Scientists have identified an anemone whose fossils were mistaken for a jellyfish for years. Reported by the University of Illinois.
The studied remains come from the Mason Creek bed in the United States. The ancient river delta created ideal conditions to protect the soft tissues of many invertebrates by burying them in muddy sediments. The most common fossil in Mason Creek is the so-called “drop”. Such drops were so common and often unidentifiable that many were thrown away or sold for a few dollars at local flea markets. In the 1970s and ’80s, scientists concluded they were jellyfish and named them. Essexella asherae. These jellyfish are claimed to have a unique feature that no other living jellyfish has – a rigid “curtain” hanging from the umbrella-shaped “bell” at the top of the jellyfish – explains their barrel shape, like a skirt covering their tentacles.
Now Roy Plotnick and his colleagues have done further research and concluded that identifying these animals as jellyfish was a mistake. They mentally overturned the find, then everything fell into place: it looked like an anemone buried in the seabed. The “bell” was actually an enlarged muscular leg hooked to the base. The barrel-shaped body of the sea anemone turned into a rigid “veil”.
“While most of these fossils are preserved as decaying patches on the pavement that look like a used piece of gum, some specimens are so perfectly preserved that we can even see the muscles anemones use to flex and contract their bodies,” the scientists wrote. problem. .
The researchers noted that the large external diversity of specimens Essexella was related to the variable length of time that dead anemones stay on the seafloor before being buried in silt. At the same time, this sea anemone was not a hunter, but a scavenger, unlike many modern species.
ancient scientists said It’s about the evolution of the “airy” bones that made dinosaurs giants.