Duck Creek Formation ammonite ID

[KimTexan]

I found this ammonite yesterday in what I believe was the Duck Creek Formation in Grayson county, Texas. I think it looks a bit like the Oxytropidoceras, but I didn’t realize they were found in that formation. Can anyone give me a little direction on ID of it?

I haven’t taken other shots yet, but it is very thin for how large it is. Maybe an inch thick. I’ll measure it tomorrow, but it’s at least 10 inches in diameter. I’ll post more shots tomorrow. The other side has a nice view of the sutures.

[Nimravis]

Nice find Kim- Congrats.

 

@Ludwigia

[John S.]

Awesome

[Ludwigia]

@Uncle Siphuncle

[Uncle Siphuncle]

Oxy, either extremely basal Duck Creek or underlying Kiamichi.

[Heteromorph]

Nice ammonite! Perhaps geologic compression is to blame for how thin it is.

[Ptychodus04]

2 minutes ago, Heteromorph said:

Nice ammonite! Perhaps geologic compression is to blame for how thin it is.

 

There may be some compression but Oxys are extremely thin as compared to other ammonites. Thin profile and a sharp keel, these guys must have been able to scream through the water.

[KimTexan]

I don’t think there was much compression going on compared to normal. I think there were at least 5 species of ammonites there, possibly 6 or 7. I’m not sure I’ve seen so many species in one small area. The Oxy was the least common.

I found fragments of at least 2 species of heteromorphs there. I still need to ID them too. There were only 2 other genus there that I have seen and found before. All the others were new to me. Gotta start learning to ID them better. This was a good opportunity to learn 5 other genus.

Ok here are more pics. The pic I took of the keel before I left home this AM is not sharp. I’ll take another this evening.

Here is the other side where you can see sutures.

 

This is what I believe is heteromorph I found there. I found another next to it that is a smaller fragment which actually had a spot of ammolite on it. I was ecstatic to see that. I’ve never found an ammonite with that on it.

 

Here is the other type of heteromorph. There are 2 examples of it. One is encrusted with oysters.

If anyone can help ID these 2 I’d appreciate it.

[Heteromorph]

I can’t help with the first heteromorph but I am pretty sure the last 2 are both of the genus Idiohamites. Here are some from around Lake Texoma:

Idiohamites

 

EDIT: More Duck Creek Idiohamites for good measure: 

Ammonites - Spring Creek, Cooke Co., TX

 

[JohnBrewer]

12 hours ago, KimTexan said:

I found this ammonite yesterday in what I believe was the Duck Creek Formation in Grayson county, Texas. I think it looks a bit like the Oxytropidoceras, but I didn’t realize they were found in that formation. Can anyone give me a little direction on ID of it?

I haven’t taken other shots yet, but it is very thin for how large it is. Maybe an inch thick. I’ll measure it tomorrow, but it’s at least 10 inches in diameter. I’ll post more shots tomorrow. The other side has a nice view of the sutures.

That must weigh some Kim and your holding it with one hand! Nice find. 

[Heteromorph]

I am probably wrong but the first one doesn’t really look like a heteromorph to me. It looks like it was a very evolute normal ammonite. When I look at the dorsum I see where the previous whorl came into contact with it.

 

EDIT: Perhaps a species of Mortoniceras? Here are some from the Duck Creek:

Ammonites - Spring Creek, Cooke Co., TX

 

 

[Bobby Rico]

13 hours ago, KimTexan said:

 

Fantastic find Kim . You must be very pleased .

[GeschWhat]

Wow - Nice!

[Tidgy's Dad]

Lovely finds, Kim! 

That first ammonite is a beauty. 

[Uncle Siphuncle]

Still thinking basal Kdc/upper Kki. This was a transition zone where Oxys were replaced by Morts, with Craginites and Adkinsites making the scene in that short transition, with Idiohamites present along with that honkin’ big heteromorph, whose name escapes me.  Spatangoids sparse but present in this zone.

[KimTexan]

3 hours ago, JohnBrewer said:

That must weigh some Kim and your holding it with one hand! Nice find. 

Thanks John, it is quite thin. I doubt if it weighs over 5 lbs.  

[KimTexan]

Ok here is what I guess you’d call the venteral adoral view of the Oxy. 

Below is one with the caliper. The tips aren’t quite long enough to reach to the widest whirl so the pic is with it on a narrower whorl and is reading about 32 mm, but is short of reaching the thickest part. Near the aperture it is about 50 mm. The diameter is about 268 mm.

I was trying to narrow down what species it is. I think I have settled upon Oxytropidoceras elaboratum elaboratum. I’d be happy to hear any other opinions or thoughts.

 

Edited March 6, 2018 by KimTexan
Forgot to add the 2nd elaboratum.

[Nimravis]

@KimTexan from the above pic, it looks like you are going to need more room around the fireplace.

[KimTexan]

Yes, I have those and a number more. I need a better way to display them and I am sure they need some prepping. I need to find someone who can give me a few pointers on prep though.  

I think I have only identified maybe 1/3 of the whole ones I have. I have quite a few fragments of other species that I’ve never ID’d either. I picked them up because I knew I didn’t have them represented in my collection.

I just got a Texas ammonite book a week or so ago and I’m starting to attempt to identify my ammonites. I have a lot of them that are rather non-descript that will probably be a bit more challenging to ID. This Oxy was pretty distinctive and easier to ID.

I also have accumulated numerous one that are still stuck in rock hard matrix.

 

I use to want one of those big Eopachydiscus, but after hauling out 40+ pounds of fossils on so many trips down creeks, I’m thinking hauling one of those out is probably more than I can handle. I’m always looking for more species I don’t have and better examples of the ones I do have though.

[amon81]

Magnificient