A centipede nymph in Baltic amber and a new approach to document amber fossils

The fossil record and especially examples of fossilized ontogeny have been described for many major arthropod taxa. However, little is yet known about ontogeny in fossil representatives of Myriapoda. Traditionally, taxonomy has focused on adult stages, and tends to overlook non-adults. Assigning an early stage to a specific species would demand having bridging juvenile stages. Additionally, as shown for other fossil arthropods, juvenile stages of a given species could have been recognized as separate species in the past. In this context, palaeo-evo-devo links evolutionary developmental knowledge with paleontological evidence. We report a nymphal lithobiomorph centipede from Baltic amber. The specimen was documented under cross-polarized light combined with image stacking. Stereo images were created based on these image stacks. Assessable characters are described and compared with data on extant lithobiomorph taxa. We conclude that the nymph (or larva) described here can be assigned to Lithobiidae and probably represents the fourth post-embryonic stadium. Findings such as that described here are still rare and detailed descriptions are not usually provided. The accessible data therefore represent an important example of fossilized ontogeny for centipedes.