We thank the private collector M. Wulf, Rödelsee, who has contributed fossils from his collection to this investigation. Our thanks are also due to G. Schweigert, Stuttgart, who reviewed the manuscript and gave helpful comments. Moreover, he kindly provided access to material from the collection of the Staatliches Museum für Naturkunde, Stuttgart. Furthermore, we are very grateful to the Zentrale Einrichtung für Elektronenmikroskopie of the University of Ulm, especially to R. Weih, for running the EDX analysis and preparing the specimens prior to SEM observation. The radiology department at Safranberg, Ulm, is thanked for facilitating testing of the capacities of their medical X-ray CT scanner on the Antrimpos sp. specimen. Finally we thank all those involved in programming freely available software programs used in this research, i.e., GIMP, OsiriX, ImageJ, CombineZM and Structure from Motion (MeeSoft). J. Dunlop, Berlin, kindly improved the language of the manuscript. JTH is currently funded by the German Science Foundation (DFG) under WA-754/15-1.