Fossils of them are found all around the world, sometimes in very large concentrations ... also known as the true ammonites. These animals are known from the Jurassic Period, from about 200 million ...

Some ammonites had spines for defence and others would have had ornamentation that may have served to strengthen their shells. Around 180 million years ago in the Jurassic period, Dactylioceras lived ...

Mr Wonfor, who runs Wight Coast Fossils which provides guided tours on the island, said it's particularly rare to find an ammonite with ... for her discoveries in Jurassic marine fossil beds ...