Cretaceous Diatoms from Marca Shale collected in Panoche Hills, California

[Michael K.]

Hello Bill,

These are very nice pictures of the diatoms. The pictures from yesterday are also interesting, although I have never seen one like the third one with the three thin spines. Perhaps this is a type of Odontella, but I am not sure.

I have not found an Entogoniopsis polycistinora yet either.

I will have to keep looking...

Best wishes
Michael

[Beatsy]

Hi everyone,

Found in a revisit of DOS 63 (a cleaning experiment). It's probably a well-known and common form, but it's the first time I've found one and I can't ID it. The centre is a small recessed dome and the outer ring of radiating pores is slightly raised in relation to that.

Any ideas? Thanks.

[bill2penn]

Hi Beats,
Perhaps Biddulphia lacunosa Long, Fuge and Smith, 1946.

Long, Fuge and Smith, 1946, p. 101; pi. 15, fig. 10

Bill

[Beatsy]

Hi Bill,

Thanks for looking.

I did look at that one but rejected it because it lacks the distinct wide ring of radiating pores around the central bump. It just didn't give me that "aha, I found it" feeling

It might be natural variation within the species though, but I have no idea how variable it could be as I only have the one specimen to compare. So far...

Cheers
Beats

[anne]

Hmmm, what about Metrosulus gracilis...
best
anne

[Beatsy]

Hmmm, what about Metrosulus gracilis...

Hello Anne,

You're right, that's the one! Thanks.

[bill2penn]

Here comes the sun!
Radiolarian from Marca shale. Inverted stacked image using Leitz Pl Apo 25X/0.65.

Bill

[Michael K.]

Yes it is an very interesting Radiolarian, like an Sponge.
I have never seen this bevore.

Greetings
Michael

[Michael K.]

Hallo zusammen,


Na, wer von Euch hat den Hut verloren?

---
Diese interessante Radiolarie? fand ich heute im Material. Wie meist auch als 3D Bild.
Um das so fotografieren zu können steht das Ding fast senkrecht. Ich musste es so positionieren
das der gebogene Rand zu sehen war. Da habe ich ca 15 Min. für gebraucht, bis ich es in der Position
hatte.


Gruss
Michael

[Michael K.]

Hallo zusammen,

Gestern habe ich mir auch noch eine andere eingebette Kittonia hannai mit dem 100er Objektiv angesehen.
Am Mikroskopkopf habe ich die Möglichkeit die "Vergrösserung" noch um 1,6 bzw 2,5 zu erhöhen.
Das Bild hier ist mit 2,5 entstanden.
Auch hier zeigen sich Scheibchen in der Mitte der Poren. Ich meine auch darin winzige Poren erahnen
zu können. Das sei aber zum Grossteil dem Rauschen und der zufälligen Anordnung geschuldet.


Gruss
Michael

[bill2penn]

Beautiful job Michael!!!

I show an image from a recent paper (https://doi.org/10.11646/phytotaxa.573.2.7) by Pat Sims and David Williams of the SEM of Kittonia hannai (hannae). It shows what you see!!
Bill

[Beatsy]

Hello Michael,

Nice job with the upscaled Kittonia pore details! Are you using white-light illumination? If so, you might squeeze a little more resolution with shorter wavelength blue light. Assuming you want to of course.

Here's some Kittonia elaborata pores done using 365nm UV light at 100x - just to show what's possible optically.



Cheers
Beats

[Michael K.]

Hello

The pictures were taken with a green filter.
It doesn't work for me with UV light. I bought a USB lamp with a gooseneck from Amazon for other purposes.
I tried it with that and nothing useful came out of it.
I have to look around for a UV light that would be suitable for my microscope. (Lomo, older "research microscope")

Greetings
Michael

[Michael K.]

Hallo Beats,

Thanks for sharing the picture. Have you inverted the picture and removed some of the noise? I just did it for myself on my PC. It's remarkable what comes out.

Regards
Michael

[Beatsy]

Hallo Beats,

Thanks for sharing the picture. Have you inverted the picture and removed some of the noise? I just did it for myself on my PC. It's remarkable what comes out.

No, I haven't done it for that picture. Post your version if you like.

Sorry for the confusion. I wasn't suggesting you use UV, just showing short wavelength improving resolution. However, a simple blue filter at 450nm wavelength will resolve more than a green one at 550nm wavelength.

Theoretically, the smallest resolvable distance with green light and an NA1.4 objective is ~240nm. Blue light with the same optics can get that down to 196nm.

So there is potentially still more to see/resolve with the setup you have. Assuming you have a blue filter. 

Cheers