This is the "Fossil Friday" post #115. Expect this to be a somewhat regular feature of the website. We will post any fossil pictures you send in to [email protected]. Please include a short description or story. Check the #FossilFriday Twitter hash tag for contributions from around the world!
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For this weeks Fossil Friday, we have something different... very different. It's a Conulariid. It was found by Connor Puritz on the May 21st, 2022 ESCONI field trip to a Belvidere, IL quarry.
Conulariia are mystery animals. They are often classified with Cnidaria, but may represent a separate, extinct phylum. UCMP has a nice description of them.
Conulariids have been the subject of speculation for a century and a half. They aren't that uncommon; there are a number of genera, and they ranged from the Middle Ordovician to the Triassic. There are even a few cases in which conulariid soft parts have been preserved. Nonetheless, exactly what they were is still not settled. Because of their fourfold symmetry, they have often been placed in the Cnidaria by analogy with the fourfold Scyphozoa. However, their skeleton was very different from anything known in the Cnidaria, and they may represent a separate, extinct phylum, probably triploblastic (see Babcock 1991 for a defense of the separate phylum hypothesis, and Van Iten 1991 for a defense of the cnidarian hypothesis).
What can we say about conulariids? They had elongated, pyramidal exoskeletons, made up of rows of calcium phosphate rods. Most were square or rectangular in cross section, with prominent grooves at the corners. They lived attached to hard objects by a flexible stalk, and often lived in groups. Presumably they were filter feeders; how they reproduced is not known.
Thanks for the interesting contribution, Connor! These are fascinating animals and you have a very nice specimen! Connor has a nice field trip report over on the Fossil Forum.
