Theisen Quarry

Bois d'Arc Formation

Quarry Access

As part of the fee, Leon will escort you to the quarry and provide assistance for the entire visit.
A gracious host, he willingly shares his knowledge and experience and will help in any way he can.

Theisen Quarry Face

The quarry was bulldozed a few years ago to open up the strata. Virtually all of the fossils are found on the surface
so the tool requirements are minimal. Knee pads are the most important tool of all!

If you find something that needs to be whacked or reduced, Leon is always there to help.

View of the strata

The quarry exposure is about 500 yards long. Several different strata are exposed on the quarry face.
Each of the different levels have slightly different compositions of fossils.

Quarry View

The Theisens are commercial fossil dealers so they will be hunting right along side you.
Leon is a fountain of information which he shares freely but don't expect that he's going to give you his best finds!

First Trilobite

I found this trilobite within a few minutes of arrival, laying in the road.
The enrolled Phacops are by far the predominant species, comprising about 90% of the trilobites.
Nearly all of the fossils here will require cleaning and preparation but the preservation is very good.

Embedded Phacops

Many of the extended Phacops specimens are found in the matrix. These are well preserved but will require prep.

Huntonia pygidium

Also, quite ubiquitous are the tails of Huntonia trilobites. Tails are everywhere in varying degrees of condition.
Complete Huntonia's are rather rare and are a noteworthy prize if you find one.

Complete Huntonia in a slab

I found this one on the first level above the road level. It appears to be complete under the matrix.

Close up of the Huntonia above

I will likely have this professionally prepared. A nice Huntonia was my goal for the venture and I
would hate to wreck it due to being a rookie preparator.

Some of the Phacopids, prepared

These are the first two trilobites that I have prepped. I am not a very experienced preparator so I chose some of the lesser
quality samples for practice. The quality of preservation is remarkable.


This is the first trilobite I found, as seen in the photos above.
I prepped this one myself.

Finished Huntonia Huntonensis

I sent this one back to Leon to have it prepped by the man himself.
It won "Fossil of the Month" on a the Fossil Forum website.

Prepped Phacopids

This is about half of the phacopids I found.
I still have at least 15 more to prep.

Cordania wessmani

This little trilobite is rather rare. Although not perfect, its a good representation.
I prepped it myself.

Dicranurus elegantus

I have not gotten the courage to start on this one yet.
I hope its a dandy under there!

Lots of Brachiopods

Although trilobites are the most desirable finds, there are lots of other fossils to collect.

I count at least 20 different species of brachiopods.

A sampling of the fauna of the Bois d'Arc Formation

In addition to trilobites, you can expect to find corals, bryozoans, nautiloids, crinoids and lots of brachiopods.

Leon's Contact Information: Oklahoma Trilobites

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