Found these pieces in some grey cretaceous mix in Dallas. They were all in the same spot....as I dug one out I saw another and another, etc. I'm guessing they are Plesiosaur vertebra? They are small pieces (indicated by ruler). All pieces together are around 5 inches long. Would these be from a juvenile or are they from an dadult part of the body? The pics show all the pieces together and then various angles of individual pieces. Any help is appreciated. thanks, Jeff