Trilobite pygidium from Rockport quarry Alpena.

[trilobites_are_awesome]

I went to Rockport quarry in Michigan several times this year. And found this trilobite. A friend says it looks like Crassiproetus but i am not sure....

 

Thanks! In advance

 

 

Edited November 9, 2023 by trilobites_are_awesome

[Fossildude19]

Need a picture. 

[trilobites_are_awesome]

1 minute ago, Fossildude19 said:

Need a picture. 

Sorry forgot.

[Fossildude19]

Any chance of teasing it out/uncovering a bit more? 

 

Also, a picture from directly above the trilobite would be helpful.

 

[trilobites_are_awesome]

5 minutes ago, Fossildude19 said:

Any chance of teasing it out/uncovering a bit more? 

 

Also, a picture from directly above the trilobite would be helpful.

 

I don't think so the shale is very fragile and so is the trilobite. Also they are very rare. I will try to get more pictures.

Edited November 9, 2023 by trilobites_are_awesome

[Kane]

Axis is too narrow for Crassiproetus. Possibly a Pseudodechenella.

[trilobites_are_awesome]

1 minute ago, Kane said:

Axis is too narrow for Crassiproetus. Possibly a Pseudodechenella.

It's flat Except for the middle lobe.

[trilobites_are_awesome]

More pictures.

 

 

 

[Fossildude19]

I'd be tempted to remove the rock covering the other half of the pygidium.

 

 

[Tidgy's Dad]

It's a risk, but I'd carefully whack it.

[trilobites_are_awesome]

I don't know if the rest of the pygidum is even there. @Fossildude19 why are there red lines?

 

[Kane]

30 minutes ago, trilobites_are_awesome said:

It's flat Except for the middle lobe.

I maintain my first identification . Tim's red lines indicate where you might carefully remove matrix with minimal damage to the specimen 

[Fossildude19]

I'd wager the rest of the pygidium is there.

If you were to use a dremel engraver with specialized tips, or, even a pin vise or exacto knife placed where the red lines are, you could "***GENTLY***" tap the matrix away from the fossil.

[piranha]

The Rockport Quarry Limestone does not have any trilobites.

 

As Kane stated, Pseudodechenlla is a better match from the Bell Shale or the Ferron Point Formation.

 

 

Ehlers, G.M., Kesling, R.V. 1970
Devonian Strata of Alpena and Presque Isle Counties, Michigan.

Michigan Basin Geological Society, Geological Society of America, 130 pp.  PDF LINK

 

Stumm, E.C. 1953
Trilobites of the Devonian Traverse Group of Michigan.
Contributions from the Museum of Paleontology, University of Michigan, 10(6):101-157  PDF LINK

[trilobites_are_awesome]

1 hour ago, piranha said:

The Rockport Quarry Limestone does not have any trilobites.

I have met two other people besides me who have found trilobites at Rockport in the black shale.

[piranha]

20 minutes ago, trilobites_are_awesome said:

I have met two other people besides me who have found trilobites at Rockport in the black shale.

 

The Rockport locality has trilobites....the "Rockport Quarry Limestone Formation" does not. This dechenellid originated from either the underlying Bell Shale or the overlying Ferron Point Formation. Additionally, Crassiproetus is absent from both.

[trilobites_are_awesome]

7 minutes ago, piranha said:

 

The Rockport locality has trilobites....the "Rockport Quarry Limestone Formation" does not. This dechenellid originated from either the underlying Bell Shale or the overlying Ferron Point Formation. Additionally, Crassiproetus is absent from both.

Thank you for the clarification. And thank you to all who helped ID it!