An Atlas of Book Lung Fine Structure in the Order Scorpiones (Arachnida)

Abstract

The fine structure of the book lungs of scorpions is diverse and phylogenetically informative, but has not been comprehensively investigated across the major lineages of the order. In this contribution, we present a fully illustrated atlas of the variation in book lung fine structure among 200 exemplars from 100 genera and 18 families of extant scorpions. We document variation in the surface sculpturing of the respiratory lamellae, the edges of the lamellae in the atrial chamber, and the posterior valvelike edges of the spiracles. These data provide insights into the phylogenetic relationships among Recent scorpions at several branches of the tree.