This is a selection of specimens from the Early Ordovician (ca 488–472million years ago) Fezouata Biota of southeastern Morocco.

The fossils are preserved in iron oxyhydroxides after early diagenetic pyrite and tiny limonitized framboids are scattered in the mudstone. Some elements of the fauna are comparable with that of the Middle Cambrian Burgess Shale (sponges, marellomorphs, anomalocaridids), whereas others (starfish, horseshoe crabs, graptolites) are new.

I put this group together in late 2007 and early 2008, starting with the beautiful xiphosuran, which was the first example of this form I had come across (and still, 13 years later, the best individual example I have seen).