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NatalieinFlagstaff

Arizona Coral?

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NatalieinFlagstaff

Hello! While rock hounding in our favorite local spot near Gray Mountain, AZ I found this beautiful coral. The fine details preserved fascinate me- I can stare at this fossil through a loupe all day. Can anyone identify it for me? It was found on the surface, but other marine fossils I have found in the same location have been suggested to be from Permian Kaibab limestone. Our rock hounding site is the tailings from old uranium mines operating in the 1950's I believe. Thank you!

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NatalieinFlagstaff

Here is an assortment of other fossils found at the same place.

20200914_220903.jpg

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DPS Ammonite
9 minutes ago, NatalieinFlagstaff said:

Hello! While rock hounding in our favorite local spot near Gray Mountain, AZ I found this beautiful coral. The fine details preserved fascinate me- I can stare at this fossil through a loupe all day. Can anyone identify it for me? It was found on the surface, but other marine fossils I have found in the same location have been suggested to be from Permian Kaibab limestone. Our rock hounding site is the tailings from old uranium mines operating in the 1950's I believe. Thank you!

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I have heard of horn coral in the Kaibab, never any coral similar to this. My guess is that this is coral, but bryozoans and Chaetetes sponges also look similar. 
 

Consider contacting NAU retired paleontologist Dave Elliott:

David.Elliott@nau.edu

 

Let us know what he says.

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Rockwood

The same thought has been pestering me this morning.

Somehow the look just isn't quite coral-like enough. It's a shame the 'face' pattern isn't exposed better.

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oyo

External surface is very typical in these sponges but both longitudinal and transverse sections are also. This specimen shows large areas in longitudinal section but also some small areas in cross section. It is a very beautiful specimen, no wonder the owner does not stop looking at it with a magnifying glass.:thumbsu:

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NatalieinFlagstaff
10 hours ago, DPS Ammonite said:

I have heard of horn coral in the Kaibab, never any coral similar to this. My guess is that this is coral, but bryozoans and Chaetetes sponges also look similar. 
 

Consider contacting NAU retired paleontologist Dave Elliott:

David.Elliott@nau.edu

 

Let us know what he says.

Possibly a sponge! Very interesting. Thank you, I will look into that. I have reached out to others in the geology depts at NAU in the past but never received any responses. Thank you for David Elliott's email- I could not find it anywhere on NAU's website in the past. I would very much like to begin a dialogue with him :) I will let you know what I discover. 

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NatalieinFlagstaff
7 hours ago, oyo said:

External surface is very typical in these sponges but both longitudinal and transverse sections are also. This specimen shows large areas in longitudinal section but also some small areas in cross section. It is a very beautiful specimen, no wonder the owner does not stop looking at it with a magnifying glass.:thumbsu:

Thank you oyo! I will look at that link as soon as I have time to sit down :) As a newbie, I have heard that sponges are more rare to find than coral, so the fact that this is likely a sponge is exciting :) And a beautiful specimen too? How amazing! I seriously do examine my rock and fossil collection as a stress relieving activity ;) Would you by any chance be able to point me out to any petrified wood experts on this forum? I have found a rare petrified wood species at the same location, and some more that I have been unable to identify as yet...thank you!!

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NatalieinFlagstaff

@DPS Ammonite would you possibly be able to point me out to a petrified wood expert as well? I have some unusual specimens that I would love to show someone. Thank you!!

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NatalieinFlagstaff

@DPS Ammonite thank you for the referral to Walt Wright. That's too bad what happened to him though! 

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oyo
19 hours ago, NatalieinFlagstaff said:

Thank you oyo! I will look at that link as soon as I have time to sit down :) As a newbie, I have heard that sponges are more rare to find than coral, so the fact that this is likely a sponge is exciting :) And a beautiful specimen too? How amazing! I seriously do examine my rock and fossil collection as a stress relieving activity ;) Would you by any chance be able to point me out to any petrified wood experts on this forum? I have found a rare petrified wood species at the same location, and some more that I have been unable to identify as yet...thank you!!

Nice/ugly is a very relative and personal assesstment, for me is a very nice one. The same thing occurs with rare/common, this type of materials are not very rare but not very common. Medium size in scale rare/common:heartylaugh:.

I'm sorry I can't help you in terms of experts in the forum but I've been here for a short time and I don't know the public.

Take care of your stress.

Regards.

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NatalieinFlagstaff

I sent those photos to Dr. Elliott, retired NAU Professor. Here is a screenshot of his response. 

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FranzBernhard

Now you are going to see the tabulae! Please examine the longitudinal sections of the colums closely. There must be some tabulae.

Btw, do all tabulate corals contain tabulae?

Franz Bernhard

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DPS Ammonite

Thank you Dave for your reply.


I see the tabulae. By the way I have seen similar Chaetetes sponges and massive bryozoan in Arizona that have structures that look like tabulae under a hand lens.

 

A big question I have is it from the Kaibab which should be the most prevalent fossil bearing Paleozoic unit in the area. Has that species been found in the Kaibab before? 

7D0AD794-4E20-415D-81CF-81ED9F480142.jpeg

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DPS Ammonite
36 minutes ago, FranzBernhard said:

Btw, do all tabulate corals contain tabulae?

Franz Bernhard

According to the Digital Atlas of Ancient Life:

 

“A defining feature of most tabulate corals is the presence of structures called tabulae, which give them their name.“
 

Therefore some do not have tabulae.

 

https://www.digitalatlasofancientlife.org/learn/cnidaria/anthozoa/tabulata/


 

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TqB

 I agree it's a chaetetid. The structure and tube size are right.

They have tabulae (not sure if they're actually called that in calcisponges) and were thought to be tabulate corals until quite recently but have been found to have spicules in the walls which clinches their reassignment to sponge.

 

Here's a Mississippian Chaetetes.

Scale in mm.

 

IMG_0332.thumb.jpeg.86529729f9015bd22d17271cdfc2d109.jpeg5f631c62b6413_IMG_03322.thumb.jpeg.6369a44e27fbd9684b933c3ba4f6064b.jpegIMG_0333.thumb.jpg.40008c81580184da712cbf6e2caf19be.jpg

 

Edited by TqB

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Rockwood

:chatter:

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oyo

I think we've put the kind Dr. Dave Elliot in a trouble. Without being a specialist in corals, ask him for an opinion on this bug is very problematic.

I still think it's a chaetetid sponge. Very clearly.

As TqB says it were considered tabulate corals until have been found to have spicules in the walls which clinches their reassignment to sponge. The presence of tabulae like structures, pseudoseptes or thorns inside the tubes, general aspect and vertical poligonal tubes, as Dr. Dave Elliot says,  suggest tabulate corals.

Attached a couple of images of Acanthochaetetes eocenus from Eocene (Lutetian) that shows tabulae like structures, thorny pseudoseptes and vertical poligonal tubes. General structure could lead to think of a tabulate coral but obviously, given the stratigraphy of the sample, it is something impossible.

 

 

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DSCN0348.JPG

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henpecked

The people on this forum are top notch. Always helpful and if they don't know willing to point you in the right direction.

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NatalieinFlagstaff

Okay, I very much appreciate everyone's input! I got out a microscope which attached to my phone. It can magnify up to 30x. Here are some pictures I just took. I think I can see the lines which are the tabulae. Trying to look into the tiny openings of the septum (is that right?) is difficult but I tried to get some shots of that as well. Let me know what you think after seeing these closeups. 

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NatalieinFlagstaff

A couple more photos...

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NatalieinFlagstaff

20200917_205438.jpg

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oyo

We see what we expected to see, the basic elements that we had already talked about. We had said that it are elements common to tabulated corals and chaetetid sponges.
I believe that the key in this matter, as TqB has already told you before, is the size of the "corallites". It are very small in size in the case of the chaetetids sponges as shown by your specimen.

I hope it helps you.

Best regards.

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DPS Ammonite

The only known chaetitids from the area are from the Pennsylvanian Naco Formation about 50 miles to the south. Transportation to the Gray Mountain area via the Tertiary Rim Gravels is possible but unlikely. If the preponderance of the fossils are from the nearby Permian Kaibab Formation then the Kaibab is the most likely source. 
 

If there is more than one piece of “Chaetetes” in the area, you might ask Elliott if he would like a piece for their Kaibab reference collection; it might be a new species for the Kaibab. I may also help you put a piece into the Arizona Museum of Natural History.
 

I mentioned that it also might be a bryozoan. I have collected likely massive/encrusting bryozoans from the Naco that appear to have tabulae like structures. The openings average about 0.25 mm across. In other words do not dismiss that yours might be a bryozoan. 
 

Does anyone know if the size of the openings in Natalie’s fossil (~ 1 mm) exceeds that of any known Paleozoic bryozoan?

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Edited by DPS Ammonite

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