Weird Florissant Shale thing

[Earendil]

Hey everyone,

 

Asking about a piece of shale I just opened, there appears to be a little soft-bodied creature on it, however, it could just be an insect. The small piece measures exactly 1 and 3/8 of an inch. Is it a badly preserved beetle? Notice the small oval-shaped things lining the back. Thanks in advance for any help you can provide.

[jpc]

yes on the badly preserved part.  I don't think it can be IDed as detailed as a beetle.  The Florissant s full of insects of varying degrees of preservation, many of which leave a person saying "This might be an insect".  Others, though, are much more obviously insects.  

[Rockwood]

I wouldn't completely rule out this being a spider.  It may have a leggy look. 

[Fossildude19]

Cropped, enlarged, contrasted, and reversed, also. 

 

  

[Earendil]

Could it be something like this? Ostracods have been found there. Quoting the Florissant Fossil Beds National Monument Geologic Resources Evaluation Report,

 

"According to Meyer (2003), invertebrates other than insects and spiders at Florissant include a species of ostracod (Cypris florissantensis [mussel shrimp])" 

@LabRatKing, you're the freshwater expert. Does the above fossil look like an ostracod to you?

[jpc]

I would have to look through my Florissant fossils, but I think the ostracods are preserved as 3d oval shells, not carbon stains like the insects.  The fossil in question is a carbon stain (imprint).  

[Earendil]

13 minutes ago, jpc said:

I would have to look through my Florissant fossils, but I think the ostracods are preserved as 3d oval shells, not carbon stains like the insects.  The fossil in question is a carbon stain (imprint).  

Yeah, I noticed that after researching it a bit. I dunno, my instinct is just to say this is not a bug...

[Rockwood]

3 hours ago, jpc said:

I would have to look through my Florissant fossils, but I think the ostracods are preserved as 3d oval shells, not carbon stains like the insects.  The fossil in question is a carbon stain (imprint).  

Yes. They are nearly pristine looking.

[Rockwood]

Don't try this without a good second opinion. 

Maybe a quick drop of vinegar followed by a thorough rinse would uncover enough detail ?

[jpc]

I would try this on some other smudge that you don't mind losing if it fails.  

[LabRatKing]

On 1/20/2021 at 10:00 AM, yardrockpaleo said:

Could it be something like this? Ostracods have been found there. Quoting the Florissant Fossil Beds National Monument Geologic Resources Evaluation Report,

 

"According to Meyer (2003), invertebrates other than insects and spiders at Florissant include a species of ostracod (Cypris florissantensis [mussel shrimp])" 

@LabRatKing, you're the freshwater expert. Does the above fossil look like an ostracod to you?

It’s no ostracod fossil I’ve ever seen. I’d lean more towards a predaceous beetle larvae or hellgrammite. From the images and the scale, I’d lean towards a predacious beetle larva given what appears to be a well segmented thorax and lots of hard spiky parts...though some very careful prep might reveal more details for better diagnostics.

 

 

[Earendil]

On 1/21/2021 at 2:46 PM, LabRatKing said:

It’s no ostracod fossil I’ve ever seen. I’d lean more towards a predaceous beetle larvae or hellgrammite. From the images and the scale, I’d lean towards a predacious beetle larva given what appears to be a well segmented thorax and lots of hard spiky parts...though some very careful prep might reveal more details for better diagnostics.

 

 

Thanks, that sounds about right. So how exactly would you guys recommend prepping this? @Rockwood said a drop of vinegar and then a thorough rinse, any more tips?

[jpc]

I would personally leave it as is.  If you try to prep it, be prepared to completely obliterate it if the technique doesn't work.  Like I said earlier, practice on a less interesting specimen.  

Insects can be very difficult to prep and you would certainly need a microscope to work under.  I am not sure there is more of this thing to be found by prepping.   

[Top Trilo]

With the Florissant shale Ive seen you either have a good split or have to take off a few layers with a small blade. This one may just be poorly preserved. 

[Earendil]

Yeah, I think I'll leave it as is, labeled 'probable predaceous beetle larva'. I'm not sure there is more to prep either.

[LiasEpsilon]

That looks like a dragon- or damsel fly larva, though the shape reminds me more of an ant lion.

[Earendil]

On 4/9/2021 at 9:51 PM, LiasEpsilon said:

That looks like a dragon- or damsel fly larva, though the shape reminds me more of an ant lion.

Yeah, me too! Antlions have been found up there, but not the larvae. And I'd expect more prominent jaws.

[LabRatKing]

I’m still thinking along the lines of a predaceous diving beetle larvae:

 

 

then again, it could be a Reaper...

 

 

Edited April 29, 2021 by LabRatKing