Unidentified Fish (Santana Formation? Rhacolepis buccalis?)

[SophieD]

I recently inherited this fossil fish from my stepdad, who traded a pair of moccasins for it at a rock show in the 80s. The seller claimed it was from the Green River formation, but given the matrix, color, and three dimensionality I highly doubt that. A quick Google search leads me to believe it’s probably from the Santana formation in Brazil and possibly a Rhacolepis buccalis? I’m a geology student but living in invertebrate country I can’t say I know a lot about fish identification  

 

I’m happy to add more pictures as needed or provide what little info I can. Thanks in advance! 

[SophieD]

Here’s a close up of the head, the size limit would only let me attach one photo at once! 

[Fossildude19]

Welcome to the Forum.

 

This looks too robust to be a Rhacolepis buccalis.  I think that this is actually a Brannerion vestitum. 

@oilshale

 

 

[oilshale]

I am not sure either. I admit, the fish looks very robust, but I would still say Rhacolepis. Postorbitalia and Operculum look more like Rhacolepis.

Edited December 9, 2020 by oilshale

[Fossildude19]

2 minutes ago, oilshale said:

I admit, the fish looks very robust, but I would still say Rhacolepis. Postorbitalia and Operculum look more like Rhacolepis.

   

 

Thomas, 

Did Rhacolepis get this large?  You would know better than I. 

I've never seen one this big. 

 

[oilshale]

6 minutes ago, Fossildude19 said:

 

Thomas, 

Did Rhacolepis get this large?  You would know better than I. 

I've never seen one this big. 

 

Upps, 40cm? This is too large for Rhacolepis. The biggest I have seen was about 30cm tall. Also possible is Notelops brama. 

[Fossildude19]

Well, I did find one pretty large one, online, but still seems a bit too robust for Rhacolepis. 

 

 

Notelops brama may be a better match.   

I always forget about Notelops, for some reason.    

 

 

Doing a comparison of fin positions makes it look more like Brannerion, rather than Notelops, though.  

 

 

 

[SophieD]

@Fossildude19 @oilshale

Thank you both so much! I’ve been lurking on the forum for a few years and I’m always amazed by what you guys come up with. As for the Brannerion vs Notelops question, would better pictures of the fins and their location help? Unfortunately they’re not in the best condition, but to me the shape seems slightly more Notelops.

[Fossildude19]

It might help. 

Not sure the details are there to confirm one way or the other, but brighter, more in focus pics of that mid section might help.

I'm still leaning towards Brannerion because of the fin size/location.

[Tidgy's Dad]

Very interesting.

I love this sort of discussion.

Nice fishy, Sophie.