Biomolecular zooarchaeology: revolutions in our understanding
To reconstruct how people lived in our deep past we are dependent on what survived underground for thousands of years. While organic material degrades heavily over time, archaeologists regularly recover large quantities of bone remains from their excavations, including from Stone Age (also known as Palaeolithic) contexts. Palaeolithic zooarchaeologists study each of these bone fragments individually, recording morphological characteristics, various measurements, and traces of use. However, both natural and human processes can break up these bones into small, unidentifiable fragments. Consequently, at many Palaeolithic sites we cannot identify which animal (or human) species these bone remains were from for 70-80% of the bone fragments.

Recent years have seen fundamental changes in how we can study these smaller, unidentifiable bone fragments. Thanks to recent advances in biomolecular methods, we can now taxonomically identify them by assessing variations in their proteome (for example by using Zooarchaeology by Mass Spectrometry (ZooMS) or Species by Proteome INvestigation (SPIN)). Further, we can gain direct insights into the age of these fragments through radiocarbon dates using tiny collagen samples.

We can also reconstruct past diet, environment and mobility by assessing a broad range of stable isotope ratios within these bone fragments (e.g. oxygen, nitrogen, carbon, zinc, strontium). Finally, we can reconstruct past animal and human populations by assessing ancient DNA from both bone and sediment samples.

In our recent paper in Nature Ecology and Evolution the well-preserved bone remains from the Palaeolithic site of Ilsenhöhle in Ranis provided a perfect case study to apply and integrate these different methodological advances, showing the truly remarkable potential of archaeological bone to revolutionise our understanding of past human lifeways.

Re-excavating the 8-metre deep Palaeolithic site of Ranis
The cave site of Ilsenhöhle in Ranis (Thuringia, Germany) sits at the base of a limestone rock beneath a fairytale Medieval castle. The site was already famous from excavations during the 1920s and 1930s by Werner M. Hülle. He uncovered a wealth of archaeological materials, including elaborately worked leaf-shaped stone points and a large collection of animal bones. The stone tools from Ranis have been described as having characteristics that are transitional between both Middle Palaeolithic (Neanderthal) and Upper Palaeolithic (Homo sapiens) tool types. This stone tool industry, known as the Lincombian-Ranisian-Jerzmanowician (LRJ), has been traced across central and northwest Europe, from Czechia and Poland, over Germany and Belgium, to the British Isles. Hülle did not identify any human remains from the LRJ layers at Ranis, and with poor bone preservation at many other LRJ sites, it remained heavily debated whether these tools were made by Neanderthals or early Homo sapiens.

An international research team led by Jean-Jacques Hublin (Max Planck Institute for Evolutionary Anthropology and Collège de France, Paris), Shannon McPherron (Max Planck Institute for Evolutionary Anthropology), Tim Schüler (Thüringisches Landesamt für Denkmalpflege und Archäologie) and Marcel Weiss (Friedrich-Alexander-Universität Erlangen-Nürnberg and Max Planck Institute for Evolutionary Anthropology) re-excavated Ranis between 2016-2022. The aims were to locate any remaining deposits from the 1930s excavation, clarify the stratigraphy and chronology of the site, and identify the makers of the LRJ. Excavating the site was logistically challenging, including the removal, by hand, of several huge rocks (from roof collapse events during the Palaeolithic) needing to be removed by hand, but this was rewarded by the discovery at nearly 8 metres depth of untouched archaeological material that could be linked to the LRJ technocomplex. 

Bone fragments as an untapped resource of behavioural information
Around 1,800  bone fragments were recovered from the new excavations. In a first step, these were all studied from a zooarchaeological and taphonomic perspective (Smith et al., 2024). A range of species were identified, including reindeer, bison, woolly rhinoceros, arctic fox, wolf and wolverine, suggesting an extremely cold environment. This was in line with the temperature estimates obtained from oxygen isotopes on horse teeth, illustrating sub-arctic climate conditions during the LRJ occupation at Ranis, similar to modern-day Scandinavia or Russia (Pederzani et al., 2024). While some bones had clear traces of being butchered by humans (see Fig. 3), a lot of the material showed tell-tale signs of being consumed by large carnivores (especially hyaenas). 

Heavy fragmentation meant that only around 10% of the LRJ bone material could be identified to a specific animal taxa or skeletal element. To increase this identification rate, we sampled all morphologically unidentifiable bone fragments (ca. 300) from the newly excavated LRJ layers for proteomic analyses, alongside ca. 1,000 bone fragments from the old 1930s excavations. It was a very welcome surprise when we identified human remains in both the old and new collections. This meant that, for the first time, human remains were securely identified from an LRJ context, and mtDNA analysis by Elena Zavala later identified them all as Homo sapiens (Mylopotamitaki et al., 2024).

Stable isotope data was extracted directly from these human remains, illustrating a diet based on large terrestrial herbivores, more similar to contemporary Neanderthals than to later Upper Palaeolithic Homo sapiens.

Palaeoprotemics also expanded our zooarchaeological dataset and we were able to compare our species identifications on bone with the range of taxa identified in ancient sediment DNA samples (asedDNA; DNA extracted from the soil at the site). We noticed an increase in carnivore DNA in layers associated with an increase in herbivore remains and carnivore-modified material. Also, in layers with high proportions of both cave bear bone remains and asedDNA we identified decreases in carnivore DNA.

Taken together, variations in animal identifications, modifications on the bone surfaces and asedDNA evidence suggest the cave at Ranis was used intermittently by denning hyaenas, hibernating cave bears, and small, pioneer groups of humans (Smith et al., 2024). 

The behaviour underlying the earliest incursions of Homo sapiens into northwest Europe
Our work marks a significant shift in our understanding of the initial incursions of Homo sapiens into Europe north of the Alps. We were able to show that Homo sapiens ventured into the north European plains already 47,500 years ago and were facing severely cold climatic conditions. Moving in small groups, they shared their environment and sites with large carnivores, like hyenas, and they manufactured elaborately crafted leaf-shaped stone tools.

The brief use of the Ranis cave by small groups of Homo sapiens contrasts with the contemporaneous evidence for a longer and more intensive presence of H. sapiens at Bacho Kiro Cave in Bulgaria. This shows that we are only at the beginning of understanding the settlement dynamics underlying the earliest dispersals of Homo sapiens into Europe.

With this new suite of analytical tools and the large amounts of bone material available to study, both from new excavations and old museum collections, we are only at the beginning of a new phase of archaeological research. The use of biomolecular methods in zooarchaeology has immense potential to provide further insights into the behaviour of our early ancestors and their interactions with contemporaneous groups of local Neanderthals. 

Our results from Ranis were published in three papers and the Ranis stone tools and bones are on public display in the museum at Burg Ranis and the Landesmuseum für Vorgeschichte Halle (Saale).

Mylopotamitaki, D. et al. 2024. Homo sapiens reached the higher latitudes of Europe by 45,000 years ago. Nature. https://doi.org/ 10.1038/s41586-023-06923-7.

Smith, G.M., et al. 2024. The ecology, subsistence and diet of ~45,000-year-old Homo Sapiens at Ilsenhöhle in Ranis, Germany. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-023-02303-6. 

Pederzani, S. et al. 2024. Stable isotopes show Homo sapiens dispersed into cold steppes ~45,000 years ago at Ilsenhöhle in Ranis, Germany. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-023-02318-z

We are extremely grateful to Marcel Weiss, Dorothea Mylopotamitaki, Virginie Sinet-Mathiot, Elena Zavala, Helen Fewlass, Sarah Pederzani, Shannon McPherron and Tim Schüler for their comments and suggestions on this post.  Header photo by Raija Katarina Heikkilä.