Living Serpulid worm from Canada
Microconchid worm tubes from the Permian Fort Apache Limestone East of Payson
 

Updated  10/2/17
 

 Over two dozen microconchid tubes have been found so far in the acid fines from the second site we have found in the Fort Apache Limestone. Microconchids have been around since the Ordovician and are indeed a very ancient lineage. These worms build small coiled tubes attached to either hard surfaces such as shells or other small invertebrate hard parts, or on the leaves of sea weeds. We have found both types in this formation. They are small, barely visible to the naked eye, yet their coiled tubes are very diagnostic when sorting the silicified remains under magnification. Here are a few of the better preserved specimens found from about 35 pounds of rock from the latest locality east of Payson.

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 Section of spiny Urchin spine, with three serpulids attached permanently. This view shows the coiled tube on the lower left corner. 10x view.
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Side view of flattened spine, showing two more. Flattening occurs when the sediment containing the fossils are compacted before lithification.
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 A collection of pinhead sized spirals. Most of them are worm tubes, however two of them (right of center and lower left) are most likely juvinile nautiloids. Microconchids would have lived on the bottom of the leaves of sea weeds and when the weed died, the serpulid tubes fall to the bottom to be fossilized. Seen here at 7x magnification. The head of a straight pin is just below.
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 Close up at 45x of the tube spiral that is at the bottom of the above image. You can clearly see the opening coiling over the top of the earlier tube dwelling. It is preserved in nearly pure silica.
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 Bottom side of same specimen, 45x. Note how it is flat - this is the side that attached to the sea weed and grew against it. The microconchid essentially glued itself on to the leaf, forming a flat on the weed side.

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