Fossil of a Cretaceous fish preserved in chalk. The fish head and part of the body are articulated and it is possible to see just how large the orbit (eye) is in relation to the body with this fossil. These large eyes were probably needed to see in a dark environment found at depths of between 100m where the twilight zone begins, up to 4000m below sea level. Another possibility is that this fossil represents a juvenile fish. Juveniles have larger eyes relative to their body size than adults as eyes only function above a certain size.
This object is on display at RAMM in the Down to Earth gallery.