Axelorox Posted November 22, 2014 Share Posted November 22, 2014 (edited) I'm currently in the process of cataloging my whole collection, and am trying to get some (at least) general ids of all my unidentified specimens. I figure I'll start with some of the Madagascan ammonites I've bought over the years. Here are some I bought from Indiana9Fossils a few years ago. The only information the site had is that they are from the Cretaceous. And here are a few small whole ammonites. I'm not sure what period they're from. I'm thinking the first one is Cleoniceras sp. (if so what species?) A somewhat thicker whole ammonite - Desmoceras latidorsatum? Edited November 22, 2014 by Axelorox Link to comment Share on other sites More sharing options...
Vball Posted November 22, 2014 Share Posted November 22, 2014 (edited) Here are my guesses I found some ID's for mine after a lot of searching so here goes #1 Extinct Ammonite Cleoniceras cleon Albian Formation Tulear, Madagascar Early Cretaceous 100-112 Mil.Yrs #2 Extinct Ammonite Desmoceras latidorsatum Albian Formation Tulear, Madagascar Early Cretaceous 100-112 Mil.Yrs #3 Extinct Ammonite Desmoceras pseudouhligella Albian Formation Tulear, Madagascar Early Cretaceous 100-112 Mil.Yrs Those are the ones I have that look like yours but really only pretty sure about #1 the others could be something else. I guessed based on the pattern of the shell inside. Hope this helps Edited November 23, 2014 by Vball Link to comment Share on other sites More sharing options...
Axelorox Posted November 22, 2014 Author Share Posted November 22, 2014 Are you referring to the four whole ammonites? Link to comment Share on other sites More sharing options...
Vball Posted November 22, 2014 Share Posted November 22, 2014 No I started from the top with the split ones and the first whole one is #4 not sure on that one though it looks different than mine. Link to comment Share on other sites More sharing options...
Axelorox Posted November 22, 2014 Author Share Posted November 22, 2014 Ah ok, thanks for the guesses. I think you're most likely right on the first two. Can't find enough examples of D. pseudouhligella to comment on the third. The fourth one has me a bit confused; it seems close to Cleoniceras but not quite. What resources did you use in getting familiar with the various Madagascar ammonites? I haven't had much luck finding specific info on various genera and species online. Link to comment Share on other sites More sharing options...
Vball Posted November 22, 2014 Share Posted November 22, 2014 (edited) http://www.fossnet-fossils.com/ammomadagaskar.php I found this site not sure how accurate it is but it does have info at least. I might have to change some of my own ID's now EDIT if you click on the photos it will show all the different views which helps a bunch. Looks like your #4 is a Cleoniceras (Grycia) besairiei and the one I had in my collection as a Desocerus sp. is the Pseudosonneratia sakalava Edited November 23, 2014 by Vball Link to comment Share on other sites More sharing options...
Axelorox Posted November 23, 2014 Author Share Posted November 23, 2014 Thanks for the link. Going off of that site the first whole ammonite is Cleoniceras besairi and the last one is indeed Desmoceras latidorsatum. The first and third sliced ammonites look like more C. besairi while the 2nd looks like D. latidorsatum. Still not sure on the middle two whole ones. All I can tell is that the third whole one definitely isn't Cleoniceras. Anyone else have any experience with the site linked to earlier? Link to comment Share on other sites More sharing options...
Vball Posted November 23, 2014 Share Posted November 23, 2014 Ya sorry I couldn't be more help. I hope someone might enlighten us both. I found that a lot of the sites I found were just making stuff up for Id's so I had a hard time finding the Id's on mine too. Anyway good luck, Mike Link to comment Share on other sites More sharing options...
milou115 Posted November 23, 2014 Share Posted November 23, 2014 Hello ! In my opinion it is impossible to give an id of the splited ones with this view, show us the unpolished part... It is the same for the polished ones, you can get a precise id with the shell ! All the ways : All your ammonites look albian in age The first whole and unpolished one looks a Cleoniceras as you said, for the specie, you have two main species : C. besairiei and C. madagascariense, they vary in the costulation, C. madagascariense has a stronger costulation. In the present case I'll say C. besairiei The last whole and unpolished one looks has you said a Desmoceras latidorsatum The two polished ones looks Cleoniceras for the first one and Desmoceras for the second one ! Ventral views will be usefull ! Link to comment Share on other sites More sharing options...
Axelorox Posted November 24, 2014 Author Share Posted November 24, 2014 Thanks for the input. I will get up more pics of these specimens along with some others sometime this week. By now I think I have a good idea of what distinguishes Cleoniceras from Desmoceras, but it is distinguishing on the species level that seems to be difficult. Another question - do Madagascan ammonites of one genus/species tend to all come from one general locale, or are there many different possible locations where they could come from? Link to comment Share on other sites More sharing options...
milou115 Posted November 25, 2014 Share Posted November 25, 2014 There are different locations I think ! For exemple the Boeny, Atsimo-Andrefana region... Link to comment Share on other sites More sharing options...
Axelorox Posted November 28, 2014 Author Share Posted November 28, 2014 Okay, I went and took more photos of the the sliced pairs and the second and third whole ammonites from the OP. With the pairs I"m pretty sure 1 and 3 are Cleoniceras while 2 is Desmoceras, but I have no idea which species. Pair 1: Pair 2: Pair 3: OP whole ammonite #2: Pretty sure this is Cleoniceras but can't tell what species OP whole ammonite #3: Some Desmoceras species? I also have three more whole ammonites I'm unsure of: #1: Some species of Cleoniceras? #2: Some species of Desmoceras? #3: Not sure about this one Link to comment Share on other sites More sharing options...
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