Douvilleiceras Posted September 24, 2017 Share Posted September 24, 2017 Hello All, Recently, I've acquired a sliced half of the Cretaceous heteromorph ammonite Scaphites. While rarely sliced, I managed to find one buried in a pile of similarly sliced Madagascar ammonites, and purchased it. Here are the photos: 1. A view of the whole ammonite. Here, we can see the phragmocone as well as the sediment-filled living chamber. 2. A closeup of the phragmocone, showing the beautiful septa. The minerals are very pure in this example, making some chambers appear as if they are filled with a tinted glass. 3. The point of no return: the outer whorl splits off from its counterpart, creating the unique shape which Scaphites and its relatives are known for. Regards, Jason "Trilobites survived for a total of three hundred million years, almost the whole duration of the Palaeozoic era: who are we johnny-come-latelies to label them as either ‘primitive’ or ‘unsuccessful’? Men have so far survived half a per cent as long." - Richard Fortey, Trilobite: Eyewitness to Evolution. Link to comment Share on other sites More sharing options...
ynot Posted September 24, 2017 Share Posted September 24, 2017 Interesting! Thanks for sharing. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
caterpillar Posted September 25, 2017 Share Posted September 25, 2017 May we see the other side please? http://www.paleotheque.fr Link to comment Share on other sites More sharing options...
Douvilleiceras Posted September 26, 2017 Author Share Posted September 26, 2017 13 hours ago, caterpillar said: May we see the other side please? Sure! Here's the other side! It appears that it did not get much preparation, but the fine details are still exposed. Regards, Jason "Trilobites survived for a total of three hundred million years, almost the whole duration of the Palaeozoic era: who are we johnny-come-latelies to label them as either ‘primitive’ or ‘unsuccessful’? Men have so far survived half a per cent as long." - Richard Fortey, Trilobite: Eyewitness to Evolution. Link to comment Share on other sites More sharing options...
caterpillar Posted September 26, 2017 Share Posted September 26, 2017 Nice. Thanks http://www.paleotheque.fr Link to comment Share on other sites More sharing options...
old bones Posted September 26, 2017 Share Posted September 26, 2017 Beautiful! Thanks for the 'inside story'. Link to comment Share on other sites More sharing options...
ynot Posted September 26, 2017 Share Posted September 26, 2017 It is a nice ammonite, but I do not see a heteromorph here. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
jpc Posted September 26, 2017 Share Posted September 26, 2017 Scaphitids are the least heteropmorphic of the heteromrphs. In the first photo, see that little 'bubble' ion the inside wall of the phragmocone? The phragmocone curls away from the rest of the ammonite for a wee bit, then comes back into contact with it in this case. Pretty subtle. Link to comment Share on other sites More sharing options...
JohnBrewer Posted September 27, 2017 Share Posted September 27, 2017 Nice example John Map of UK fossil sites Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted September 27, 2017 Share Posted September 27, 2017 What JP said. Heteromorphic form is a highly variable, wide spectrum description of form. There are several different form factors or modes of deviation from plain vanilla planispiral ammonites, and different degrees of variation within each of these forms, some ranging from subtle to radical. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
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