Components of the newly-described Fezouata fauna. a, Demosponge Pirania auraeum b, Choiid demosponge c, Annelid worm d, Organism showing possible similarities to halkieriids e, Possible armoured lobopod f, Thelxiope-like arthropod g, Marrellomorph arthropod, probably belonging to the genus Furca h, Skaniid arthropod i, Spinose arthropod appendage

apparatus consisting of six overlapping elements. From Van Roy et al, 2010.

When the Cambrian period comes up in conversation, it is usually in reference to the evolutionary “explosion” which occurred around 530 million years ago. Animal fossils from before that time are typically small or are only traces, but in the latter half of the period (spanning ~488 to 542 million years ago) there is a dramatic increase in