Fossil crinoids

Crinoids are echinoderms, such as starfish and sea urchins, which are also called sea lilies due to their characteristic shape. Exclusively marine, they live mostly anchored to the substrate by means of a long peduncle; they may have a flexible or rigid exoskeleton, cup-shaped and surrounded by several arms. In the Paleozoic they were particularly common and were inhabiting shallow waters, along with corals, sponges and algae (Giancarlo Ligabue Foundation Collection).