I have started this illustration after visiting Moscow Paleontological museum for sketching. I've made a sketch of young plesiosaur's skeleton cast, which one was suitable situated under the ceiling on the level of the second floor. For ammonite refecences I used an article of Aleksandr A. Mironenko "The soft-tissue attachment scars in Late Jurassic ammonites from Central Russia" which can be read here http://www.app.pan.pl/article/item/app000412013.html