Some ammonites had long, straight shells, while others had helix-shaped shells. Most species, however, had coiled shells lined with progressively larger chambers separated by thin walls called septa.

Ammonites' growing shells typically formed into a flat spiral, known as a planispiral, although a variety of shapes did evolve over time. Shells could be a loose spiral or tightly curled with whorls ...

1. Research ammonites and find your favourite species. Ammonites came in a variety of shapes and sizes. Pay attention to features including shell shape, the presence of any ribs, and ornamentation ...

Lyme Regis Museum geologist Paddy Howe, who was a technical adviser for Ammonite, describes Anning ... it is the specimen used to describe this species and that scientists still refer to it ...

The new species appears to have lived roughly 72 ... He said he stumbled upon the fossil while searching for ammonite fossils for his doctoral thesis. “I have been researching fossils in the ...

Ammonite fossils, an example is shown here ... In this evolutionary tree, species A and B share a recent common ancestor. Species A is therefore most similar to species B. Species F and G also ...

Scientists estimate more than 99 per cent of all species that have ever existed ... The city’s first one was found in 1920; it was an ammonite, which is an extinct shelled sea creature that ...

Ammonite fossils, an example is shown here ... In this evolutionary tree, species A and B share a recent common ancestor. Species A is therefore most similar to species B. Species F and G also ...