Dry Dredgers Field Trip
May 25, 2013

Mt. Orab, Ohio Trilobite Farm
Arnheim Formation

This field trip was brought to you by host Dan Cooper and field trip chair Bob Bross. Thanks Guys!

The Dry Dredgers met for this field trip at a pre-designated off-site location for two reasons. 1 - The dig site is on private land whose location needs to remain unpublished. 2- There is not enough parking on site so everyone must car pool to the site.

While waiting at the designated meeting place, members show off their fossil finds and share collecting information.  

Then Bob coordinated ride pooling for the caravan.

Bob  also worked on making sure everyone got parked successfully at the Mt. Orab site.

Dan Cooper presented an overview of the site - history, lay of the land and paleontology. Dan has joined with his sons to form the company Trilobites of America.

The Mt. Orab Ohio trilobite farm exposes the Arnheim formation of the Richmondian group. Heavy equipment was earlier used to expose the rich layer of the trilobite genera Flexicalymene and Isotelus. Dan has invited the Dry Dredgers to come to the site for surface collecting and limited digging.


Dan very generously handed out trilobite specimens he had found that day to the kids in attendance.

Fossils Found That Day

Trilobite Flexicalymene retrorsa


Trilobite Istotelus sp.

Pelecypods (clams)

Inarticulate Brachiopods

Pseudolingula brookvillensis

Articulate Brachiopods

A fragment of Vinlandostrophia sp.

Rafinesquina sp.


Mastigograptus strictus (next 2 pics)


Sinuites sp.

An internal mold of what is probably Paupospira sp.

Cyclonema sp.

Nautiloid Cephalopods

Ichnofossils (Trace Fossils)

Modern Analogs

Now let's see the June field trip to New York and Canada to collect trilobites and Eurypterids.

Here are the previous trips to Mt. Orab.

May 2012
May 2009
May 2005
May 2004

May 2003

May 2002

May 2001
Sept. 2000


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