It is now commonly accepted that hexapods emerged within the pancrustacean group that evolved on land [1, 5]. Since Collembola and other apterygotes, such as Protura, are at the base of the hexapods clade, it is often suggested that the collembolan divergence coincides with adaptation to diverse terrestrial ecosystems [15]. As such, they may provide key insights in the terrestrialization process of the hexapod animal clade. Collembolans most likely have an edaphic origin, and not an aquatic origin. However, several species of Collembola have a semi-aquatic lifestyle. These have to be considered as secondary adaptations among more derived Collembola [15]. The ancestral position of Collembola is confirmed by fossil evidence. The oldest hexapod fossil is the collembolan Rhyniella praecursor dated from the early Devonian, about 400 million years ago [16]. The estimated evolutionary distance between hexapods and crustaceans is 479 million years ago (Mya) and 406 Mya between springtails and insects