HeatherT Posted October 9, 2017 Share Posted October 9, 2017 While hiking a dry riverbed I came across this. It has a few shell imprints, which is very common here, but the rounded area I've never seen before. Is this a fossil or have I just come across a neat rock formation? I'm still trying to resize the photos but if you need a different picture, let me know. Thanks! Link to comment Share on other sites More sharing options...
abyssunder Posted October 9, 2017 Share Posted October 9, 2017 Welcome to the Forum! I don't know what could be the specimen in question, but the matrix is full of fan-shaped bryozoans. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Fossildude19 Posted October 9, 2017 Share Posted October 9, 2017 Welcome to the Forum. Looks like it could possibly be a crinoid calyx, preserved in chert or flint. Let's see what some others have to say. EDIT: PS - good pictures! 1 Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Rockwood Posted October 9, 2017 Share Posted October 9, 2017 I think it's an internal mold of a calyx. 1 Link to comment Share on other sites More sharing options...
Miocene_Mason Posted October 9, 2017 Share Posted October 9, 2017 I agree with calyx internal mold, the outside is worn so I'm not sure much more than that can be determined. Nice! “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
abyssunder Posted October 9, 2017 Share Posted October 9, 2017 Crinoid calyx internal mold might be a good ID. Maybe its life position can be determined. I'm guessing was this: " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Arizona Chris Posted October 9, 2017 Share Posted October 9, 2017 Looks like mississipian chert. The dotted lines are fan shaped bryozoans, this round object is a steinkern of a crinoid calyx, maybe abatocrinus? If you look closely around the steinkern, you can see the exterior mold of the outside of the calyx as bumpy. The thin gap in between is where the enclosing "shell" or calyx as it is called was before it was dissolved out. My guess. Also to the lower right of the calyx, those dark spots look to be dolorhombs. 1 ---------------------------------------------------------------------------------------------------------------------------- Arizona Chris Paleo Web Site: http://schursastrophotography.com/fossiladventures.html Link to comment Share on other sites More sharing options...
Rockwood Posted October 10, 2017 Share Posted October 10, 2017 9 hours ago, Arizona Chris said: Looks like mississipian chert. The dotted lines are fan shaped bryozoans, this round object is a steinkern of a crinoid calyx, maybe abatocrinus? If you look closely around the steinkern, you can see the exterior mold of the outside of the calyx as bumpy. The thin gap in between is where the enclosing "shell" or calyx as it is called was before it was dissolved out. My guess. Also to the lower right of the calyx, those dark spots look to be dolorhombs. For those who may not know; there is little if any distinction between an internal mold and a steinkern. Link to comment Share on other sites More sharing options...
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