This is my first post from a newbie.
I was hoping someone could help me and my grandson figure out what this is. It was found amongst gravel taken from the Missouri River and sold as landscaping gravel in Kansas City. If it is bone it appears to be fossilized as it sinks in water and has a 'clank" sound when tapped to metal or a tooth. Forgive the images as I used a 10 power loop held up to my phone camera to get the close ups. Also if anyone could make an ID on the black segmented stone used to prop up the specimen I would appreciate it. It was found in the same gravel.
Thanks So Much