Diligent-Jackfruit45 t1_itowg7w wrote on October 25, 2022 at 6:08 AM

Reply to comment by IronSmithFE in How hard were ancient arthropod exoskeletons? by TrillCozbey

IIRC its not so much the rigid structure that determines the size of an insect but the fact that they rely on diffusion to oxygenate their cells. Get too big and the oxygen requirements of the creature grow too large to overcome without specialized organs like lungs.

IronSmithFE t1_itp0rkn wrote on October 25, 2022 at 7:06 AM

now that you mention this, he had stated something to that effect as well. of course, supposing a creature had only an exoskeleton but also had lungs, it still seems like it would be limited on size because of rigidity and weight.

the expert, i think, was arguing against the bugs in starship troopers as impossible creatures.