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The Mazon Creek fossil deposit has been compared to twinkies in the apocalypse in terms of preservation, according to fossil preservation expert and study co-author James Hagadorn, from the Denver Museum of Nature and Science. The most commonly found fossil is “the blob.” They are so commonly found that they are often sold cheaply in open public markets or discarded. The first detailed study of the collection was in 1976 and showed that out of 85,180 specimens, 42 % were just ‘blobs’. In 1979, professor Merril Foster of Bradley University looked through the recently classified specimens and determined them to be jellyfish of the Essexella asherae genus or medusae. It wasn’t until Roy Plotnik used modern taxon to reassess for a new comparison that it was recognized for its proper form: a sea anemone. More simply, he flipped the fossil upside down. Revealing a new, previously unseen, form. Thousands of specimens were examined from private collections and institutions such as the Field Museum, Yale Peabody Museum, Royal Ontario Museum, Manitoba Museum, and the University of Chicago. By comparing it to modern anemones, further analysis and morphological reconstructions, and the variable preservation factors, the morphology of the truncated distal end of the anemone displayed tube-like structures covered by a rugged bell-shaped umbrella-style curtain. This bell shape actually turned out to be the muscular foot used by sea anemones to wiggle and burrow along the seafloor, and the curtain was, in fact, the body of the anemone. Despite their ubiquitous nature 300 million years ago, their fossil assemblages are remarkably rare, even in the well-studied creek formation. While not quite as old as other formations, such as Chengjiang or the Cambrian Burgess Shale, it still has a lot of information to provide for future analyses.

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