Modern microscopy technology has allowed two scorpion biologists, Carsten Kamenz of the Humboldt University in Berlin and Lorenzo Prendini of the American Museum of Natural History, to study and document what is nearly invisible. Looking at tiny morphological features like the sculpting of the hair-like outgrowths on lamellaestructures that fold like the leaves of a book and give the scorpion respiratory system its name, the book lungKamenz and Prendini found a wealth of new variation that gives insight into the evolutionary relationships among scorpions. Their research, recently published in the Bulletin of the American Museum of Natural History, presents their raw data as an illustrated atlas of the book lungs of all major lineages of scorpions.
"The richness of morphology is a vast and still largely unexplored source of data for understanding the evolutionary relationships among organisms," says Prendini, Associate Curator in the Division of Invertebrate Zoology at the Museum. "We have not learned all we can because the more we look at morphology, the more we find."
Kamenz and Prendini revisited book lung morphology for the first time since 1926 to assess whether these organs illuminate the scorpion tree of life. Book lungs allow some arachnids, including all scorpions, most spiders, and whip scorpions, to breathe air. Scorpions were traditionally placed at the base of the phylogenetic tree, as a sister group to all other arachnids, but molecular data has complicated this picture by suggesting that scorpions move higher on the tree, closer to sun spiders and daddy long legs. Consequently, the question of whether the book lung evolved once, at the base of the arachnid phylogenetic tree, or more than once, as arachnids adapted to life out of water, is unresolved.
This study is the most complete review of scorpion breathing apparatus ever: 200 specimens from 100 genera in 18 scorpion families were examined. This sample re
|Contact: Kristin Elise Phillips|
American Museum of Natural History