Orthoceros are a form of Marine Invertebrate. They are found in layers of marine rock. They had an interesting array of movement, utilising both swimming and crawling on the ocean floor - filling their shells with air so they could float and propel themselves by squirting jets of water. They date back to the Silurian Age (more than 400+ million years ago).
Ammonites are a Marine Invertebrate which is closely related to the octopus and squid. It is estimated that they became extinct some 66 million years ago and date back to the Devonian Age (some 400+ million years ago).
Height - Approx. 25 to 35cm