Kem Kem Bone Grab Bag

[Opabinia Blues]

Every year at the Denver fossil show it seems like I pick up some unidentified Kem Kem material. This is because for one it’s cheap, but also because it’s kinda fun to investigate this material.

 

Here are eight pieces I picked up as a bulk set. I have some idea about identification on each of these but would love to hear other’s input. In the following pictures I have the top row being archosaur fossils and the bottom row being fish fossils.

 

My guesses:

1. Caudal(?) vertebra centrum. Croc or theropod, but probably croc.

2. Croc dorsal vertebra

3. Croc centrum

4. Theropod pedal phalanx. Specifically, the distal-most phalanx of toe 1 (the “dew claw”). Narrowest ID I think I could guess we would be Ceratosauria indet., should probably be labeled as Theropoda indet.

5. Two fused fish vertebrae. Are these identifiable any more than this?

6. Gar or gar-like vertebra

7. Chondrichthyan fish vertebra. Maybe Onchoptistis numida? Can that determination even be made?

8. A gigantic ganoid scale. Any guesses just based on size? I’m unfamiliar with all the monster fish in this rock unit.

 

 

 

 

 

 

 

Thanks :)

[Mahnmut]

Hi,

to make a start, 8 is a gar scale as you will probably know.

Best regards

J

Edited September 13, 2023 by Mahnmut

[Opabinia Blues]

8 hours ago, Mahnmut said:

Hi,

to make a start, 8 is a gar scale as you will probably know.

Best regards

J

Well yes, gars do have ganoid scales like that but so do all sorts of other fish within the Holostei. Is there anything there that identifies it as gar specifically? Are there even any gars in the Kem Kem big enough for a scale that size?

[Mahnmut]

Here I stand corrected.

Big ganoid scales like yours seem to be not that uncommon at places referred to as Kem Kem, and I have seen them called gar scales most of the time, Lepidotes sometimes. Though now that you tell me, I see that those labels are rather doubious.

Sorry, I can not provide any helpful information to you.

Best regards,

J