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Chillagoe, Australia fossils


Monica

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Hello everyone!

 

Since I can't actually go out fossil hunting these days, I thought I might post pictures of some fossils that I've had for a while to see if anyone out there in TFF can help me with identification.

 

First up are two fossils I collected when I traveled to Queensland, Australia for a field course back in May 2000.  I recall that we spent an afternoon looking for fossils in a creek/river in the Chillagoe area, and I found a total of three specimens:  1. an echinoid (maybe a sand dollar?) that I gifted to my professor because he was interested in it (I now wish that I had kept it, but oh well!), 2. an orthoconic nautiloid (photos found below in this post), and 3. something wierd (photos included in the post that follows).  I'd appreciate any assistance that you can give - thanks!

 

Monica

 

PS - I have no idea as to the age of the rocks out there, but maybe someone out there knows :)

 

Orthoconic nautiloid:

DSCN1322.JPG.35ee546eccfe4ee14ec8c19caead9d5d.JPG

DSCN1323.JPG.224f4574808c3ab53dd99e543f37675e.JPG

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Definitely an ammonite laying  flat in the matrix. 

That needs some prepwork. :)

Nice ones, Monica.

Regards,

    Tim    VETERAN SHALE SPLITTER

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"In every walk with nature one receives far more than he seeks."
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1 hour ago, westcoast said:

Ammonite?

 

26 minutes ago, Fossildude19 said:

Definitely an ammonite laying  flat in the matrix. 

That needs some prepwork. :)

Nice ones, Monica.

Regards,

Hi guys!

 

Could there really be an ammonite in there?!  I thought that it might be an internal cast of a bivalve embedded in...I don't know what.  Wow, an ammonite is pretty exciting for me - I've never found one before because the rocks in my area are too old for them, but I've found a blog (https://natureinfocus.wordpress.com/tag/chillagoe-fossils/) that says that the rocks in the Chillagoe area are Silurian-Devonian, so I guess it would be possible to find both types of cephalopods (orthoconic nautiloid and ammonite) in the same area.  This makes me incredibly happy!!!

 

So I was just wondering - what is that thing sticking up in the middle?  And do you know anyone who could prep this for me - I'd love to see what the little guy inside might look like!

 

Thanks!

 

Monica

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Monica, 


It looks like a bivalve/brachiopod to me, but impossible to tell without some prep done. 

You could try to message MalcolmT and see if he could do it. :) 

Regards,

    Tim    VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM APRIL - 2015  

__________________________________________________
"In every walk with nature one receives far more than he seeks."
John Muir ~ ~ ~ ~   ><))))( *>  About Me      

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Interesting stuff! It looks like there is a bivalve resting on top of (under?) the ammo.

Yes, get Malcolm on it.

I know there is an area in Queensland that produces some wonderful Cretaceous ammonites including heteromorphs, not sure where it is in relation to where you found yours.

(btw, true ammonites are only Jurassic/Cretaceous, maybe uppermost Triassic - everything older that resembles an ammonite we call an ammonoid.)

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In Wrotham Park (north-west of Chillagoe) are two localities, named Walsh River Cliffs and Elisabeth Creek, which contain mixed Lower Cretaceous (Aptian) marine vertebrate and invertebrate fauna, including ammonites, belemnites, bivalves, echinoderms (comatulids), gastropods, fishes, Plesiosaur-Ichthyosaur remains, crustaceans,etc. Fossils within nodules are in excellent condition.

 

My guesses would be:

The ammonite could be a heteromorph ammonite (something in the line of Australiceras-Tropaeum).

The top one could be a bivalve internal mold with shell remains embedded in the matrix.

 

Also, I could be wrong.

 

A good prep would be useful to reveal the truth. :)

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

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As, always, I'm a bit slower... :D

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

My Library

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Great finds Monica.

Chillagoe is just a few hours drive from where I live.

Have been told of a few spots out there to try.

 

Kev.

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Now that looks extremely interesting. There certainly seems to be something ammonoidal in there, perhaps heteromorph as the others are suggesting, and bivalve could be the form at the top. The shell substance looks somewhat delicate and might pop off, but I'm sure that Malcolm could deal with it.

 

Greetings from the Lake of Constance. Roger

http://www.steinkern.de/

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I'm curious about the orthocone, though... I would not expect something like that from the Mesozoic. Is there some Paleozoic in that area too? (except it looks like the same matrix as the ammonite so maybe there is something Mesozoic that would fit that description, I just can't think of it offhand)

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37 minutes ago, Wrangellian said:

I'm curious about the orthocone, though... I would not expect something like that from the Mesozoic. Is there some Paleozoic in that area too? (except it looks like the same matrix as the ammonite so maybe there is something Mesozoic that would fit that description, I just can't think of it offhand)

I know - that's what was giving me trouble, too.  The link that I gave in an earlier post in this thread describes the karsts as being Silurian-Devonian, but we definitely didn't look for fossils there - in fact, I have a picture that I took of my peers walking along/through a shallow creek/river, looking for fossils - that is indeed where I found these items.  So, like you and @abyssunder have stated, it may have been the Walsh River (or apparently it also could have been Elizabeth Creek) that we were hunting along, which would date the rock as early Cretaceous (http://austhrutime.com/fossil_site_walsh_Eiver_elizabeth_creek.htm).  This would be the right time for ammonites but not for orthoconic nautiloids.  Is it possible that what I think is an orthoconic nautiloid isn't that at all?  Could it instead be a piece of an irregularly-coiled (heteromorph) ammonite?  Is there any way to tell?  I can't see any wierdly-patterned sutures indicating an ammonite, but, then again, I haven't tried to look at it under a loupe - perhaps I should do that...

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The "orthocone" looks more like the Phragmocone of a large belemnite. I have seen both from the Cretaceous of Walsh River for sale

Cephalopods rule!!

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  • 6 months later...

Hi all!

 

I'm back with some good news - @Malcolmt has finished prepping my little unknown piece from Australia (thanks again, Malcolm!), and it's definitely an ammonite - yay!!!  I think that it might be an Australiceras jackii (based on pictures I've seen on the internet) - what do you all think?  Please see pictures below:

 

DSCN2209.thumb.JPG.90e25ede89aebcd5629ede00a4fe09e6.JPG

DSCN2219.thumb.JPG.038313d15d5e0562a070c12a4857b775.JPG

 

So, my other piece that I thought was an orthoconic nautiloid must not be that - I think that it is likely what @fossisle has suggested - a phragmocone from a belemnite.

 

Thanks for looking!

 

Monica

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Congrats, Monica and kudos to Malcolm for revealing it! Are there no inner whorls? And I'm still curious as to what that lump in the middle is. I agree with your assessment of Australiceras jackii  at any rate. The "nautiloid" is now definitely a belemnite phragmocone.

 

Greetings from the Lake of Constance. Roger

http://www.steinkern.de/

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2 hours ago, Monica said:

Hi all!

 

I'm back with some good news - @Malcolmt has finished prepping my little unknown piece from Australia (thanks again, Malcolm!), and it's definitely an ammonite - yay!!!  I think that it might be an Australiceras jackii (based on pictures I've seen on the internet) - what do you all think?  Please see pictures below:

 

DSCN2209.thumb.JPG.90e25ede89aebcd5629ede00a4fe09e6.JPG

DSCN2219.thumb.JPG.038313d15d5e0562a070c12a4857b775.JPG

 

So, my other piece that I thought was an orthoconic nautiloid must not be that - I think that it is likely what @fossisle has suggested - a phragmocone from a belemnite.

 

Thanks for looking!

 

Monica

WOW great ammonite!!

Cephalopods rule!!

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I'm glad my assumption related to the ammonite was in the right direction.
Good work Malcolm! :)
What could be the other thing of the matrix, is still a mystery to me. Seems to have some calcitic structure. I speculate with the idea of a septarian nodule/concretion. Could they be part of the infilled propagation cracks?

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

My Library

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The structure in the middle definitely looked organic not mineral and seemed like a very soft calcium carbonate . If you even grazed it with air abrasion it disintegrated immediately. Basicall could only use a high precision scribe.

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Nice Monika !:fingerscrossed:

 

For the second item, see if it is hollow, if so it's a belemnite.

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"We only well see with the heart, the essential is invisible for the eyes."

 

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