Glass Trilobites II - More examples from the Permian

[Arizona Chris]

Greetings all,

 

We finally finished our microscopic sorting from last weekends fossil adventure on the Highline Trail in the Permian Fort Apache Limestone.  The last batch from the acid pans had nearly no microfossils, but many well preserved larger "Macro-Micro" fossils.  Two new pygidiums preserved in silica were found, and something very new, we found FIVE free cheeks complete with eye cutouts and genial spines also preserved in silica!  These fossils are beautiful shiny and translucent examples of  a complete replacement of the trilobites molts in silica which is brown to caramel colored.  You might say its a pseudomorph of "silica after trilobite".    Im also getting a bit more experienced with the new microscope and stacking software.  I found as I suspected, you NEVER want to leave in the .5x reducer lens in front of the two objectives when doing imaging.  The addition of that lens causes noticeable astigmatism and chromatic aberration because it is by design ( and all stereo microscopes are made this way that use these auxiliary lenses) tilted at around 15 degrees with respect to the optical path.  A doubler lens would do the same thing.  These therefore are direct shots with no extra lenses at about 10x and are considerably sharper than previous attempts.  

 

First lets start with the new pygidium, a nice 4mm wide specimen attached to the back of a mollusk of Anisopyge:

(thats a toothpick holding up one side to make it level)

 

I got the focus stack to work great here - 11 parts using Picolay.  The depth of this one was so extreme, only a tiny area was in focus on one shot.  A straight pin is on the lower right for scale.

 

Three sets of left side free cheeks:

 

 

Two right side free cheeks.

 

Well thats todays post, Im continuing to refine my technique on the trinocular microscope images, and hope to share more of my experiences with all of you soon!  How do they look to you?

[ynot]

Looking great!

Nice job on those.

Looking forward to seeing the whole one that's hiding out there.

Tony

[Miocene_Mason]

Another one! Nice!

[FossilDAWG]

Excellent photography, and excellent work to find and recover such rare and fragile specimens.  

 

Don

[Arizona Chris]

Thanks - Were going to tackle the serpulids next, found gobs of them in the sediments.