One of the longest-ranging and outwardly primitive-looking groups of animals on the planet are the Medusozoa. In consisting of around 95% water, it may be surprising to know that there is a fossil record of jellyfish, however how does one differentiate their fossils from other abiotic sedimentary structures when both look like sub-spherical blobs?

In this episode we speak to Graham Young, Curator of Geology and Paleontology at The Manitoba Museum, Canada, who addressed the identification of jellyfish fossils in a recent paper Young & Hagadorn 2010 The fossil record of cnidarian medusae.