Professor Richard Fortey journeys high in the Rocky Mountains to explore a 520-million-year-old fossilised seabed containing bizarre and experimental lifeforms that have revolutionised our understanding about the beginnings of complex life. Among the amazing finds he uncovers are marine creatures with five eyes and a proboscis; filter-feeders shaped like tulips; worm-like scavengers covered in spikes but with no identifiable head or anus; and a metre-long predator resembling a giant shrimp.
