The century-long fight over how turtles evolved to have shells


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The bit about the underside forming a shell first is interesting–I would not have guessed that. I can see the argument for stabilizing the body to help with digging, but I wonder if there was a parallel advantage in mobility (sliding through or sledding over sand/soil) as well?


Here is a charming story of how the turtle got his shell:


If the plastron benefited mobility then that sort of kills the basis for the theory of turtles developing the carapace for additional protection due to reduced mobility.


Turtles are clockwork entities, devised by James Blaylock as part of the backstory of The Digging Leviathan, only to be released into the environment when anti-steampunk extremists broke into his laboratory.


Russell’s Second Conjecture, that “It’s turtles all the way down”, has only been demonstrated for the first 107 turtles. It has been shown to be mathematically equivalent to the Riemann Hypothesis, so if a tortoise or terrapin is found, the corollary follows that there must be a corresponding non-trivial zero of the Zeta Function with a real part ≠ ½.

Both conjectures are equivalent to Dunsany’s Recursive Theology, which states that it’s chess-playing gods all the way up.


This video is a good example of why I love PBS Eons - There’s been a tendency with a lot of the other youtube science shows I’ve watched to cover things I already know about and only rarely surprise me. I often watched them for simpler ways to explain things I already knew, or to remember them for later when I might want to tell someone else about a topic and don’t have time to re-explain the basics. Eons consistently brings up stuff I just straight up did not know. Like what order turtle shell bits evolved in.


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