THE FOSSIL OF THE DAY: PHYLUM BRYOZOA
 
Bryozoans are colony or mass animals. They start as plankton; when a larva finds a place to settle down, on what the textbook refers to as "a firm substrate," it buds off its own buddies, new individuals that form the colony. Sometimes the colonies look like lace fans, though there are many species and many different forms. The ones that form latticelike sheets with a single layer of zooecia (the colonial buddies) on each side belong to Order Cryptostomata, and the lacy fan or funnel shaped colonies are of the genus Fenestella. Alas, Fenestella was one of the genera wiped out in the great Permian extinction, about 248 million years ago. The fossils pictured and are at least 40 million years older than that, and I believe them to be examples of Fenestella.
I have found fragments of Fenestella at sites all over Tulsa County. Often little fragments are mixed in the "substrate" with pieces of crinoids, brachiopods, rugose sponges and what all else. Stone soup. Petrified Bouillabaisse. It would be something quite extraordinary to find a complete or near complete Fenestella fan colony.
Next: Back to Tall Chief?
9:56:54 PM 
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