Coprolite ?

[DDiMatteo]

I found this coprolite (im assuming) on the side of the road in Holbrook, AZ. There were any smaller pieces,and ptrified wood fragments also.

Anyone able to ID what dino left their imprint here, (assuming it's the same one who left it..) The frag measures 2.5" round, the imprint is 1.75" x.75"

Thanks, Dennis (newbie)

[JohnJ]

Welcome to the Forum, Dennis. I think every member we have has learned something here, so stick around.

Don't be too disappointed, but you haven't found a coprolite or a dino imprint. The shapes you see are all geologic in origin...looks like chert (or some other cryptocrystalline rock) with a weathered vug of some other mineral.

[DDiMatteo]

Welcome to the Forum, Dennis. I think every member we have has learned something here, so stick around.

Don't be too disappointed, but you haven't found a coprolite or a dino imprint. The shapes you see are all geologic in origin...looks like chert (or some other cryptocrystalline rock) with a weathered vug of some other mineral.

Aggghhh... and I was so sure it was organic.. I'm surprised it's not..

How about this one? thanks Dennis

[tracer]

welcome to the forum.

i think JohnJ was spot on in his assessment of the first rock, and i'm afraid the second falls into the same category. sedimentary, with a void filled with dissolved mineral precipitating out of solution. the rounded, semi-polished look to the outside indicates it was in a energetic water environment for some time.

if you're looking for coprolites, then you might use google images and search for pictures of them to study. rocks take so many forms that it takes a while to get the "eye" trained for what you find in the field.

good luck with your hunting.

[DDiMatteo]

welcome to the forum.

i think JohnJ was spot on in his assessment of the first rock, and i'm afraid the second falls into the same category. sedimentary, with a void filled with dissolved mineral precipitating out of solution. the rounded, semi-polished look to the outside indicates it was in a energetic water environment for some time.

if you're looking for coprolites, then you might use google images and search for pictures of them to study. rocks take so many forms that it takes a while to get the "eye" trained for what you find in the field.

good luck with your hunting.

Thanks Tracer.. I guess it's back to the books.I appreciate those constructive comments. Living here in RI ,coprolites are a hard find. regards, Dennis

[DDiMatteo]

I know you guys are the experts , but on close up, isn't this a mollusk shell fossil?

The lines just seems so symmetrical, not a shell imprint at least? The outside has the appearance of a turd,I never thought water sculptured this erractic.

I apologize for beating this one more time.

Regards, Dennis

[JohnJ]

An expert, I'm not; I prefer experienced enough to be...(never mind). Yeah, it's possible it could be a bivalve fossil "mold"; but there's not enough there to be definitive. There are much better fossils that an interest can drive you to find.