Hello Fossil Forum!, I'm new here so I guess I'll just throw this one out. Found in Sand Springs (just outside of Tulsa, Northeastern Oklahoma) on the ancient Arkansas River (Mississippian/Pennsylvanian). http://www.ogs.ou.edu/StatemapOGQ/OGQ-79_Sand_Springs_24K.pdf I've been gradually exposing whatever these things are using light applications of heavily diluted muratic/hydrochloric acid and dishwashing soap gently lathered-in with a soft toothbrush. It's taken quite some time to get it to this phase of the "preparation"... but I'm curious, I'm seeing more than just one type of organism present on this piece. Could someone perhaps enlighten me with a dose of comprehensively accurate insight? I would be ever grateful as I value your thoughts. ~Noah Benzing