Dinosaur coprolite #1 ID confirmation Request

[Ruger9a]

Good afternoon folks.  I have what was identified as a Sauropod coprolite (1 of 5) from the Morrison Formation, Henry Mountains, Wayne County, Hanksville, Utah.  Jurassic period (Per the seller's description).  I purchased this back in 2000 and am requesting a verification so I can ensure my ID card is correct.  All help is appreciated.  Measurements are 8.5Cm W, 6.0Cm H, 4.5Cm D. 

[Ruger9a]

@GeschWhat  help please.

[GeschWhat]

The jury is still out on this type. For the most part, I would say most of the siliceous "coprolites" coming from the Morrison Formation are not coprolites. I only have one that I can say with any degree of confidence is really a coprolite and that one looks like it may have a bit of bone in it, making it a carnivore coprolite. That said, yours does have possibilities. The lighter areas look like they could be backfilled burrows that could have been left by something akin to a dung beetle. That would give your specimen a little more street cred than most I've seen. It also looks like there may be inclusions. From the photos, I can't tell if it is plant material. Do you have a microscope? 

 

Verified herbivore coprolites that I am aware of are calcareous. Does the surface fizz if you put vinegar on it? 

[Ruger9a]

17 hours ago, GeschWhat said:

The jury is still out on this type. For the most part, I would say most of the siliceous "coprolites" coming from the Morrison Formation are not coprolites. I only have one that I can say with any degree of confidence is really a coprolite and that one looks like it may have a bit of bone in it, making it a carnivore coprolite. That said, yours does have possibilities. The lighter areas look like they could be backfilled burrows that could have been left by something akin to a dung beetle. That would give your specimen a little more street cred than most I've seen. It also looks like there may be inclusions. From the photos, I can't tell if it is plant material. Do you have a microscope? 

 

Verified herbivore coprolites that I am aware of are calcareous. Does the surface fizz if you put vinegar on it? 

Thank you, Lori.  I do have a microscope and will "try" to take some close up shots if you can direct me as to what I should be concentrating on.  Have not tried the vinegar test, what dilution amount would you recommend?  And for how long?

[Ruger9a]

@GeschWhat  I didn't see the sense in posting the last two sets of photos as they are basically the same.