We found this ammonite specimen a while ago at Barmston on the Holderness, it is in a small Pyritic 'Cannonball' about 3in across with a double keel and nodes around the edges of the ribs.
I cannot find anything that looks similar in most of the books that I have, so can someone point me in the right direction to it's id?
I hope the images are ok for id.
- Caenisites spp., such as C. tuneri (eg. in http://andysfossils.com)
- Arnioceras sp/? - not sureabout the ribs noding (http://trifoss.com/product_info_sold.php?language=en&products_id=3029&)
- Agassiceras decipiens (see http://community.fortunecity.ws/greenfield/ecolodge/25/unusual.htm)
- some Euhoplites have a double keel, but tend to be knobblier than yours (http://www.gaultammonite.co.uk/Pages/Ammonoidea/Euhoplites_truncatus.htm)
Hi Mike thank's fot the reply, the top three are lower jurassic, lower lias and the bottom one is lower cretaceous and I have to say it doe's have a resemblance to Euhoplites sp.
What has thrown me a bit is because it is in a pyritic nodule and usually they contain upper lias fossils.
The trouble with the Holderness is the beach system contains rocks and fossils from many different geological time periods and sometimes its hard to realise what you have found.
Thank's again for the ID.
Hi Dan, Thank's for the reply.
It's not Arnioceras unfortunately although it doe's look very similar.
You can find Arnioceras multi blocks - death assemblances all along the Yorkshire coast, but the best ones are from the Holderness coast.
For what I can remember the actual beds for this species is at Ravenscar near the peak fault and what you find on the Holderness is because of the last ice age.
I like the south coast Arni's but in my opinion the Yorkshire ones are the best.
I hope you do not mind as I have attached a couple of images of Arnioceras semicostatum multi blocks/death assemblances that I am working on, both from the Holderness.