Probably a sponge but....

[Kaibabian]

This was found among one of the large chert layers in the permian Kaibab Limestone. The sponge, Actinocoelia, is very common in this layer but this seems different or is at least a different presentation or segment of it. It's nearly perfectly round. It's diameter is 3 1/2 cm.

[DPS Ammonite]

I am not seeing anything that looks obviously like a sponge. It might be a really poorly preserved bivalve or a mini hamburger slider. I have never heard of more than one sponge variety in the Kaibab. That is sort of odd since their are several varieties each in the underlying Fort Apache Limestone and the Naco Formation.
 

Keep on looking. Someday we will have to get together so I can see your unknowns in person. Keep looking for interesting stuff.

[Kaibabian]

7 minutes ago, DPS Ammonite said:

I am not seeing anything that looks obviously like a sponge. It might be a really poorly preserved bivalve or a mini hamburger slider. I have never heard or more than one sponge variety in the Kaibab. That is sort of odd since their are several varieties each in the underlying Fort Apache Limestone and the Naco Formation.
 

Keep on looking. Someday we will have to get together so I can see your unknowns in person. Keep looking for interesting stuff.

Hamburger slider! I will tell you that it is extremely pleasing to hold in your hand. The Orthocone nautiloid you identified for me I couldn't find in any of the literature about the Kaibab limestone although I found examples in other areas that seem to confirm your identification. I found another straight nautiloid yesterday although very different looking. My friend has several nicely preserved straight nautiloids from the Kaibab. Are they known in the Kaibab and just not mentioned in the literature or are they one of the reported ones, 

Aulametacoceras sp., Metacoceras unklesbayi, Stearoceras sp., Tainoceras sp. (taken from the Walnut Canyon National Monument Paleontological Resource Inventory)?

[DPS Ammonite]

47 minutes ago, Kaibabian said:

Hamburger slider! I will tell you that it is extremely pleasing to hold in your hand. The Orthocone nautiloid you identified for me I couldn't find in any of the literature about the Kaibab limestone although I found examples in other areas that seem to confirm your identification. I found another straight nautiloid yesterday although very different looking. My friend has several nicely preserved straight nautiloids from the Kaibab. Are they known in the Kaibab and just not mentioned in the literature or are they one of the reported ones, 

Aulametacoceras sp., Metacoceras unklesbayi, Stearoceras sp., Tainoceras sp. (taken from the Walnut Canyon National Monument Paleontological Resource Inventory)?

Here is a very interesting article that talks about fossil found at the Grand Canyon that is loaded with references. McKee found Orthoceras nautiloids in the Kaibab. Most interesting to me is the presence of several undescribed sponges.

 

Chapter 5. Paleozoic Invertebrate Paleontology of Grand Canyon National Park. By Linda Sue Lassiter, Justin S. Tweet, Frederick A. Sundberg, John R. Foster, and P. J. Bergman

https://irma.nps.gov/DataStore/DownloadFile/637947

 

Here is the multi chapter 2020 report, goof stuff: 

Grand Canyon National Park
Centennial Paleontological Resource Inventory (Non-Sensitive Version)
Natural Resource Report NPS/GRCA/NRR—2020/2103
12 VincentL.Santucci andJustinS.Tweet, editors

 

https://irma.nps.gov/DataStore/Reference/Profile/2272500

 

https://www.researchgate.net/publication/340549989_Santucci_V_L_and_J_S_Tweet_editors_2020_Grand_Canyon_National_Park_Centennial_paleontological_resource_inventory_non-sensitive_version

Edited July 17, 2020 by DPS Ammonite

[Kaibabian]

25 minutes ago, DPS Ammonite said:

Here is a very interesting article that talks about fossil found at the Grand Canyon that is loaded with references. McKee found Orthoceras nautiloids in the Kaibab. Most interesting to me is the presence of several undescribed sponges.

 

Chapter 5. Paleozoic Invertebrate Paleontology of Grand Canyon National Park. By Linda Sue Lassiter, Justin S. Tweet, Frederick A. Sundberg, John R. Foster, and P. J. Bergman

https://irma.nps.gov/DataStore/DownloadFile/637947

 

Here is the multi chapter 2020 report, goof stuff: 

Grand Canyon National Park
Centennial Paleontological Resource Inventory (Non-Sensitive Version)
Natural Resource Report NPS/GRCA/NRR—2020/2103
12 VincentL.Santucci andJustinS.Tweet, editors

 

https://irma.nps.gov/DataStore/Reference/Profile/2272500

 

https://www.researchgate.net/publication/340549989_Santucci_V_L_and_J_S_Tweet_editors_2020_Grand_Canyon_National_Park_Centennial_paleontological_resource_inventory_non-sensitive_version

 

[Kaibabian]

Thanks for the links! It seems to me there’s a Masters project to describe the orthoceras naultiloids. If my friend and I have at least 6 specimens,  the GCNP and/or NAU have to have some, no? My friend and his son have found unnamed shark teeth that the team at NAU (Hodnett) said they’d described one day. They used to live feet from the micro- site where the devil shark tooth was found. It would be interesting to know what the other sponges look like. I’m definitely going to keep my eye out for them. Maybe they look like hamburgers!