Another Waldron Shale Mystery

[RCFossils]

I am hoping that someone might recognize what these two structures might be. They appear to me to be from some type of arthropod (probably trilobite).

Bothe are from the Silurian aged Waldron Shale.

Thanks,

Rob

[RCFossils]

This is the second item. My best guess is trilobite glabella.

[Caleb]

This is the second item. My best guess is trilobite glabella.

This is a hypostome from a lichid trilobite.

Edited March 4, 2011 by Caleb

[piranha]

The first posted images appear to be of a graptolite. One genus from IFNA on plate 22 numbers 15 & 16 are reminiscent of your fossil. I'm not sure which genus has current precedence, either Graptolithus or Retiolites recorded from the Silurian of Arkansas to New York.

Thoughts?

[Kentuckiana Mike]

The pictures in your first post remind me of a segment of the right lobe of Arctinurus trilobite. They are found in the Waldron Shale. I think it is turned over showing an underneath view.

Attached is a picture of several segments. Note how lobe segment has an indented crease down the middle with bumpy surface texture. It also has a long narrow leaf shape.

Well that's my guess.

[piranha]

The pictures in your first post remind me of a segment of the right lobe of Arctinurus trilobite. They are found in the Waldron Shale. I think it is turned over showing an underneath view.

Attached is a picture of several segments. Note how lobe segment has an indented crease down the middle with bumpy surface texture. It also has a long narrow leaf shape.

Well that's my guess.

Spectacular call Mike !!

I'm looking at plate 180 in Riccardo Levi-Setti's 2nd edition Trilobites. It's a Arctinurus occidentalis that is weathered and missing the integument around the entire margin of the bug. This reveals the ventral terracing lines that transverse the segments. Nice work with the clincher and thanks for the fresh look at it turning this one inside out and right side up for us.

Give the man a cigar !!

Trilobites - Levi-Setti 2nd ed. pl 180

[John Southard]

I am hoping that someone might recognize what these two structures might be. They appear to me to be from some type of arthropod (probably trilobite).

Bothe are from the Silurian aged Waldron Shale.

Thanks,

Rob

Wow Rob! Neat stuff and I love the shale these are preserved in. At first I couldn't help but wonder at the first of your images being perhaps some sort of Silurian worm? Then I couldn't get out of my head that it reminded me of something from the Burgess Shale. I know that this is a long shot but how about not a worm or a trilobite but Pikaia. I love the first of these pics below as it seems to show some sort of trilobite nearby that has some similarities to your second image. Food for thought.

Even Charles Wolcott was thinking worm when he looked at Pikaia. If Pikaia was to be the protochordate then some of them or something like them had to make it out of the Cambrian.

[RCFossils]

Thanks Caleb for the hypostome ID. That was my second guess and was pretty sure that whatever it was probably came from a lichid due to the size.

The second piece is also most likely off of a lichid. It could very well be from the tail of Arctinurus or possibly Metopolichas. I do have a tail of A. occidentalis that i collected from the Niagaran dolostone (also Silurian) in the Chicagoland area.

Here are a few pictures.