Wednesday, January 20, 2010

Polychaete Annelid Worm

Hundreds of millions of years before the dinosaurs, there existed a ferocious creature. Terror filled victims lay in its path as it rampaged through a Paleozoic sea. Today all that is left is its jaws. Jaws that would rival later carnivores such as the Megalodon shark, Tyrannosaurus rex, and pit bull dogs (Canis familiaris). What beast could generate such carnage and fear? It turns out the polychaete annelid worm from the Ordovician Period. The annelid is a segmented protostome related to modern day leaches and earthworms.

Feast your eyes on such a destructive and potent weapons as these jaws.  Made of a of material so durable it almost appears made yesterday despite being over 400,000,000 years old.  The jaw consists of collagen (protein) fibers and traces of zinc.  Unlike the other fossils I collect that are molds in limestone or shale, or substitutions composed of quartz, calcite, aragonite (brown calcite?), or pyrite this material is apparently original.

Okay, I am exaggerating about this worm.  It appears to have eaten algae, plant leaves, and other worms. These jaws or scolecodonts were found in Ordovician limestone material from Kentucky.  A microscope was used to magnify the fossil at least 60 times its original size.  Very small but fun to find.

Thanks to Herb for the Ordovician gravel they were found in.

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