Bitubulites problematicus Blumenbach, 1803 and the cradle of ichnotaxonomy in central Germany

Ichnotaxonomy, the science of naming and classifying trace fossils, plays a pivotal role in palaeontology and sedimentology as a prerequisite to determine trace fossils and to utilise them for palaeoenvironmental interpretations. The roots of ichnotaxonomy can be traced back to the age of naturalists (18th century), when ichnological phenomena were described and interpreted in central Germany, long before ichnotaxa were validly introduced following Linnæus’s Systema Naturae (10th Edition, 1758) as the starting point of zoological nomenclature. The oldest valid ichnogenus name known till now was Asteriacites von Schlotheim, 1820 (resting trace), and others were introduced first from central Germany, such as Medusites Germar, 1827 (coprolite), Chirotherium Kaup, 1835 (vertebrate track) and Rhizocorallium Zenker, 1836 (burrow). The discovery of the holotype of the Lower Jurassic Bitubulites problematicus Blumenbach, 1803 in Berlin makes this nomen the oldest validly described ichnotaxon. It consists of a pair of tubes encased in a concretion, which is consistent with the diagnosis of Tisoa siphonalis de Serres, 1840, described from the Lower Jurassic of France decades later. Because B. problematicus became a forgotten name (nomen oblitum), T. siphonalis is defined as a nomen protectum and takes precedence over B. problematicus. This early and relatively high activity level in describing and interpreting trace fossils (although not necessarily seen as such), together with several validly introduced ichnotaxa long time before anywhere else, make central Germany the cradle of ichnotaxonomy.