Found this odd concretion possibly a jellyfish. It was at washburne state park on oregon coast. It was in the sand mostly exposed thought it was trash at first a Frisbee or piece of styrofoam. But it's definitely stone, and was a week or two after our beaches were covered in a wash of jellyfish. No room to step between them even in most spots. This was found in the sand all the way at the back of the beach near the end of the sand that then hits the dune area and cliffs. I am wondering if it is of a jellyfish, maybe one that washed back further and stuck while the rest got swept back out?