Leighton Formation Conodont?

[Mainefossils]

So, I have just found this highly-suspect fossil - my guess is a conodont. I saw it as I was examining pieces of shale, and thought it was worth looking at under the microscope. It seems to have the diagnostic features, even the transition of colors between the blue base and white tips. I was hoping for some of your options on it. 

 

If this is a conodont, it would be the first from this formation. My guess would be a Ozarkadina sp - it is a very common Silurian conodont here, and some of the elements look remarkably similar to my specimen. This specimen came from the very fossiliferous layers of this formation, and was found in association with multiple ostracod species (Kloedinia, Londinia, Hemsiella, etc.), T. elongatus tentaculites, and Nuculites corrugatus. This formation is Pridoli, Silurian. 

 

Thanks in advance for your help! 

 

Edited September 4, 2021 by Mainefossils

[Mainefossils]

I have researched each of the 35 species of Silurian conodonts found in Maine, and have found 3 possibilities - Aulacognathus kuehni, Ozarkodina confluens, and Spathognathodus. They each have problems with their bathymetry and sediment nature. I think that Spathognathodus is the best choice, based on the details I outline below. 

 

The first is the conodont species Aulacognathus kuehni. It is limited to deep water (BA 4-5) , while the bathymetry of the Leighton Formation is shallow (BA 1 - 2). Of course, the conodont element could have been washed in by the tide. Otherwise, the P2 element is very similar to my specimen. Below is the element I am talking about in figure 3 - the plate is from Bader, J. D (2007) Telychian (Llandovery, Silurian) Conodonts from the Chimneyhill Subgroup, West Carney Hunton Field, North-Central Oklahoma. 

 

                                                       

 

My next option was Ozarkodina confluens. The bathymetry is correct, but it is known from mixed sediments (siliciclastic and carbonate). It is a very common species in Maine, and the Pa element looks very similar to my specimen. Below is an image from a record I found of a Pa element, all the information on the specimen is here: https://geocollections.info/specimen/64793 

 

 

And my third and final conodont would be the genus Spathognathodus, a well-represented conodont - 8 Silurian species are found here. Many of the elements look almost identical to my specimen. The only problem with this identification is that all the Silurian species in Maine do not match my formation. They are either deepwater/carbonate, or deepwater/siliciclastic, or shallow/carbonate - while the Leighton formation was deposited in shallow water and is siliciclastic in nature. On the whole, though, I think that this genus would be the best identification for my specimen, mainly based on the element shape. Below are a few pictures of some elements from this genus, plate is from Merril, G. K. (1973) Pennsylvanian Nonplatform Conodont Genera, I: Spathognathodus. Journal of Vertebrate Paleontology, 47(2). 

 

                                                                   

 

Thanks for reading this everyone!  Thoughts? 

 

[tombk]

I can’t offer an opinion, not being familiar with such tiny specimens. It looks cool though. Nice find! And the photograph is quite clear. What instrument do you use to view and photograph at such a small scale?

[Rockwood]

[Mainefossils]

Thank you everyone! I'm glad you like it. 

 

@tombk, I use an Amscope compound trinocular microscope, with an Amscope FMA050 camera. With fossils such as these, I usually find the highest point of my specimen, and work my way down to the bottom of the specimen, taking pictures all along. By the time I get to the bottom, I usually have between 20 and 40 pictures. The specimen above took 36 separate images. 

 

Afterwards, I focus stack the images using a program called Affinity Photo. I also play with the brightness and contrast, the shadows and highlights, and the white balance to make the image look as natural as possible.

 

Below is a photo of the specimen after I prepped it - it has been heavily consolidated, due to its fragility. This unfortunately causes extra specular highlights and a slight blurriness in the picture. 

 

Thanks for reading everyone! 

 

 

[tombk]

I did not know there were so many stages  involved in getting a final photo of a microfossil. Your finished product looks great. Thanks for sharing your technique!

[Mainefossils]

My pleasure, thanks for your interest! 

[Fossildude19]

Excellent fossil!

I don't know much about them, but find them interesting, and am happy to see this posted here.  

[Mainefossils]

Okay everyone. I asked a Paleozoic conodont researcher on the genus of the conodont above. He said that it was a P2 element, but that multiple genera had similar element structure, and that he would not be able to identify it further. Therefore, I will identify my specimen as a P2 element of a Spathognathodus? for now - I hope that more diagnostic specimens will turn up. I will keep you all posted!