Ediacaran biota represents an enigmatic evolutionary milestone in life’s history, yet the affinity of their characterized frondose organism remains rigorously unresolved, with hypotheses spanning protozoans, lichens, fungi, algae, placozoa, ctenophore, cnidarian, etc, based only upon superficial morphological similarity. However, the stalked Charniodiscus from Mistaken Point helps offer a rare opportunity for biomechanical analysis due to its diverse twisted forms. Numerical simulations reveal their predominant twisted form was a result of torsion due to the dynamic instability induced by fronds. Dimensional analysis maps this torsion to a biomechanical phase space, predicting a Young’s modulus range consistent with densely packed, aligned collagen fibers characteristic of eumetazoans. These findings suggest fronds lacked high water content or internal compartments, implying tissue-level complexity. These results also help refine the picture of their ecological roles. This proposed biomechanical paradigm would open a new window for understanding of tissues and evolutions of earliest complex animals.  

Computational Fluid Dynamics,Ediacaran,Frond,Earliest animal