Submitted on 2007-03-12 by John Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Arkona formation

Submitter notes: This crinoid named after a longtime collector from Thedford, Charlie Southworth, is very rare. The species was based on a single calyx that Charlie donated to a museum. This photo shows both a calyx and a small crown. The calyx measures 8mm in height and is 8mm wide at the base. The crown is 17mm high and 11mm wide.

Photo title: Rare Crinoid

Taxa present: Cadiscocrinus southworthi

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Submitted on 2007-03-12 by John Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Hungry Hollow formation

Submitter notes: These complete specimens were removed from the Hungry Hollow member in several pieces and then glued back together. The right side of the photo shows the base of each coral. The longer specimen measures 125mm. The shorter is about 75mm (not counting the bend). The diameters vary from 12 to 30 plus millimeters.

Photo title: Coral

Taxa present: Favosites (Emmonsia) arbuscula

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Submitted on 2007-03-12 by John Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Arkona formation

Submitter notes: This specimen of Decadocrinus exhibits a complete anal sac and a small portion of arms. This Genus also occurs in the Hungry Hollow and Thedford members of the Widder Formation. The partial crown measures 20mm high and 9mm wide.

Photo title: Crinoid on Matrix

Taxa present: Decadocrinus wrightae

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Submitted on 2007-03-12 by John Topor

Location (approximate): Arkona, Lambton, ON

Strat unit: Arkona formation

Submitter notes: Bryozoan colonies like this Leptotrypella become established on mature crinoidal lenses. Finding them relatively complete is a rare occurence. In most cases, they have to be reassembled. This colony measures 50mm by 30mm. The overall slab measures 75mm by 80mm.

Photo title: Bryozoan Colony

Taxa present: Leptotrypella quadrangularis

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Submitted on 2007-03-12 by John Topor

Location (approximate): Thedford, Lambton, ON

Strat unit: Widder formation

Submitter notes: Three weathered-out examples of this well-known, common brachiopod. In the photo, the top right and bottom specimens show the brachial valve view and the top left shows the pedicle valve view. The largest is 52mm long, and the smallest is 40mm in length.

Photo title: Brachiopods

Taxa present: Mucrospirifer thedfordensis

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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): 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 2007-03-09 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): 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): 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 2007-03-08 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 2007-03-08 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): 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): 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 2007-03-06 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 2007-03-06 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 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 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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