Photograph by James L. Amos The iconic arthropods of the Cambrian were the trilobites, which left a huge number of fossils. Trilobites had flattened, segmented, plated bodies that helped to ...

Helmetia expansa belongs to a rare group of early arthropods called concilitergans, close relatives of trilobites. Unlike trilobites, concilitergans lacked calcified exoskeletons, so their remains ...

This insight enabled him to use trilobites and other fossils to constrain the position of the continents throughout time. He has died, aged 79. Fortey was born in Ealing in west London and ...