A new group of juliform millipedes from the Age of the Dinosaurs
Object of research:
Millipedes, Bernstein, Diplopoda, Millipedes, Myanmar, Amber, Cretaceous
Although millipedes play, as one of the first groups of animals conquering land, a major role in terrestrial ecosystems since more than 400 Million years, the fossil record documenting their evolution and diversity is relatively scarce. This is especially true for the Age of the Dinosaurs, the Mesozoic, from which only slightly more than a dozen fossil forms are known. Burmesian amber from the late Cretaceous gives us insight into the diverse fauna that existed during the reign of the dinosaurs. With the help of micro-computer-tomography (µCT) we will describe an unknown group of extinct juliform millipedes, which cannot be assigned to any recent family.
Amber, fossilized tree resin, can preserve as a time-capsule the biodiversity of the past, allowing us to explore an ancient ecosystem. Burmesian amber formed about 100 million years ago, in forests covering the area today known as Myanmar. Although this amber is known to be exploited since over 2000 years, only recently the first species of millipede was described. During this project we will use modern µCT-technology and 3D-reconstructions to describe an unknown group of juliform millipede. Juliform millipedes share an elongated, cylindrical body with an enlarged collum (the first trunk-ring) and a similar composition of their defensive fluids. Our group varies from all today living groups by the absence of legs on the fourth body-ring. We suggest that this group could be a new family of the class Diplopoda. The structure of the gonopods, which can be explored using 3D reconstruction, suggests that they belong to the cambaloid millipedes, usually placed within the Spirostreptida. The cambaloids systematic remains chaotic and it is probably not a monophyletic group. We could already identify several specimens belonging to this group, which probably represent different species, based on morphological characters. The outstanding preservation of the specimens, generously lent to us by Patrick Müller, the largest European collector of arthropods preserved in Burmese amber, allows us to describe new species in the same way, we would describe extant species. Thanks to modern techniques we are able to reconstruct relevant morphological characters to clarify the identity and position of this new group of juliform millipedes.