Traces or perforations caused by living organisms after the animal's death can be found on various dinosaur bone remains. These perforations, known as bioerosion structures, provide information that helps us understand the relationships between living organisms in the past, reconstruct palaeoecosystems and improve our understanding of the fossilization process. Now, a study published in the journal Earth-Science Reviews has identified this type of perforation in bones and, for the first time, also in pieces of dermal armour (osteoderms) from titanosaurs at the Lo Hueco site (Cuenca), dating from the Late Cretaceous.
The results indicate that the titanosaur carcasses from Lo Hueco were not rapidly buried, as had previously been suggested, but remained exposed long enough to allow specialized insects (mainly necrophages and saprophages) to bore into them. The study revises the palaeoecological reconstruction of the Late Cretaceous at the Lo Hueco site, offering a new interpretation of its sedimentary, ecological and environmental dynamics.
Furthermore, the study shows that a detailed ichnological analysis - that is, of fossilised traces or footprints - of bioerosion structures at sites with abundant preserved skeletal remains could be very useful for gaining a precise understanding of the process by which the remains accumulated and the palaeoenvironmental conditions under which this occurred.
In addition to expanding the fossil record of insect-induced bioerosion in dinosaur fossils, thanks to the exceptional preservation of the Lo Hueco site, the study has helped to consolidate the validity of the ichnogenus Cubiculum (which includes the identified perforations). Specifically, this ichnogenus is characterized by boreholes with a hemispherical or pouch-like shape which, when compared with modern analogues, have been attributed to the bioerosive activity of dermestid beetles.
The study is led by Professor Zain Belaústegui, from the Faculty of Earth Sciences and the Biodiversity Research Institute (IRBio) at the University of Barcelona. The study also involves experts from the National University of Distance Education (UNED), which leads the national research project that has funded this study, as well as forensic entomologists from the University of Alcalá (UAH).
A site rich in titanosaur fossils
At the Lo Hueco site, one of the most important in the European Late Cretaceous, there are not only more or less isolated bone remains, but also relatively complete skeletons of large titanosaur sauropods that lived 70 million years ago.
