Lyropora sp. (comparison and discussion)

Ridenhower Formation, Paint Creek Group
Locality: Vogel School site, near Floraville, Illinois

Note: Often incorrectly referred to as the Paint Creek Formation
Paint Creek is the Group name
The city is often cited as Millstadt, Illinois
when in fact it should be Floraville, Illinois

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Lyropora sp.

Top row 2nd picture: The knobby feature on the right V point of the fossil
appeas to be a reaction to a parasite/predator attack.
A large close-up view of this featrue on this page: Click Here

These fossils illustrate both sides of the Lyropora

These 2 specimens (of different size) may be the same species but of a different age?

In life, fenestrate was attached to the opening between the "wings" like a web,
similar to the attachment of fenestrate on the screw-like axis of the bryozoan Archimedes.

Matrix: Limestone lens

The Ridenhower formation
is known for blastoids and the Lyropora is often overlooked.


The bryozoan genera Lyropora and Lyroporidra
(order Fenestrida, family Polyporidae) in Upper Mississippian
(Chesterian) rocks of eastern North America.
American Museum novitates ; no. 3111
McKinney, Frank K. (Frank Kenneth)
PDF link: Click Here
If the PDF is no longer available...Click Here

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