Dry Dredgers Field Trip
April 29, 2006
Brookville, Indiana
Arnheim, Waynesville and Liberty Formations, Late Ordovician Period

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Inarticulate Brachiopods

All of the previous pictures were of Articulate Brachiopods. There were a number of kinds of Inarticulate Brachiopods found that day too. 

Here's a beautiful specimen of Trematis.

This next picture is also Trematis, but shows the flatter specimen. 

Here's a close-up of the above Trematis (below).
 

Another, more common genera of Inarticulate Brachiopod found was Petrocrania. In the next 3 pics, they are found encrusting the Brachiopod, Rafinesquina. In this first picture, we see Petrocrania encrusting a Petrocrania, encrusting a Rafinesquina! The game begins. How many layers of Petrocrania encrusting Petrocrania can YOU find????
 
Notice in the Petrocrania above, the amorphous inarticulate was taking on the ridge pattern of it's host brachiopod.

Crinoids

No crinoid calyxes were found that day, at least that I know about. But here's a nice crinoid holdfast, called Lichenocrinus found that day.  (The second photo is a close-up of the same specimen.)
 

Next Page: Corals Found That Day