Knightia - both?

[Ruger9a]

Good evening folks.  I have two fish, both listed as Knightia and both from Farson Wyoming.  They look similar but they don't look like the same species to me, am I wrong?  These are 10 and 11 year old purchases with the first being dug in the 60's from "near Farson" and the second stating it is from the Green River Formation, Farson.

[Ruger9a]

#2

[Huntonia]

I believe #1 is a Diplomystus and #2 is a Knightia. I've seen a few fish on the market that look like this, wonder if that's natural or part of weird prep that makes them look so pale and ghostly. Maybe someone else knows.

[caldigger]

6 minutes ago, Huntonia said:

wonder if that's natural or part of weird prep that makes them look so pale and ghostly.

Well they are dead!  

[Huntonia]

2 minutes ago, caldigger said:

Well they are dead!  

that sure clears it up! 

[Ruger9a]

26 minutes ago, Huntonia said:

I believe #1 is a Diplomystus and #2 is a Knightia. I've seen a few fish on the market that look like this, wonder if that's natural or part of weird prep that makes them look so pale and ghostly. Maybe someone else knows.

Thanks Huntonia.  The only prep "I" did to the first one was to add a few pieces to the plate and ground off all the rough edges.  On the second, only about 80% of the fish was visible so I had to remove some of the matrix.  The color of the plates is as they were purchased. 

[Ruger9a]

22 minutes ago, caldigger said:

Well they are dead!  

I really need a good laugh today, thanks.

[Ruger9a]

34 minutes ago, Huntonia said:

I believe #1 is a Diplomystus and #2 is a Knightia. I've seen a few fish on the market that look like this, wonder if that's natural or part of weird prep that makes them look so pale and ghostly. Maybe someone else knows.

I checked out both species and I also believe you are correct.  The 1st fish does look like a Diplomystus, thanks again.

[Randyw]

I also believe the first is a diplo. I had a very smart forum member tell me the best way to identify a diplo is the side fin around 1/3 of the way up the body and the long anal ( no snickering) fin.

[grandpa]

So, I'm no expert here; but I do know where to go for some answers.  Here are some resources that may be useful.  I hope this helps.

 

https://en.wikipedia.org/wiki/Knightia

 

https://en.wikipedia.org/wiki/Diplomystus

 

http://www.prehistoric-wildlife.com/species/d/diplomystus.html

 

https://www.thoughtco.com/overview-of-knightia-1093677

 

[Ruger9a]

2 hours ago, grandpa said:

So, I'm no expert here; but I do know where to go for some answers.  Here are some resources that may be useful.  I hope this helps.

 

https://en.wikipedia.org/wiki/Knightia

 

https://en.wikipedia.org/wiki/Diplomystus

 

http://www.prehistoric-wildlife.com/species/d/diplomystus.html

 

https://www.thoughtco.com/overview-of-knightia-1093677

 

Grandpa.  I had already checked out the first two links but not the last three.  Very helpful, thanks for the additional information/confirmation.

[Ruger9a]

9 hours ago, Randyw said:

I also believe the first is a diplo. I had a very smart forum member tell me the best way to identify a diplo is the side fin around 1/3 of the way up the body and the long anal ( no snickering) fin.

Thanks Randyw for the "cheat sheet" identification information and for confirming Huntonia's original diagnosis.

Huntonia/Randyw, I would be correct to change the ID card to Diplomystus for #1 and leave the ID card as Knightia for #2?

[Fossildude19]

@Ruger9a 

 

What are the sizes on these fish? 

[Ruger9a]

Tim they are:  #1 = 3.75 x 1 1/8 inch, #2 = 3.5 x 1 inch. width was taken from the widest part of the body minus any fins.

[Fossildude19]

I am unsure about these fish.  

 

While the first one appears to have some similarities to Diplomystus, I am not seeing the thickened, post cranial support bones typical of Diplomystus. 

The pectoral fins, while upturned, do not appear to be high enough to be Diplomystus, and the upturn to the mouth is not as pronounced as I would expect. 

Dorsal fin appears to me to be a bit farther forward. The caudal fin doesn't appear to have as deep of a V shape to the inner edges. 

I am also not convinced the large anal fin is actually there.

Of course, much of this could be due to preservation in the Farson locality.   

 

 

 

 

The second fish could have more prep done around it. 

Could be Knightia eocaena. 

 

 

 

 

I think it could be possible that one or both are Gosiuteichthys parvus, but I could definitely be mistaken. 

 

 

Try doing some fin ray and vertebra counting. 

See THIS PAPER.

 

@Ptychodus04  @RJB    @sseth

[Ptychodus04]

I would definitely call the 1st one a Knightia. While the anal fin is long, it is not long enough to be a Diplomystus. Also, the pectoral fin is too low for Diplomystus. The compression of the soft tissues makes it appear higher on the body than it actually is.

 

The second one superficially looks like Gosiuteichthys parvus but the main distinction between the two is in the fin rays as @Fossildude19 mentions. With the locality of "near Farson" places the fish in Lake Gosiute making G. parvus a possibility.

[Ruger9a]

2 hours ago, Fossildude19 said:

The second fish could have more prep done around it. 

Could be Knightia eocaena. 

Thanks Tim.  I may be able to prep the second fish a little more on the top portion but the bottom has nothing to remove. The matrix drops off on the bottom of the fish.  I will attempt some additional matrix removal this weekend and post current photos. 

[Ruger9a]

On 3/12/2020 at 1:24 PM, Ruger9a said:

Thanks Tim.  I may be able to prep the second fish a little more on the top portion but the bottom has nothing to remove. The matrix drops off on the bottom of the fish.  I will attempt some additional matrix removal this weekend and post current photos. 

@fossildude  OK, I "tried" and removed some of the matrix from your recommended areas.  Don't know if it made a difference but here are the photos.  I also removed a small amount of the matrix surrounding the head, just in case that would help in the identification.  Wayne

[Ruger9a]

Here are the rest....