Northern Sharks Posted January 10, 2008 Share Posted January 10, 2008 I know I'm probably asking for miracles, but here's another ammonite that I would like some kind of ID for (at least a genus). The best I can come up with is Dactyloceras or Asteroceras. It is jurassic in age from Lyme Regis, Dorset UK. This one has visible sutures which I tried to show in the second pic. It measures about 1 inch across. As always, whatever help I can get is appreciated. There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Gary Posted January 11, 2008 Share Posted January 11, 2008 It is definately NOT Dactylioceras or Asteroceras. I think it may be Androgynoceras. Link to comment Share on other sites More sharing options...
milou115 Posted January 11, 2008 Share Posted January 11, 2008 Hi all ! Well I disagree with Asteroceras, Dactyloceras and Androgynoceras...sorry about that ! I would say that it comes from upper sinemurian and I will say Promicroceras if it is a Promicroceras in genus it is probably planicosta in specie...if you want I can try to explain my choices... If you want more help try to send a photo of the belly of the ammo (don't know if it is the right word...) Here is a link Link to a page from a very interesting fossil website about english fossils ! The first two photos of ammonites show Dactyloceras from Toarcian the conservation is really different See you ! Very nice ammo ! Mil' Link to comment Share on other sites More sharing options...
Northern Sharks Posted January 12, 2008 Author Share Posted January 12, 2008 Mil: Thanks for the input. Promicroceras was also on my list of possibilities. I'm not sure what you mean by belly, but here's a photo edge on. I'll also add that this ammonite is completely pyritized if that might help narrow down location/age. Gary, thanks also for your input, but it doesn't look like any Androgynoceras I could find on the net. Do you have a reference/example that may change my opinion? I've also just signed up on discussfossils, and I see you're also a member there, so maybe that will be of help, since it is based in the UK. I'll post whatever I find out, if anything There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
milou115 Posted January 12, 2008 Share Posted January 12, 2008 Thank you for the new photo ! it confirms my idea. The internal turns are really characteristic of the genus. Androgynoceras is an ammonite from the Carrixian, the turns grow faster than this ammonite, the costulation is also very characteristic, it is called “capricorne” costulation (cf Aegoceras capricornus), Dommergues a French author about lias created this group of “capricorne” ammonites in which there are Aegoceras, Androgynoceras, Oistoceras, Liparoceras… Then Asteroceras the turns grow faster too, (here they have practically all the same size) the costulation is quite typical too, there are less costs on it, and they have also a special costulation on the bell (often a huge “carene” and two drills) Then most of Dactyloceras are toarcian in age (there are also Prodactyloceras davoie in carrixien), I think you’ve seen their conservation on the site I sent yesterday, all the ways the costulation of Dactyloceras is also characteristic, don’t know how to explain it…all I can say is that it is not the same If you want more precision, I think I can find a diagnose of the genus, for the specie as I said yesterday, Promicroceras planicosta is often found in that England coast. It could also be a Crucibiloceras I have to dig the idea... Unfortunately your ammonite is not complete, sometimes in this small genus the end of it: the “living loge” helps to recognize the specie… I hope that you’ve understood, my English must be quite hard to understand, sorry about it… If you want more precision or anything else…you’re welcome to ask me ! See you Mil’ PS : I do not know the appropriated vocabulary...I'm sorry... Link to comment Share on other sites More sharing options...
Northern Sharks Posted January 13, 2008 Author Share Posted January 13, 2008 Thank you for the new photo ! it confirms my idea.The internal turns are really characteristic of the genus. Androgynoceras is an ammonite from the Carrixian, the turns grow faster than this ammonite, the costulation is also very characteristic, it is called “capricorne” costulation (cf Aegoceras capricornus), Dommergues a French author about lias created this group of “capricorne” ammonites in which there are Aegoceras, Androgynoceras, Oistoceras, Liparoceras… Then Asteroceras the turns grow faster too, (here they have practically all the same size) the costulation is quite typical too, there are less costs on it, and they have also a special costulation on the bell (often a huge “carene” and two drills) Then most of Dactyloceras are toarcian in age (there are also Prodactyloceras davoie in carrixien), I think you’ve seen their conservation on the site I sent yesterday, all the ways the costulation of Dactyloceras is also characteristic, don’t know how to explain it…all I can say is that it is not the same If you want more precision, I think I can find a diagnose of the genus, for the specie as I said yesterday, Promicroceras planicosta is often found in that England coast. It could also be a Crucibiloceras I have to dig the idea... Unfortunately your ammonite is not complete, sometimes in this small genus the end of it: the “living loge” helps to recognize the specie… I hope that you’ve understood, my English must be quite hard to understand, sorry about it… If you want more precision or anything else…you’re welcome to ask me ! See you Mil’ PS : I do not know the appropriated vocabulary...I'm sorry... Mil: Trust me, your English is much better than my French . Your guess of Crucibiloceras looks like it may be a match. I looked at several websites, including yours, and strictly based on the images, it looks very similar. I'll still keep looking, but that is a very good place to start. Merci There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Northern Sharks Posted January 19, 2008 Author Share Posted January 19, 2008 Well it seems unanimous amongst the Brits that this ammonite is indeed Crucilobiceras (and this is the correct spelling). Thanks again Mil for giving me someplace to start. There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
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