Ammonite? In North Wales limestone?

[Webryn]

We are on the edge of the Vale of Clwyd in North Wales surrounded by limestone. Much of this limestone is full of fat, coiled fossils which I initially thought were ammonites (on the basis that in my ignorance coiled fossil = ammonite!). I have since learned that there are no ammonites in these rocks - correct?. Today though, my wife was doing some garden digging and found the specimen shown in the photos attached, loose in the soil/rock debris. This looks like an ammonite to me! Can anyone tell me what it is and whether this is its 'birthplace' so to speak. The scale in the pictures is MM.

[FranzBernhard]

Welcome to TFF from Austria!

 

Yes, the fossil in the picture is an ammonite. 

 

It looks like a specimen from Madagascar with its aperture cut-off and the polished surface! Did you find it that way in your garden??

 

Would you like to show us some of the coiled fossils you are finding in the surrounding limestone?

 

Franz Bernhard

[FranzBernhard]

 

17 minutes ago, Webryn said:

my wife was doing some garden digging and found the specimen

Hah! Your wife is playing a trick at you 

Franz Bernhard

[FossilDAWG]

Welcome to the Fossil Forum.

Someone is playing a trick on you, or at least that is clearly a polished ammonite from Madagascar, available from innumerable rock shops around the world.

However, we would like to see the coiled fossils you have been finding.  Depending on the age of the rocks, they may not be ammonites per se, but possibly ammonoids (their evolutionary predecessor) or snails.

 

Don

[Tidgy's Dad]

April Fool's Day is very popular in Wales, or at least it used to be when I visited my relatives there. 

[Webryn]

Thanks for those replies guys - very grateful. But the mystery remains - clearly its got in here somehow, but not from us! I spoke about the abundance of fossils in the limestone here. The vast majority are the type shown in these pictures - coiled tubular, not flat like a disk but with a very shallow cone as the tube coils (does that make sense?). In addition there are crinoids and some big molluscs. You will see that I've had a go at cleaning a couple of them up.

[Webryn]

....and one of these

Regards

David

[FranzBernhard]

Thanks for sharing those! They look very characteristic, but I have no idea, if they are either gastropods (more likely?) or cephalopods.

But there are many knowledgeable members from the UK here on TFF.

@TqB

Franz Bernhard

[FranzBernhard]

Last one could be an aulopora/syringopora coral of paleozoic age.

Are you able to pin down the formation they are coming from?

@Tidgy's Dad

Franz Bernhard

[Tidgy's Dad]

North Wales is principally Mountain Limestone, Lower Carboniferous in age. 

I would agree it's probably a gastropod and one of those types of tabulate coral.

Tarquin might know more.

@TqB

[Webryn]

Dinantian Carboniferous limestone series Dyserth Limestone Group - I'm pulling this off a geological map of the area and this is my best guess

[Ludwigia]

The first ones are definitely gastropods and I would agree with Franz on his assessment of the coral.

[FossilDAWG]

Most of those coiled fossils are gastropods; I am not certain about the third from the bottom one though.  It's not clear but it may have suture lines, which would make it a nautiloid cephalopod.  The corals are Syringopora.  Nice fossils!

 

Don

[Webryn]

Thanks - I'll do a bit of googling around gastrop fossils of the lower carboniferous. See what I can find!

[TqB]

The gastropods look like Euomphalopterus (except maybe the last one, though it may just be because it's a worn internal mould).

 

I agree the coral is a Syringopora. 

[Webryn]

Thanks guys - just did a search on Euomphalopterus as you suggested....definitely the right one. So these things are basically big sea snails yes, like whelks or conchs today, sliding around on the bottom rather than swimming as ammonites did.