ammonite is from the Upper Turonian - South Bosque Member of the Eagle Ford.

 

You will need to look for Acanthoceras ammonites as a marker fossil for the Bouldin Flags member.

 

Attached pics are a two of many that I have found in the Bouldin Flags member. I think that these two are Acanthoceras sp.