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Wrangellian

what kind of heteromorph? Vancouver Island Santonian

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Wrangellian

It's just an impression, but I find so few like this I had to keep it. Looked all over for the positive but could not find it.

It seems so long and narrow for a Bostrychoceras, or is that just an aspect of the impression? 5 whorls visible.

 

 

 

heteromorph-shr.jpg

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FossilDAWG

It sort of looks as if it has nodes along the top of each whorl.  Do you see that or is it a trick of the light on the photo.  Bostrychoceras lacks nodes altogether so if nodes are present it can't be that.  Nodes would suggest a Didymoceras or Nostoceras.  Neither have been reported from the Halsam. Hyphanticeras has been found in the Courtney area but I don't recall that it has nodes. It's a loosly coiled spire with the whorls not in contact, with squared-off ribs.

 

Don

 

 @fossilexpress

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Wrangellian

Boy, it almost looks like there are nodes, now that you point them out, but I think I can see them at the bottom of that whorl too. That is unless that's an artifact of the crushed shell, but it is oddly consistent for a randomly crushed thing... I have seen those Hyphantoceras from Courtenay, that had crossed my mind.

I guess I should go up there and look harder for that positive side! though that pile of rock has been pushed around so much that might be very unlikely.

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fossisle

You can try to make a latex peel, to give you a positive image

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Wrangellian

What do you coat the shale with before you lay on the latex? I've tried that before but without some barrier, it leaves an oily stain.

I'll try for a better pic whenever we get more sun.

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abyssunder

Maybe it helps. :)

 

heteromorph-shr.jpg.585540e79b870d08d8907724212205e3.thumb.jpg.17f9f00060547e8cb6032bee8bed31e5.jpgnegative.thumb.jpg.b02b6945ddf5c73ddbfe2eac6495a76d.jpg

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Wrangellian

Not sure.. I get the best view looking at it in person with my glasses off, and I'm still not sure what I'm seeing. There is one spot where there is a bit of shell left in one of the possible nodes, I could try pulling that out to see if it adds to the appearance of nodes...

Raining here now so I can't get any more photos yet!

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Wrangellian

More shots of it with different lighting angles. I still can't decide whether it has nodes or not, because they could be a result of broken shell.

In some of these the light comes from below which gives the impression of being a positive.

I'm not sure if these help anyone tell, if I can't even tell with it in hand...

 

DSC_0311 cro.jpg

DSC_0312 cro.jpg

DSC_0313 cro.jpg

DSC_0314 cro.jpg

DSC_0315 cro.jpg

 

DSC_0317 cro.jpg

DSC_0316 cro.jpg

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fossisle

That last one is great, Eubostrychoceras

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FossilDAWG

I think the latest photos make it clear the "nodes" result from the way the whorls are flattened and in places partially crushed. I agree with @fossisle, it is a Eubostrychoceras; the way the whorls seem loosely coiled and not in contact suggests perhaps it is E. japonicus which Jim Haggard has identified from the Halsam. 

 

Don

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Wrangellian

OK, well I knew it wasn't the usual Bostrychoceras. Thanks both!

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fossisle
9 hours ago, FossilDAWG said:

I think the latest photos make it clear the "nodes" result from the way the whorls are flattened and in places partially crushed. I agree with @fossisle, it is a Eubostrychoceras; the way the whorls seem loosely coiled and not in contact suggests perhaps it is E. japonicus which Jim Haggard has identified from the Halsam. 

 

Don

Yes and it is the oldest Eubostrychoceras I have seen in the Nanaimo Group, most come from later in the mid Campanian Pender Formation.

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Wrangellian

Older than elongatum?

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fossisle

Bostrychoceras elongatum is the usual Santonian find, Eubostrychoceras is usually found in younger Campanian deposits in my experience. 

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Wrangellian

Oh I see... I assumed Bostry and Eubostry were synonymous.

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