SEM findings

I spent some more time in the SEM lab looking at some fossils I bought on the internet. The Trilobyte was an early arthropod that lived during the Middle Cambrian period in our Earth's history, roughly 570,000,000 years ago. The Horseshoe crab is an arthropod from the Phanerozoic period (just after the Cambrian period) that, after 300,000,000 years, is still in existence today.I wanted to see if the structural systems of prehistoric arthropods were similar to the modern day arthropods I've been researching. To determine this, I looked at sections of Trilobyte fossils and the shell of a modern era horseshoe crab in hopes of finding similarities to my current image collection.



The results were fascinating.

The horseshoe crab information will be shared Monday. The Trilobyte fossils showed an eerily evident similarity to the current specimens in terms of structural assembly. The layered assembly is most evident. The reticulating lattice argument is more speculative, but there is certainly strong evidence to suggest that the structural assembly of prehistoric arthropods was nearly identical to the assemblies today.

And now, the images:


Trilobyte "A":








The first sample had some good examples of the layered assembly. Though it is still rather speculative, the fact that these are not images of a rock but rather an animals fossilized shell leads me to believe in the legitimacy of this argument. The same assembly exists. Perhaps the most important thing to consider about the first specimen is that the layers occur in the same regular pattern and at the same scale as the layers in the modern day specimens Ive looked at. This might not be mere coincidence.




Trilobyte "B":







The second specimen showed fossilized forms strikingly similar to the ones in my current natural models. The layered assembly can still be clearly seen, but the striated lattice remnants are what pop out the most. Compare the first image in the "Trilobyte 'B' "section images to the below images of the crab specimens I've already looked at. Pay particular attention to the center of the mentioned Trilobyte image, as it shows a fragmented section of a layer with clearly defined and fossilized vertical structural members.The sections show similar assemblies.


fiddler crab images: