Submitted on 2014-10-02 by David Thompson

Location (approximate): Alpena, Alpena, MI

Strat unit: Thunder Bay formation

Submitter notes: Two different sizes of the same species. The larger is in the previous photo, the small one is 3 cm thick by 5. cm wide.

Photo title: Big and small Megistocrinus nodosus

Taxa present: Megistocrinus nodosus

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Submitted on 2014-10-02 by David Thompson

Location (approximate): Alpena, Alpena, MI

Strat unit: Alpena formation

Submitter notes: This is a nice crown with the calyx 3.8 cm wide and 2.8 cm deep. The overall crown is 8.1 cm long with nice arm definition

Photo title: Crinoid crown

Taxa present: Pithocrinus cooperi

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Submitted on 2014-10-02 by David Thompson

Location (approximate): Milan, Washtenaw, MI

Strat unit: Silica formation

Submitter notes: This small Brachiopod has two inarticulates. This is the ventral (bottom) side with the scar of a Petrocrania species showing.

Photo title: Strophodonta brachiopod with two inarticulates!

Taxa present: Strophodonta demissa

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Submitted on 2014-10-02 by David Thompson

Location (approximate): Milan, Washtenaw, MI

Strat unit: Silica formation

Submitter notes: This is the brachial (top) valve with an intact Petrocrania hamiltonae snugly in place. It is unusual to have inarticulates on both valves of a brachiopod.

Photo title: The other side of the previous brachiopod

Taxa present: Strophodonta demissa

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Submitted on 2014-10-02 by David Thompson

Location (approximate): Milan, Washtenaw, MI

Strat unit: Silica formation

Submitter notes: A nice big articulate brachiopod that is 5.4 cm wide and 4.6 cm long. Just visible on the hinge line is an inarticulate brachiopod shown in the next picture.

Photo title: Large Brachiopod

Taxa present: Megastrophia concava

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Submitted on 2019-05-12 by David Thompson

Location (approximate): Alpena, Alpena, MI

Strat unit: Thunder Bay formation

Submitter notes: Contrast in size of blastoids from same formation.

Photo title: Small & large of same species.

Taxa present: Placoblastus obovastus

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Submitted on 2014-10-02 by David Thompson

Location (approximate): Milan, Washtenaw, MI

Strat unit: Silica formation

Submitter notes: These inarticulates, the largest being Petrocrania hamiltonae, and 1.5 cm, are out of the way at the back of the big Megastrophia. The tiny ones are .76 mm and are in the Philhedra family but they may be stewerti or crenistriata sp., it is hard to tell.

Photo title: Multiple Inarticulates hiding out on the hinge line.

Taxa present: Megastrophia concavus

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Submitted on 2019-05-12 by David Thompson

Location (approximate): Alpena, Alpena, MI

Strat unit: Thunder Bay formation

Submitter notes: details of Ambulacra

Photo title:

Taxa present: Placoblastus obovastus

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Submitted on 2015-04-03 by David Thompson

Location (approximate): Paulding, Paulding, OH

Strat unit: Silica formation

Submitter notes: Here is a very complete example of a Phillocarid mandible or Gastric tooth. These are attributed to the two largest species of Phillocarid, either Dithyrocaris or Herbertocaris. It isn't clear which. This very complete jaw or attachment structure is rarely preserved. The "teeth" are 3.5 cm or 1 inch long the matrix is 9.5 cm by 6 cm. collected by me on 6/28/14.

Photo title: Phillocarid "Mandible" & jaw,

Taxa present: Herbertocaris wideneri

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Submitted on 2016-06-08 by David Thompson

Location (approximate): Paulding, Paulding, OH

Strat unit: Dundee formation

Submitter notes: Collected at Paulding and prepped by Scott Vergiels.

Photo title: Dundee Limestone Rostroconch

Taxa present:

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Submitted on 2019-05-12 by David Thompson

Location (approximate): Antwerp, Paulding, OH

Strat unit: Dundee formation

Submitter notes: injured Rostroconch that healed and grew.

Photo title: Deformed Rostroconch

Taxa present: Conocardium coneus

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Submitted on 2021-08-16 by David Thompson

Location (approximate): Sylvania, Lucas, OH

Strat unit: Silica formation

Submitter notes: This plate from the Silica shale was collected long ago, but I have not been able to get anyone with skills needed to prepare it until now. It shows a complete Arthroacantha carpenteri crinoid crown with arms, caylx and stem plus a distinctive Bryozoan colony related to the Silica Fm., Sulcoreteporra deissi (Mc Nair 1937) Size of plate 9" or 23 cm wide by 8 1/2" or 21 cm. Weighs 8 .5 lbs.

Photo title: Silica Fossil plate

Taxa present: Arthroacantha carpenteri, Sulcoretepora deissi

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Submitted on 2021-08-16 by David Thompson

Location (approximate): Sylvania, Lucas, OH

Strat unit: Silica formation

Submitter notes: This entire plate was expertly prepared by J. Koniecki who is familiar with the Silica and took special care to reveal this Bryozoan colony on the plate.

Photo title: Detail of Bryozoan colony

Taxa present:

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Submitted on 2021-08-16 by David Thompson

Location (approximate): Sylvania, Lucas, OH

Strat unit: Silica formation

Submitter notes: Here is closer view of the crown showing charactoristic branching of arms and detail of stem column

Photo title: Detail of crinoid crown

Taxa present: Arthroacantha carpenteri

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