Even before Homo sapiens arrived in Sicily, some 16,000 years ago, hyenas of the genus Crocuta were widespread on the island.

One of the most iconic carnivores of the savannahs, the spotted hyena is present today in much of sub-Saharan Africa. However, during the Pleistocene, between 800 and 16 thousand years ago, it was widespread in much larger territories that included Europe and Asia, while the only island where the presence of this species has been documented by fossils is Sicily. This characteristic makes Sicilian hyenas unique from a palaeo-biological point of view. It offers scholars a rare opportunity to better understand both the adaptations and evolutionary processes linked to the geographical isolation of a large carnivore, which is extremely rare in insular contexts.

Thanks to recent advances in the study of ancient DNA, in recent years palaeo-geneticists have been able to analyse portions of DNA from some fossil hyenas, to date all from northern European sites or from northern Russia and China, where low temperatures favour the preservation of genetic material. In warm climate environments, such as the Mediterranean, DNA is more difficult to preserve in ancient remains.

In a recent study conducted by researchers from the Universities of Palermo, Milano Statale, Florence, Sapienza, Bangor University and Cambridge, published in the international journal Quaternary Science Reviews, the DNA of a fossil hyena from Sicily was analysed for the first time.

Nuclear DNA was successfully extracted from a fragment of coprolite, a fossilised hyena excrement more than 20,000 years old, from the San Teodoro Cave site (Messina, Sicily). The results of the analysis revealed that Sicilian hyenas possessed very special genetic characteristics, unique among all fossil hyenas whose DNA is known.

Giulio Catalano, first author of the study comments: 'Analyses suggest that the Sicilian hyenas belonged to a very ancient genetic group, distinct from today's African hyenas and peculiar to other fossil hyenas. This set of characteristics leads us to hypothesise that the population of these hyenas was once widely distributed across the continent, around 500,000 years ago. But having arrived in Sicily, thanks to geographical isolation, this population has preserved its genetic characteristics, while in the rest of Europe it has been lost over time. This is also thanks to the contribution of the various genetic exchanges that took place with African hyenas'.

'This type of analysis makes it possible to hypothesise that the Pleistocene hyenas of Sicily may be part of a 'relict' genetic population, which survived on the island up to around 20,000 years ago,' emphasises Raffaele Sardella of Sapienza's Department of Earth Sciences, who took part in the research.

Dawid A. Iurino, coauthor of the study, adds 'in addition to hyena DNA, we detected traces of equine DNA in the coprolite, which allowed us to reveal the contents of a 20,000-year-old hyena's meal. For palaeontologists and palaeogeneticists, the Mediterranean islands are like the Galapagos for Darwin! They represent an inexhaustible source of inspiration for new research and are the custodians of a geo-palaeontological heritage that must be preserved and enhanced, as it is unique'.

Luca Sineo, project leader, says: 'Grotta San Teodoro, with its enormous heritage, confirms itself as one of the most important European sites for the study of the Pleistocene, i.e. the last 2.5 million years. This research involved international scholars and was possible thanks to the collaboration with the Tindari Archaeological Park, the Proloco of Acquedolci, and the Messina Superintendence for Cultural and Environmental Heritage'.

'This study shows how, to date, technological development makes it possible to obtain genetic information even from complex biological substrates, such as coprolites,' explains Dr Alessandra Modi of the University of Florence, who participated in the research. 'Thanks to the large amount of data that can be obtained from an increasing number of remains belonging to different species, we are able to outline with high precision the evolutionary history not only of human beings, but of multiple living forms,' concludes David Caramelli, Professor of Anthropology at the University of Florence.

References:

Palaeogenomic data from a Late Pleistocene coprolite clarifies the phylogenetic position of Sicilian cave hyena - Catalano G., Iurino D.A., Modi A., Paijmans J.L.A., Sardella R., Sineo L., Caramelli D. and Barlow A. - Quaternary Science Reviews (2024) https://doi.org/10.1016/j.quascirev.2024.108859

Further Information

Raffaele Sardella 
Department of Earth Sciences
raffaele.sardella@uniroma1.it