Before preparation 1/2
Before preparation 2/2
The finished specimen
This fossil is a cranidium of an extremely rare trilobite. In fact this piece represents only the second specimen ever found of this species. Hoplolichas sterleyi was described 30 years ago on the basis of a much worse preserved find. This specimen unfortunately is not complete too, but all the better preserved. Due to the result of the painstaking preparation it was possible to describe the species anew, because the shell characteristics can be observed much better on this specimen.
At the beginning of the preparation, the significance of the specimen could hardly be guessed. The unprepared specimen strongly resembled H. tricuspidatus, the most common species of Hoplolichas found in glacial erratics of northern Germany. Only when it became visible on the anterior spines that they are curved backwards, the suspicion arose that it must be something much rarer. The preparation was very challenging due to the extremely spiny and tuberculated shell surface on the one hand and the very poor separation and hardness of the rock on the other hand. As an additional feature, the left spine exhibits a pathology. Healed spine injuries on trilobite cranidia are quite rare to observe.
Fossil: Hoplolichas sterleyi RUDOLPH 1990
Locality: Lubmin near Greifswald (Germany)
Formation: Upper Ordovician, Lower Caradoc, Kukruse stage C2-alpha
Width of the cranidium: ca. 5.4 cm (2.1 inches)
Work required: 22 hours
Collection: Tobias Surawski
The fossil was published in “Geschiebekunde aktuell”:
KRUEGER, H-H., SURAWSKI, T, ZWANZIG, M. (2022): Ergänzende Beschreibung der Art Hoplolichas sterleyi RUDOLPH, 1990 (Trilobita), in: GESCHIEBEKUNDE AKTUELL, 38. Jahrgang, Heft 2, S. 53-57. Link to the Gesellschaft für Geschiebekunde: https://www.geschiebekunde.de/