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The Amateur Paleontologist

Heteromorph: The rarest fossil ammonites (Nature at its most bizarre)

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Wrangellian
12 minutes ago, The Amateur Paleontologist said:

@Wrangellian Yeah... thing is, I wasn't very surprised about the location. After all, Glyptoxoceras does have quite a vast geographic range, doesn't it? @caterpillar showed one to us from southern France, in this thread :)

Yes, but specifically subcompressum? Usually other G's from other places and other stages are a different species.

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The Amateur Paleontologist
10 hours ago, Wrangellian said:

Yes, but specifically subcompressum? Usually other G's from other places and other stages are a different species.

I checked the FossilWorks record of Glyptoxoceras, and though it doesn't show the subcompressum species, it does indicate that it lived until the latest Maastrichtian..

-Christian

 

P. S. I really like those Pseudoxybeloceras you posted, they're rather cool :)

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Wrangellian
2 hours ago, The Amateur Paleontologist said:

I checked the FossilWorks record of Glyptoxoceras, and though it doesn't show the subcompressum species, it does indicate that it lived until the latest Maastrichtian..

-Christian

P. S. I really like those Pseudoxybeloceras you posted, they're rather cool :)

Thanks.

Is that the same as the old Paleobiology Database? I recall that it didn't have info on species, it only went down to genus. I'm not surprised that the genus lasted into the Maastrichtian. Also it started in the Turonian - almost the whole Late Cretaceous.

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Heteromorph
19 hours ago, Wrangellian said:

I hate to post things I've posted before, I really need to get some new photos of other stuff to show! But here are 2 of my ?Pseudoxybeloceras specimens (self-found, local).

post-4372-0-49762100-1424991762_thumb.jpgpost-4372-0-01642700-1424992111_thumb.jpg

Beautiful specimens! Did you use anything to stabilize them during excavation? Most large heteromorphs that I try to excavate end up in pieces. 

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KimTexan
On 6/2/2018 at 9:08 AM, The Amateur Paleontologist said:

A few from my personal collection (WARNING: not many :()

 

Fairly long fragment of a thin (uncommon form) Hamites sp. from the Late Cretaceous of Cap Blanc-Nez (Pas-de-Calais, France)

 5b12a37f059ed_ScreenShot2018-06-02at16_01_09.png.293764cefaf7e159dd6838f2521eb926.png

Thanks for sharing. I’m getting an education here.

Interesting. I’m not familiar with that one, however about 10 days ago I was out hunting and came across an imprint of something I had never seen before, which must have been something like that. I did not know a long straight one like that existed. The rock had maybe 4 other at least partial Idahomites in it so I took it home.

It is hard to tell, but the imprint is 8 cm long.

5F8DC879-D84F-4AEF-8A68-B9BAE8196178.thumb.jpeg.35114fa30b2ecab9116b2953746345b1.jpeg

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FossilDAWG
21 hours ago, Wrangellian said:

Yes, but specifically subcompressum? Usually other G's from other places and other stages are a different species.

Glyptoxoceras subcompressum was originally described from the Late Cretacous of Pondicherry, India.  Recent revision of the age of these rocks indicate that they are all Maastrichtian, in contrast to previous assessments that concluded some Campanian was present.  This means the species definitly occurs in the Maastrichtian.  It is the Vancouver Island occurrance that is problematic.  Somewhere (probably one of Kennedy's papers) I recall reading that Glyptoxoceras is a bit of a muddle; some species (including the Vancouver Island "G. subcompressum") start out as a small turret, then develop into an expanding series of helical whorls.  Others, such as G. rubida from the Pierre Shale and equivalents in the North American Western Interior, start with helical whorls (like a spiral with the whorls not in contact) right away, there is no turret stage.  Probably these should be split as different genera.  The problem is the initial whorls are not known for most species (including the Indian "G. subcompressum" as I recall) so those species could not be assigned to the correct genus.  I would not be surprised if one day the Vancouver Island "Glyptoxoceras subcompressum" ends up with a completely different name.

 

BTW those specimens of Glyptoxoceras subcompressum from western Australia (in the photo a few posts before this one) look a little "off" to me.  In particular one specimen is completely straight, which seems odd for a Glyptoxoceras.  Possibly the straight piece at least is a Ryugasella or Diplomoceras.  Straight fragments of Ryugasella are found in the Haslam Formation along with Glyptoxoceras.  Unfortunately no complete specimens are known from anywhere so the shape of the entire shell is a mystery.

 

Don

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KimTexan
On 8/3/2018 at 2:50 AM, caterpillar said:

Always from upper santonian of southwest France

Glyptoxoceras souqueti and Amapondella amapondense

Glyptoxoceras souqueti 1.jpg

Glyptoxoceras souqueti.jpg

Eubostrychoceras (Amapondella) amapondense.jpg

Eubostrychoceras (Amapondella) amapondense 6.jpg

I was looking at these again today and was impressed by their quality, prep and photography.

Are these personal finds? Quite lovely if so.

On 8/6/2018 at 1:34 PM, The Amateur Paleontologist said:

@KimTexan @Wrangellian @caterpillar

These are some heteromorphs exhibited at the Oxford University Museum of Natural History 

20160708_172035.jpg

20160708_172439.jpg

20160708_172534.jpg

Very cool. I really like the 2nd one that has the nacre on it.

 

I did not know this was a show us your baculites thing too. I have some as well. Not the highest quality, but I’m happy to have found them.

These are Sciponoceras gracile from the Eagle Ford, Britton Formation late Cretaceous. The first one is a beautiful coppery bronze look of nacre I guess.

IMG_7739.jpg.cb56ea7bd72820c992b7d02c012fd39f.jpg

 

Pieces I found in 2 trips. I have a bunch of very slender ones in my cephalopod hash plates. They are the tiniest baculites I have ever seen, almost needle thin.

IMG_7747.jpg.e73d8f9f48d75fab11b455abe94dafd1.jpg

 

These are my larger baculites from the North Sulfur River in Texas, upper Cretaceous, Ozan formation.

They are Baculites sp. cfr. aquilaensus.

I have a number of little phosphatized fragments. I included a fragment with the sutures showing.

The one with the white. It was the first larger one I found the area in White was originally there, but it had so much pyrite that it practically turned to dust when I moved it. I am not into prepping. I need to find someone to mentor me in that area.

DA66C9DF-ABBC-493C-9988-4BF7EED1BD68.thumb.jpeg.05bb1a9537b8ebfa096b638fa19ddc98.jpeg

 

 

These are orthoceras from Iowa that @Nimravis sent to me.

B0D88CB9-263B-4E94-936D-43D4D0320949.thumb.jpeg.e474b18231b13fec02eced15384a15f2.jpeg646A2B40-25CE-4F20-BD89-0FEB56D9A315.thumb.jpeg.25c628c00d46470c3eddc94aa3f2e098.jpeg

 

This is something I posted for ID, but no one was able to ID it. I’m certain it has to be a type of cephalopod. It was found in Oklahoma near the town of Gene Autry. It was found in an area I believe to be Desmoinesian, Pennsylvania. I personally think it must be a type of pseudoorthoceras.

01F15AE9-E759-4B84-8C66-DC976EAB0F20.thumb.jpeg.493ecdbcfc71ea9220818887efbec2ef.jpegD1F5AF79-CA3B-4B9B-A913-0EA41CDD4198.thumb.jpeg.145d1ebdfa0b407ed6601c297a5bfe5a.jpeg

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Wrangellian
7 hours ago, FossilDAWG said:

...  I would not be surprised if one day the Vancouver Island "Glyptoxoceras subcompressum" ends up with a completely different name.

 

Based on what you say, nor would I!

It almost looks like there are two forms of Glyptoxoceras here, and you've probably seen them - one is concentric circles as you say, the other starts to uncoil sooner into more of a 9 shape. I've got examples of each. Maybe it's just slight variation within the species (whatever species that is). What do you think?

 

 

Glyptox1.jpg

Glyptox2.jpg

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Wrangellian
9 hours ago, Heteromorph said:

Beautiful specimens! Did you use anything to stabilize them during excavation? Most large heteromorphs that I try to excavate end up in pieces. 

Usually I have to insert glue into the cracks before I start to excavate, but even then it doesn't always work out ideally. Both required a bit of reassembly and stabilization after excavation too (the matrix more than the ammo's themselves).

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Heteromorph
Just now, Wrangellian said:

Usually I have to insert glue into the cracks before I start to excavate, but even then it doesn't always work out ideally. Both required a bit of reassembly and stabilization after excavation too (the matrix more than the ammo's themselves).

Super Glue for excavation? If so, the gel or the regular? 

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KimTexan
34 minutes ago, Heteromorph said:

Super Glue for excavation? If so, the gel or the regular? 

Super glue or a form of it is used abundantly in digs. The dig I go to in Wyoming, every digger has it in their kit to stabilize anything they find in need of it before it is put in a plaster cast or if small being wrapped in foil.

You may find this helpful.

http://nautarch.tamu.edu/CRL/conservationmanual/File2.htm

 

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FossilDAWG
2 hours ago, Wrangellian said:

Based on what you say, nor would I!

It almost looks like there are two forms of Glyptoxoceras here, and you've probably seen them - one is concentric circles as you say, the other starts to uncoil sooner into more of a 9 shape. I've got examples of each. Maybe it's just slight variation within the species (whatever species that is). What do you think?

 

 

Glyptox1.jpg

Glyptox2.jpg

Interesting figure.  Where is it from?  I have not seen that one before.

Don

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Wrangellian
2 hours ago, Heteromorph said:

Super Glue for excavation? If so, the gel or the regular? 

At the time I was using white glue. It was winter when I collected both of those so probably that was the only kind of glue I could have used, because there was some degree of wet/dampness. Now I normally use Super/Crazy glue (PaleoBond) to stabilize everything before excavation, or thin Acryloid, but only if I'm confident that it's dry, and it would have to be the runny stuff to wick down into all the cracks. Last year I only had some thicker Acryloid handy when I found a nice crinoid (not quite a gel but thicker than it should have been), and when I started to excavate it after letting it set for a couple hours, it came out in so many pieces because it had not wicked into the cracks properly. I really needed a thinner solution, or else PaleoBond.

My stuff is in splintery shale/mudstone - your matrix might be different...?

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Wrangellian
5 minutes ago, FossilDAWG said:

Interesting figure.  Where is it from?  I have not seen that one before.

Don

Both are from 'A Field Guide to the Trent River Formation near Courtenay BC' prepared by Rolf Ludvigsen and Mike Trask for the First BC Paleo Symposium in 1995.

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Heteromorph
33 minutes ago, Wrangellian said:

At the time I was using white glue. It was winter when I collected both of those so probably that was the only kind of glue I could have used, because there was some degree of wet/dampness. Now I normally use Super/Crazy glue (PaleoBond) to stabilize everything before excavation, or thin Acryloid, but only if I'm confident that it's dry, and it would have to be the runny stuff to wick down into all the cracks. Last year I only had some thicker Acryloid handy when I found a nice crinoid (not quite a gel but thicker than it should have been), and when I started to excavate it after letting it set for a couple hours, it came out in so many pieces because it had not wicked into the cracks properly. I really needed a thinner solution, or else PaleoBond.

My stuff is in splintery shale/mudstone - your matrix might be different...?

Thanks! Mine is nodular chalk. Pretty hard matrix compared to shale/mudstone, but still subject to small cracks that can turn into big cracks during excavation. I had a beautiful heteromorph Phlycticrioceras trinodosum that looked great in-situ crack into multiple big pieces and many small, unrecoverable bits during excavation, and I don’t want that to happen again. 

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Wrangellian
16 hours ago, Heteromorph said:

Thanks! Mine is nodular chalk. Pretty hard matrix compared to shale/mudstone, but still subject to small cracks that can turn into big cracks during excavation. I had a beautiful heteromorph Phlycticrioceras trinodosum that looked great in-situ crack into multiple big pieces and many small, unrecoverable bits during excavation, and I don’t want that to happen again. 

Been there, done that. In cases like that, your only option might be the gas-powered masonry saw! (diamond disc)  I'd have to see the situation to comment, but sometimes there is no other way to avoid cracks - The glue is only so strong, and if the force needed to loosen the rock is beyond the strength of the glue and the natural fractures in the rock, cracks will happen.

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KimTexan

@Heteromorph In that type of material you have to start a much further distance than you think nesseccary from the specimen. Then you have to chisel away at it. I’m getting better at extracting stuff from tough matrix. Part of it is having the tools. A rock hammer alone won’t cut it.

I carry 2 sets of chisels in my car. One set has hand guards. They are for the heavy duty work with a sledge hammer. The other set is finer chisels for splitting layers or taking out small things or more detailed and precise.

When you go with me to the Grayson it is best to have a set of both. I’ll have mine with me if you need to borrow them. The Grayson marl can be pretty tough at times, kind of a bit like limestone. So you have to break out the sledge hammer and heavy duty chisels if one of us find a Graysonites  we must have. Other parts of it are like hard shale with a little chalk quality to it. Hopefully we will get some good rain this week that will turn up some new stuff. There are 3 varieties of regular urchins there too.

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