Friday, June 7, 2019

What the heck is Lagerstatte?



When I first read about fossils found in ‘Lagerstatte’, I thought it was the name of a place or region, probably in Germany, that had a plethora of fossils residing there. Everything I assumed was pretty correct, except it’s not a place or region, it is a type of place. It turns out that in German, ‘lager’ means ‘storage’ and ‘statte’ means ‘place’. What this word indicates these days is a particular type of sedimentary deposit with fossils of exceptional preservation. I mean, sometimes even the soft tissue has been preserved, which is pretty darned exceptional.
This may have happened when a carcass was buried in an anoxic (without oxygen) environment with minimal bacteria, which would have delayed the decomposition of all biological features until a durable impression was created in the surrounding mud or whatever.
There are 2 types of Lagerstatte beds. The concentration type holds a lot of disarticulated hard parts, such as bones. Invariably, the accumulation of bones without a lot of other sediment takes time, so this type displays a large time period.
The 2nd type is conservation Lagerstatte, which hold exceptional preservation of fossilized organism or traces. Each of these sites can provide answers to important moment in the evolution and history of life. It’s like a snapshot, allowing the viewer to see the entire animal, even what the skin was like. Or the texture of a feather or shape of a footprint, in the case of a trace.
My first thought after reading about lagerstatte was that the now-fossilized creature must have fallen into water or mud, but there is oxygen in water (and thus in mud also), so that would not necessarily provide an anoxic condition. Still, there were places for them to land in order to be truly well-preserved.
Several types of inorganic replacement of the organic remains were mentioned in my reading; phosphorus, silica, pyrite (iron) and microbial mats. But in all these cases, this chemical change happened underwater. And if I read things rightly, under seawater.
The articles did have some pictures of these fossils, but they weren’t of T Rexes or stegosaurs, so I didn’t know what to look for. I gather that the large majority of these fossils are from way back when most creatures didn’t have bones, so they weren’t very large, and they hadn’t been well known before Lagerstatte beds were found.
I would have preferred to see one of these fossils first hand. Not to touch it, but when you have a picture, you can’t change the angle of how the light hits it and bounces into your eye. Sometimes just changing the angle a little can let you see details you otherwise wouldn’t notice. So I feel like having the item in front of me - even if in a display case - would let me study the tiny nuances that make these discoveries so exciting for those in the field.
Now, how could I use this knowledge in my writing? I don’t know. One of the beauties of writing fiction is that you get to use bits and pieces of knowledge in unimagined ways. So now that I have this knowledge, I can look for ways to use it.



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