Thread by @Yara_Haridy

ITS OUT!✨

WE DISCOVERED A NEW WAY TO IMAGE FOSSIL CELL SPACES!

Yes, that spinning cell space is 400 mill-years-old, also turns out fossil fish gave us bone metabolism!

PhD chapter 1 is out:bit.ly/2PoUY3J

If you share ANY of my stuff on this site, share THIS THREAD!

This is my first ALL FISH paper.. what have I become?!

For the quick land well written lowdown check out the @Natgeo article by @Laelaps with bomb art by @BrianEngh_Art: nationalgeographic.com/science/articl…

For the continued ramblings of an overly excited scientist READ ON!

Again the paper can be found here @ScienceAdvances: advances.sciencemag.org/content/7/14/e…

OKAY lets get into it. My goal here is that you don't have to read the paper if you get through this.

So I don't know if you noticed but I think bones are interesting. Duh.

But whats even more interesting is what its made of!
The cells and the minerals.

I WANT TO UNDERSTAND OLD CELLS

First lets get a hold of what cells we'll be talking about.

Bone is made up by a few kinds of cells but we will focus on the BEST KIND. Osteocytes the ones that LIVE in the bone. They live in these caves called lacunae.

Art by: Dave Mazierski

So in fossils these cells don't survive. But their caves, their lacunae do! The lacunae are like a perfect mold of what the cell would look like.

In fact these lacunae are so perfect that we can use them to estimate genome size!

Palaeontologists usually use histology, SEM or more recently Micro-CT to image these cells.

And for a long time this served us well. But I needed more detail, the questions I had concerned how these cells talk to one another.

Histology wasn't working for me because its a complex 3D system and 2D wasn't going to cut it.

and CT scanning often gave me images that looked like this. Which is fine if you want to only count cells.

At this point I was sweating my PhD relied on this, but maybe we didn't have the technology yet

This same week I visited the @HZBde for an unrelated project and saw a poster one of our collaborators had. It had amazing images of a method I had never seen. It looked like cells..

The images were of battery corrosion tests ( like the ones below) My collaborators are amazing material scientists, and listened to me ramble and freak out alot so they didn't get what my excitement was about.

I asked them what scale this was at, and what they needed to run this.

I got an answer like "well it can't have too much water in it and has to be stable and not blow up please" I said hey.. fossils are pretty damn stable.

CAN WE TRY IT PRETTY PLLLEASE?!

They said yes. I held my breath.

They zapped my fossil. So this method uses an Ion beam and an SEM in unison where the ion beam shaves off some fossil, and the SEM scans the surface, and basically it is serial sectioning the fossil at a CELLULAR SCALE.

My AMAZING Co-first author Markus Osenberg sent me some images a few months later.

I straight up didn't believe him. I thought he made them in blender. I called him up and was like. wut. WHAT?!

HOW IT STARTED HOW ITS GOING

Okay okay.. so now we know we can do this.

THESE CELLS ARE REAL.

What can we do with this new toy?

Well turns out I didn't get to really make this choice, the first cells we got had a halo around them.

An intriguing halo. labeled here as "area of low density"

I FREAKED OUT.

this doesn't look like much, but know when you study a specific thing and it shows up on the test. SAME FEELING.

I had seen this before. IN HUMANS!!?

This is evidence of a process called

✨OSTEOCYTIC OSTEOLYSIS✨

A process where these cells dissolve the bone around them to release it back into the blood stream. this is how we humans and many other vertebrates regulate our mineral levels.

PLEASE SEE FULL SCREEN.

SO!!!!! we could see evidence of this process in fossil cells spaces. Here is the kicker: we were zapping the earliest vertebrates with bone cells. Early armoured fish.

This means this type of metabolism is ANCIENT!

The specimen we sampled was from a group of early armoured fish, they were the first that we know of to have osteocytes. Everything before had bones with not cells in them. SO WHY EVOLVE OSTEOCYTES?!

It is thought that maybe Osteocytes evolved because these fish needed more minerals accessible in a more efficient fashion.

This is not my hypothesis it has been floated my times before, and even recently by @DonaldDavesne! BUT NOW WE HAVE EVIDENCE!

TLDR;
1- New study applies new tech to give the best images of fossil cell spaces
2- also discovers earliest osteocytes could metabolize bone like modern ones do.

But please read we worked so hard 🤓🥺

So there is a lot more in this paper, like we applied machine learning to segment the cells.

We also applied network analyses to figure out which cells are talking to which! Here we see that some cells (in red) are more central to local connections than others.

We also figured out that at least in our placoderm sample the osteocytes branch about the same number of times as human osteocytes do!

But this is all preliminary as this is a sample of one.

THERE IS SO MUCH MORE TO SAY.. but I said it all in the paper.. its short and its OPEN ACCESS SO GO READ IT PLEASE!

advances.sciencemag.org/content/7/14/e…

Finally Ill leave you with
1-My co-authors are awesome! ALL OF THEM made this possible. There was much SciComm between the paleo and non-paleos This was truly an interdisciplinary effort. So I guess what Im trying to say is keep preaching fossils to your non-paleo colleagues.

2- I cannot wait to see how this will be applied to
-Fossil embryos
-Fossil teeth
-Invert fossils
-Plant structures
-Fossil feathers

AND THINGS I CAN'T EVEN THINK OF!

IM SO EXCITED TO HAND THIS TOOL OVER TO PALEO!

P.S.
From her on out placoderms are known as #BeetleMermaids. Not up for debate.

Art:@BrianEngh_Art