Deciphering the Evolutionary History of Hermit Crabs

Exceptionally preserved fossils provide invaluable insights into the history of life. Most such specimens are preserved in two dimensions; however, in rare cases, exceptionally preserved three-dimensional fossils can be found, revealing the morphology of extinct species in extraordinary detail. Here, we focus on one such specimen, an exceptionally preserved fossil hermit crab from the Cretaceous of Spain. This specimen retains poorly mineralized structures that have never previously been described in detail in extinct hermit crabs. Our aim is to study this fossil using synchrotron phase-contrast tomography, which is the optimal approach for resolving the internal structure of this unique specimen. The results will be used to reconstruct a three-dimensional digital model of the hermit crab fossil, which will form the basis for a phylogenetic analysis of modern and fossil species, thereby shedding new light on the evolutionary history of this important group.