Roasting turtles over fire drastically reduced processing effort and time tens of thousands of years ago

Prehistoric human communities that consumed turtles did not only benefit from a relatively easy prey to capture: cooking them over fire allowed them to optimise labour and drastically reduce the time needed to obtain meat. Roasting turtles directly on the embers could turn a long and demanding task into a quick and much more accessible process.

This is the main conclusion of an experimental study published in the journal Scientific Reports, led by Dr Mariana Nabais, researcher at the Centro de Arqueologia da Universidade de Lisboa-UNIARQ, with the participation of Dr Ruth Blasco, researcher at IPHES-CERCA, and Dr Anna Rufà, researcher at the Interdisciplinary Center for Archaeology and the Evolution of Human Behaviour (ICArEHB), Universidade do Algarve. The study analysed, under controlled conditions, the differences between processing raw and roasted turtles, both in terms of time and effort required and the marks these activities leave on bones.

The results are conclusive: while processing a raw turtle could take between 9 and 49 minutes, when roasted the time was reduced to just 5–7 minutes. Moreover, when raw, efficiency depends much more on each person’s skills and experience, whereas cooking makes the procedure faster and more uniform. This difference is far from anecdotal: it reinforces the role of fire as a decisive technology to optimise tasks, facilitate cooperation, and transform the organisation of daily activities among early human groups, beyond its use as a source of heat or protection.

Less force and less skill needed to access the meat

The study tested turtle butchery carried out by expert and non-expert experimenters, comparing how processing varies depending on whether the turtle is handled raw or after roasting it whole on embers. When raw, the task involves separating the carapace and plastron, disarticulating the limbs, and extracting tissues through a combination of cutting and percussion. It is a physically demanding and technically more complex process.

By contrast, when cooked, heat makes the carapace and plastron more fragile, softens tissues, and facilitates the separation of anatomical parts, simplifying the work and reducing the need to apply force. In some cases, processing raw turtles even caused fractures in the lithic tools used—an issue that practically disappears when specimens have been cooked.

One of the most relevant aspects is that roasting reduces reliance on experience. When raw, expert participants performed better in some phases of the process, whereas with cooked specimens the differences between experts and non-experts were noticeably reduced. This suggests that cooking could have enabled more individuals to take part in food preparation, with possible implications for labour organisation and skill transmission within the group.

Bone marks: a signature consistent with the archaeological record

In addition to measuring time and effort, the study analysed the marks left by processing on bones and shell plates. Raw-handled specimens show more cut marks and percussion evidence, while roasted specimens mainly display burning traces, as well as a different set of marks resulting from less aggressive processing.

This pattern matches what is observed at numerous Palaeolithic sites, especially in the Mediterranean region, where turtle remains often appear associated with hearths, showing evidence of exposure to fire and a reduced presence of cut marks. This reinforces the interpretation that roasting turtles may have been a recurring and culturally transmitted practice rather than occasional behaviour.

Fire as a driver of innovation and social change

The findings provide a renewed perspective on the impact of fire in human history. Beyond cooking to improve taste or digestibility, this technology made it possible to reduce energetic costs, simplify tasks, and manage time more efficiently in everyday activities.

In this sense, the authors note that turtle cooking may offer a privileged window into understanding how seemingly simple innovations influence behaviour: cooking helped transform resource exploitation and may have had direct implications for cooperation, planning, and the distribution of tasks within human groups.

Study reference

Nabais, M. et al. (2026). Experimental analysis of roasted and raw turtle butchery and implications for early human cognition and behaviour. Scientific Reports. DOI: 10.1038/s41598-025-31738-z