Mystery Fossils from the upper Cambrian

[Arizona Chris]

Hi all

 

Were going through the last fossils from our long series of trips to the Cambrian Abrigo formation in south eastern Arizona, and we have a few fossils that I have not seen before.  My thoughts are some sort of stem ossicle or foram like animal.  What do you think?  Have you seen such a thing before?

 

Thanks.

[FossilDAWG]

Not anything that I am familiar with.  Interesting!

 

Don

[GeschWhat]

Very interesting. I've seen something similar once before in Triassic coprolites from the Bull Canyon Formation in Quay County, NM. Unfortunately, I was never able to identify them. 

[Arizona Chris]

FossilDawg - This one slab was the only one we found like this and was in an area with trilobite hash, hyalithids and such..  maybe pieces of an eocrinoid?  The holes are suggestive.

 

Geshwhat - reminds me of something called a "pisolith".  But no holes like in mine...

[DPS Ammonite]

First guess is that they are sponges or eocrinoids. See your prior post.

 

Woorster Geologists website:

https://woostergeologists.scotblogs.wooster.edu/2014/10/03/woosters-fossils-of-the-week-eocrinoid-holdfasts-on-a-middle-ordovician-hardground-from-utah/

 

See Wikipedia article on eocrinoids. See photo of holdfasts.  https://en.m.wikipedia.org/wiki/Eocrinoidea

 

They might be ooliths and or oncoliths (although they do not have holes in them like most of yours). See figures 12 and 13. This paper mentions and pictures many trace fossils and sedimentary structures found in the Abrigo:

 

https://www.researchgate.net/profile/Brian_Pratt/publication/290648847_Depositional_Dynamics_In_A_Mixed_Carbonate-Siliciclastic_System_Middle-Upper_Cambrian_Abrigo_Formation_Southeastern_Arizona_USA/links/5ec573a1299bf1c09acf9297/Depositional-Dynamics-In-A-Mixed-Carbonate-Siliciclastic-System-Middle-Upper-Cambrian-Abrigo-Formation-Southeastern-Arizona-USA.pdf

 

Łabaj, Marcelina & Pratt, Brian. (2016). Depositional Dynamics In A Mixed Carbonate–Siliciclastic System: Middle–Upper Cambrian Abrigo Formation, Southeastern Arizona, U.S.A.. Journal of Sedimentary Research. 86. 11-37. 10.2110/jsr.2015.96. 

[abyssunder]

On 6/19/2020 at 1:21 PM, GeschWhat said:

Very interesting. I've seen something similar once before in Triassic coprolites from the Bull Canyon Formation in Quay County, NM. Unfortunately, I was never able to identify them. 

Hello Lori, I think you have ooids in your picture.

[GeschWhat]

On 6/19/2020 at 5:06 PM, abyssunder said:

Hello Lori, I think you have ooids in your picture.

Would they form in a coprolite?

[abyssunder]

20 hours ago, GeschWhat said:

Would they form in a coprolite?

I never heared about that.