Ailanna Posted August 1, 2018 Share Posted August 1, 2018 I recently purchased this chunky ammonite from a Chinese seller on eBay. The seller said it was from Madagascar but provided no other information, and I haven't found any photos of Madagascar ammonites that look like this. The suture patterns are unusual (to my untrained eye), and the body chamber looks broken off rather than cut. Total length is about 6cm; width across the body chamber is about 3cm. There are currently several others like it available on eBay (search for 'raw jade ammonite'), some with more pronounced ribbing. Thanks! I appreciate any ideas you have about this one. Link to comment Share on other sites More sharing options...
PFOOLEY Posted August 7, 2018 Share Posted August 7, 2018 Cool Ammonite...compare with Desmoceras sp. 1 "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
Ailanna Posted August 7, 2018 Author Share Posted August 7, 2018 15 minutes ago, PFOOLEY said: Cool Ammonite...compare with Desmoceras sp. Thank you! I am looking at pictures of Desmoceras (I suspect some of the ones turning up on Google images are misidentified), and the shape/thickness look reasonable, but the sutures look quite different - the Desmoceras sutures that I'm seeing look a lot more...fingery? Angular? Sharply lobed like black oak leaves? I definitely don't have the right vocab to describe this! The sutures on mystery ammonite look smoother and curvier. Is that much variation with a genus common in ammonites? Link to comment Share on other sites More sharing options...
Bobby Rico Posted August 7, 2018 Share Posted August 7, 2018 I think Pfooley has it +1 for Desmoceras latidorsatum 1 Link to comment Share on other sites More sharing options...
FossilDAWG Posted August 7, 2018 Share Posted August 7, 2018 The sutures lose their sharp/angular features and become "smoother/curvier" when they are polished as this removed some material from the surface. This seems to be the case with your specimen. Unfortunately the loss of surface detail such as fine ribs and suture detail can make a definitive ID challenging. Don 1 Link to comment Share on other sites More sharing options...
Ailanna Posted August 7, 2018 Author Share Posted August 7, 2018 2 hours ago, FossilDAWG said: The sutures lose their sharp/angular features and become "smoother/curvier" when they are polished as this removed some material from the surface. This seems to be the case with your specimen. Unfortunately the loss of surface detail such as fine ribs and suture detail can make a definitive ID challenging. Don Good to know, thanks. That makes sense. 2 hours ago, Bobby Rico said: I think Pfooley has it +1 for Desmoceras latidorsatum Thanks! Consensus is a beautiful thing. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now