The evolution of scorpions

[Halichoeres]

A new study uses the fossil record of scorpions in conjunction with molecular phylogenetics to estimate when and where scorpions originated and colonized land. The authors are circumspect about whether scorpions and other arachnids colonized land independently, or all derive from a common terrestrial ancestor. The recent paper in Systematic Biology finding horseshoe crabs nested within arachnids might have something to say about that. Regardless, this paper gives a nice overview of the fossil record of scorpions and gives a credible estimate of the age of the crown group (that is, the common ancestor of the living scorpions and all descendants of that ancestor, living or extinct).


The origin of the living scorpion radiation was late Carboniferous or early Permian, right as Pangaea was coming together. A convenient time to spread across land and maintain a nearly global distribution for 300 million years!

Paper (open access): https://link.springer.com/article/10.1007/s13127-019-00390-7