Animal Remains Analysis: Sources and Climate Information from Fauna

A single deer jawbone lying in an excavation trench does not look like much. But to a zooarchaeologist, that jawbone can point to the season hunters camped at the site, whether the animal was wild or already under human control, and what the surrounding landscape looked like thousands of years ago. Faunal remains, the bones, teeth, shells, and other hard tissues recovered from dig sites, are among the richest sources of environmental evidence available to archaeologists. This post looks at where these remains come from, what they reveal about past life, and how the study of decay and preservation, called taphonomy, helps researchers separate genuine climate signals from noise.

Where faunal remains come from 🔗

Animal bodies are made of both hard and soft tissue, but only the hard, mineralised parts usually survive burial. Zooarchaeological assemblages are typically made up of bone, teeth, antler, shell, and scales, while soft parts such as hair, skin, and muscle only survive in unusual conditions like waterlogged bogs or extremely dry caves. Each of these hard tissues preserves a different kind of information, so archaeologists rarely rely on one material alone.

Bone: the most abundant record 🔗

Bone is by far the most common faunal find at any site. Skeletal analysis lets researchers identify the species present, estimate the age and sex of the animal, and spot signs of disease or injury on the skeleton. Faunal analysts at excavation labs use this kind of skeletal comparison to work out what people ate, and where and how they obtained their food, simply by matching archaeological bone fragments against modern reference collections of known age and size.

Teeth: small structures, precise dates 🔗

Teeth are tougher than bone because enamel has a higher mineral content, so they often survive when other skeletal parts do not. Dental wear patterns give a rough age estimate, but the more precise method is counting growth layers in the cementum, the tissue that anchors a tooth root. These layers form in alternating bands tied to seasonal growth, so cementum analysis can reveal both the age at death and the season in which an animal died. This is one reason teeth are treated as small time capsules in faunal studies.

Antler, horn and ivory 🔗

Antlers are shed and regrown on an annual cycle in most species, so their presence or absence at a site can hint at the season of occupation. They were also functional raw material. Antler, along with bone and shell, was frequently shaped into tools and ornaments, and cut, scrape, and polish marks on these pieces reveal how they were worked. Horn and ivory, though less commonly preserved, add further detail on species identification and, in some contexts, long-distance trade or exchange.

Shell, scale and other remains 🔗

Mollusc shells, fish scales, and even eggshell survive well in specific settings and are especially useful for reconstructing aquatic and coastal environments. Because different shellfish and fish species tolerate different water temperatures, salinity, and flow conditions, their presence in a layer can indicate whether a river, lake, or coastline nearby was warmer, cooler, wetter, or drier at the time of deposition.

What faunal analysis reveals about the past 🔗

Once remains are identified, the real analytical work begins. Faunal assemblages are studied for cut marks, chop marks, and fracture patterns that show how an animal was killed and butchered, and how tools were used to process the carcass. Researchers also calculate how many individual animals are represented in an assemblage and estimate how much of the group’s diet came from meat versus other food sources.

Age, sex, and hunting patterns 🔗

The ratio of adult to juvenile animals, and male to female animals, in a faunal assemblage says a lot about hunting strategy. A cluster of young animals might point to a specific breeding season being targeted, while skewed sex ratios can suggest selective hunting or, later in prehistory, the early stages of herd management. Sex can sometimes be read directly from the skeleton, since the size and shape of horns and antlers can differ enough between males and females to separate them in an assemblage.

Domestication and tool use 🔗

Faunal remains also record the long transition from hunting wild animals to keeping domesticated ones. Selective breeding changes bone size, shape, and density over generations, and these changes are visible in the zooarchaeological record as a population moves from wild to managed herds. Alongside this, cut marks and butchery patterns show which tools were used and how consistently, offering a window into technological change over time.

Index fossils and dating 🔗

Some animal species are so closely tied to a particular time period or climatic regime that their presence works almost like a stamp. Zooarchaeologists call these index fossils, since finding them in a layer helps date that layer and infer the climate conditions the animal needed to survive. This is one of the strongest links between faunal analysis and climate reconstruction, because a shift in species composition through a stratigraphic sequence often mirrors a real shift in temperature, rainfall, or vegetation.

Taphonomy: reading what happened after death 🔗

Not every bone at a site survives, and fewer still survive intact. Taphonomy is the study of the biological, chemical, and physical processes that act on an organism after death, right up to the point it is excavated. It matters because separating patterns caused by human behaviour from patterns caused by natural processes is the first step in interpreting any archaeological assemblage accurately.

From death to burial 🔗

The first stage after death is usually the loss of soft tissue through scavenging or microbial decay. What happens next depends heavily on the surrounding environment. Bone and tooth material, made up of both mineral and organic components, survives best in alkaline to pH-neutral soils, and in anaerobic or desiccated conditions, while acidic, oxygen-rich, or repeatedly wet-and-dry environments tend to destroy it. This is why remains from arid caves or waterlogged, oxygen-poor sites tend to be so much better preserved than remains from open, seasonally wet ground.

Trace fossils and site formation 🔗

Taphonomy is not only about what remains, it is also about what those remains, and the marks around them, reveal about the site itself. Cut marks, footprints, burrows, dens, and nests are all forms of trace evidence that help reconstruct how a site was formed and used. According to Smithsonian taphonomy research, taphonomic processes are not just a source of loss but also a source of valuable information, since they reveal interactions between species and environments that would otherwise leave no trace in the fossil record. Reading these clues correctly is what allows a faunal assemblage to be trusted as climate evidence rather than dismissed as a jumble of scattered bone.

From bones to climate: putting the picture together 🔗

Faunal and taphonomic evidence become genuinely powerful when they are read together across a stratigraphic sequence. A shift from cold-adapted species to warm-adapted ones moving up through layers at a site can mark a real climatic transition, and the taphonomic condition of the bones, whether they are worn, mineralised, or fresh, helps confirm whether that shift is genuine or an artefact of mixing and disturbance.

India offers a well-documented example of this approach. Faunal assemblages from the Narmada valley in central India, associated with the Middle to Late Pleistocene hominin site at Hathnora, include species such as hippopotamus, wild horse, and wild pig. Researchers studying this material found that the recovered bone assemblage, including evidence of iron impregnation, points to warm climatic conditions that supported the hominin population during that period. This kind of species-by-species, layer-by-layer analysis is exactly how faunal remains move from being a curiosity in a museum drawer to becoming direct evidence for the climate of a vanished landscape.

What do you think? 🔗

What do you think? If a site gave you a mix of well-preserved bone and heavily weathered, fragmented bone in the same layer, how would you decide whether that mix reflects real seasonal hunting patterns or simply uneven preservation? And do you think index fossils are reliable enough on their own to date a layer, or should they always be checked against other evidence like sediment and pollen data?

References

1. https://textbooks.whatcom.edu/tracesarchaeology/chapter/__ancientfoodways__/
2. https://www.uwlax.edu/mvac/process-of-archaeology/lab-analysis/faunal-analysis/
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC12111438/
4. https://pressbooks.pub/guidetoarchaeology/chapter/__ancientfoodways__/
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC9068891/
6. https://orca.cardiff.ac.uk/id/eprint/123808/1/Baker%20and%20Worley_Animal%20Bones%20and%20Archaeology%20Handbook.pdf
7. https://repository.si.edu/bitstreams/c2474480-068e-4881-a956-2c6ef8a67f71/download
8. https://www.sciencedirect.com/science/article/abs/pii/S1871174X0800022X