Submitted on 2007-03-12 by John Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Arkona formation

Submitter notes: Pictured are five individual brachiopods. The top and the two left specimens show the brachial valve. The two brachiopods on the right show the pedicle valve view. They are a very common index fossil of the Arkona Formation. They were capable of living in the soft, muddy substrate. Most are flattened. These 3D specimens are uncommon in the formation. The five brachiopods range in size from 65 to 75 millimeters long.

Photo title: Brachiopods

Taxa present: Mucrospirifer arkonensis

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Submitted on 2007-03-12 by John Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Arkona formation

Submitter notes: The top specimen on this slab of two Mucrospirifers is in living position. The broken, dispersed shell material below the brachiopod allows for other animals to establish themselves on the muddy sea floor. The length of the brachiopod in living position is about 6cm.

Photo title: Brachiopod in Living Position

Taxa present: Mucrospirifer arkonensis

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Submitted on 2007-03-12 by John Topor

Location (approximate): Thedford, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: From the left in the photo, three different blastoid thecas showing the basal, side and summit views of the Genus, Devonoblastus. The height of these specimens ranges from 15 to 18 millimeters.

Photo title: Blastoid Theca

Taxa present: Devonoblastus whiteavesi

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Submitted on 2007-03-09 by David Thompson

Location (approximate): Alpena, Alpena, MI

Strat unit: Four Mile Dam formation

Submitter notes: This shows the tegmen of the previous Megistocrinus rugosus with the red replacement. Traces of red are found in fossils near the bioherms but rarely a complete calyx with this much. U.S. Ten Cent piece for scale

Photo title: The tegmen of 'red' crinoid

Taxa present: Megistocrinus rugosus

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Submitted on 2007-03-09 by David Thompson

Location (approximate): Alpena, Alpena, MI

Strat unit: Four Mile Dam formation

Submitter notes: This example of Megistocrinus rugosus crinoid caylx shows how at times mineral replacement can be of a rich red Calcite, making a nice fossil more attractive. This was collected at a bioherm or fossil 'reef' in a quarry. This shows the stem base, the upper tegman is complete also.

Photo title: A 'carnelian' crinoid from Alpena

Taxa present: Megistocrinus rugosus

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Submitted on 2007-03-09 by David Thompson

Location (approximate): Thedford, Lambton, ON

Strat unit: Widder formation

Submitter notes: Two different species of horn corals from Arkona & Thedford, Ontario that have the distinct 'scar' of attachment, the bottom valve of the inarticulate braciopod, Petrocrania hamiltoniae, clearly showing. The coral on the left is probablly Cystiphyllum sp.? while the one on the right is Heliophyllum halli. A U.S. Ten Cent piece is for scale. The top valve of the Inarticulate is missing showing the interior muscle scars.

Photo title: Horn Corals with inarticulate attachments

Taxa present: Heliophyllum halli, Petrocrania hamiltoniae, Cystiphyllum

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Submitted on 2007-03-09 by David Thompson

Location (approximate): Sylvania, Lucas, OH

Strat unit: Silica formation

Submitter notes: This Flexible crinoid from the Sylvania Silica formation is a good size for this species. These are not common. Ten Cent piece & fingers are for scale.

Photo title: Silica Crinoid

Taxa present: Eutaxocrinus wideneri

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Submitted on 2007-03-08 by David Thompson

Location (approximate): Milan, Washtenaw, MI

Strat unit: Silica formation

Submitter notes: This image compares the structure & size of Microcyclus thedfordensis with the small corals, Pleurodictyum (Procteria) cornu from the Michigan Silica formation. A. is an example of the Microcyclus from the Thedford area of Ontario, B. shows three examples of the Pleurodictyum, two with the upper multi-coralite side showing & the third showing the under side of another example. Unlike the Microcyclus, the Pleurodictyum does not start by attaching to anything. C. is a slightly larger example of the Pleurodictyum from the Bell Shale in Rockport, MI. Mike Toper has other examples on this site of Microcyclus. The U.S. ten cent piece is for scale.

Photo title: Tiny coralites

Taxa present: Microcyclus thedfordensis, Pleurodictyum (procteria) cornu

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Submitted on 2007-03-08 by David Thompson

Location (approximate): Milan, Washtenaw, MI

Strat unit: Silica formation

Submitter notes: This is another species of 'spirifer' Brachiopod from the Silica formation. This top view shows 4 inarticulate brachiopods, Petrocrania hamiltoniae, clustered on the top valve on one side only along with Aulopora corals. There is an additional inarticulate on the underside also which may indicate that this end was above the substrate and allowing the epifauna to live in this area.

Photo title: Spirifer Brachiopod with inarticulates

Taxa present: Mediospirifer audaculus, Petrocrania hamiltoniae, Aulopora

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Submitted on 2007-03-08 by David Thompson

Location (approximate): Thedford, Lambton, ON

Strat unit: Arkona formation

Submitter notes: Here is another example of the crinoid holdfast/anchor/grapnel, Ancyrocrinus bulbosus, from the Thedford area of Ontario. This is from the Arkona Shale at the Microcycus layer. What is unusual is the way I found these two parts. The grapnel with it's four arms was found in a wash area one year. I had the extrordinary good luck to find the stem piece the following year! This almost never happens especially with small fossils requiring you to look on hands & knees. What is even more extraordinary, I was able to actually recognize the connection & pick it up!

Photo title: Another Crinoid Grapnel

Taxa present: Ancyrocrinus bulbosus

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Submitted on 2007-03-08 by David Thompson

Location (approximate): Thedford, Lambton, ON

Strat unit: Arkona formation

Submitter notes: The two parts united for the complete holdfast.

Photo title: The parts together

Taxa present: Ancyrocrinus bulbosus

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Submitted on 2007-03-06 by Alex Fabian

Location (approximate): Alpena, Alpena, MI

Strat unit: Traverse formation

Submitter notes: A good Specimen measuring 4 cm

Photo title: Cephalopod

Taxa present: Tornoceras uniangulare

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Submitted on 2007-03-06 by Alex Fabian

Location (approximate): Alpena, Alpena, MI

Strat unit: Traverse formation

Submitter notes: Here is a colony of blastoids occuring on a small lense. The lense is composed of disarticulated blastoid brachioles and stems. This preservation is unique to the Givetian of the Great Lakes region. (aka Hyperoblastus cooperi)

Photo title: Blastoid Hyperoblastus americana (Barris, 1883)

Taxa present: Hyperoblastus americana

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Submitted on 2007-03-06 by Mike Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: Views of the pedicle and brachial valves of three different specimens of the species: The top row is one specimen with the valves separate, each showing internal structure. The bottom row is two different brachiopods with exterior views of the pedicle valve (left) and the brachial valve (right). The pedicle valve of the internal view is also on the left side of the photo. They are much larger than P. vanuxemi and common in the formation. The two specimens on the bottom row are approximately 8mm thick and 35mm wide x 36mm high.

Photo title: Brachiopod

Taxa present: Rhipidomella penelope

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Submitted on 2007-03-06 by Mike Topor

Location (approximate): Thedford, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: Views of the pedicle and brachial valves of two different specimens of the species. Rhipidomella vanuxemi is smaller than R. Penelope and not as common. The brachial valve is on the left and the pedicle valve on the right in the photo. These brachiopods are approximately 8mm thick. See scale in photo for size.

Photo title: Brachiopod

Taxa present: Rhipidomella vanuxemi

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Submitted on 2007-03-05 by Mike Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: Alveolites is common in the Hungry Hollow member. This distinct colony coral is disc-shaped. This specimen is large for the species. Generally, younger specimens will exhibit a smoother surface. This un-cleaned coral shows patches of shale on its surface. A tiny colony of Botryllopora socialis has made a home on the shale near the center of the colony. You will need to zoom in to see it. The coral measures 135mm x 115mm and is approximately 45mm thick.

Photo title: Colony Coral

Taxa present: Alveolites goldfussi, Botryllopora socialis

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Submitted on 2007-03-05 by Mike Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: This horn coral from the Hungry Hollow member is not common in the formation. This specimen is a very fine example. The coral is approximately 85mm long with a cup diameter of 45mm.

Photo title: Solitary Coral

Taxa present: Bethanyphyllum robustum

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Submitted on 2007-03-05 by Mike Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: The photo shows three different views of three specimens. On the left is the top view showing the tegmen, the center shows a side view of the plate ornamentation, and on the right shows the stem attachment area. Of all the crinoids that occur in the formation, your best chance is finding this Dolatocrinus sp. However, all crinoids in the Hungry Hollow member are rare. See scale in photo for size.

Photo title: Crinoid Calyxes

Taxa present: Dolatocrinus bulbaceous

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Submitted on 2007-03-05 by Mike Topor

Location (approximate): Thedford, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: Heliophyllum halli comprises the bulk of the solitary coral species found in the “coral zone” of the Hungry Hollow member. They are the most common coral to be found there. These two specimens are slightly smaller than average, but show the general form well. The diameter of the specimen on the left is 39mm. The length of the coral on the right is 67mm and the width is 42mm.

Photo title:

Taxa present: Heliophyllum halli

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Submitted on 2007-03-05 by Mike Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Arkona formation

Submitter notes: A partial crown from the Arkona fm. Surrounded by stem fragments of the same species. Extremely rare! See scale in photo for size.

Photo title: Crinoid

Taxa present: Melocrinus

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