San Antonio Texas Ammonites Species ID Help

[willtexas07]

I have found several ammonites in walking around local creeks. Best guess on the formation is Georgetown. Most are creek worn and species identification may not be possible. Any help would be greatly appreciated.

[willtexas07]

Last one.

[JohnJ]

In addition to sutures, ribs, geometry and ornamentation, keel views are useful in assisting a general ID.

[BobWill]

In addition to sutures, ribs, geometry and ornamentation, keel views are useful in assisting a general ID.

Nice variety of ammonites. If you can show the edge view try to include a view of the whorl profile by showing the aperture since some ammonites descriptions include a ratio of the height of the whorl to the width. The shape of the keel can also be diagnostic if present and if not it helps to know whether any ribs continue around the venter.

[willtexas07]

Thanks John and Bob. I will get some edge shots up in the morning. I should have realized they would be needed for ID.

[willtexas07]

BobWIll I bet you have some very neat finds based on your being from Cooke County,

[BobWill]

Lots of ammonites here plus it puts me close to sites in Ok and my personal favorite, Jacksboro.

[Uncle Siphuncle]

Will

That's a pretty good assemblage of ammos for this area, where they are not very commonly found in the Albian. Interesting how the last one is quite a bit more evolute than the others. A couple (3 and 4) look like they could pre-date Mortoniceras, maybe something in the Adkinsites spectrum. The fifth one throws me off a bit with its widely spaced, sinuous ribs lacking tubercles. You might consider bringing them over to my house sometime to compare with North Texas specimens. I probably live with 5-10 miles of you. Don't worry about me pumping you for sites...I have plenty of my own to keep me busy. Feel free to PM me if interested.

[BobWill]

Yeah Dan, I noticed the same features and It's hard to tell if the 2nd one even has a keel. Quite a variety for any site especially if they are less common in that area.

Will, more pictures might help, but you can't beat a hands-on look by someone like Dan. His experience in that area (and many others) would give you the most accurate identification and the chance to see some of his fossils is something we would all appreciate.

[Uncle Siphuncle]

For what I can't answer, I have a friend I can ask. He researches ammonites of that age worldwide.

[doushantuo]

And his name is Bill?

[CraigHyatt]

And his name is Bill?

His name is Frank. Only I can see him. ;-)

[doushantuo]

I suddenly hear 80's music from somewhere.....

Edited June 23, 2016 by doushantuo