Archaeologists working near the site of an Iron Age home near Cambridge were perplexed when they discovered a large number of frog skeletons. Why more than 8,000 bones were piled up and preserved is a prehistoric mystery.
All were recovered from a single 14-meter-long ditch, right next to the site of an Iron Age roundabout on Bar Hill, where there was a settlement during the late and late Iron Age (400 BC). BC-43 AD). The discovery was made by the London Archaeological Museum (Mola) Headland Infrastructure, which carried out excavations as part of the road improvement scheme for the A14 national highways from Cambridge to Huntingdon.
While it’s not uncommon to find frog bones in ancient sites, archaeologists are baffled by the large number of bones discovered at Bar Hill.
Dr. Vicki Ewens, a senior archaeozoologist from Mola, a specialist in ancient animal bones, told the Observer: “In my experience, working mainly in places in London, we don’t have as many frogs. Having so many bones from one rasa is extraordinary “.
Zoo archaeologist Vicki Ewens analyzes the frog bones found at Bar Hill. Photo: © Mola / AndyChopping
Pointing out that these bones belong mainly to the common frog and the common toad, a species found in garden ponds across the country, he said: “We have also had possible evidence of a pool frog, which is exciting … No is something we usually find archaeologically.
“In my research, I only found two Saxon sites with only one bone in each. It’s a frog that was only found in East Anglia that became extinct in the 1990s, possibly due to habitat loss. but recently reintroduced “.
Because it is prehistory, it is difficult to find an explanation, although ancient civilizations — including the Egyptians, Mesopotamians, Greeks, and Romans — saw the frog as a symbol of fertility, among other associations.
Bar Hill
These amphibians are unlikely to have been eaten by people living in the settlement. Archaeologists say that although there is evidence of amphibian use in Britain dating back to the Stone Age, these bones have no cuts or burn marks. If the frogs had boiled, however, this might not have left a trace.
Evidence of charred grain found near the site suggests that its inhabitants were processing crops that would attract pests such as beetles and aphids, which are known to eat frogs. So perhaps the frogs were attracted to the area by the promise of food, archaeologists suggest.
Other possible explanations include “a prehistoric frog tragedy.” Archaeologists say that frogs are known to move in large numbers in the spring in search of breeding water and that they may have fallen into the ditch and become trapped.
According to one hypothesis, the unusual number of deaths could also have been caused by the hardships of winter. While winter frogs sometimes hide in the mud, extreme cold can kill them and they may have been the victims of a particularly severe winter.
Alternatively, they may have been ill, as in the 1980s, when frogs in the UK were devastated by a ranavirus.
It is not clear to what extent the ditch was. The field team dug about a meter of topsoil and subsoil to get there. Only small amounts of household waste were found at the site, which included fragments of Iron Age pottery.
Aerial view of the archeological site excavated at Bar Hill. Photo: © Mola / HeadlandInfrastructure
Amphibian bones were found among a large number of finds, from artifacts to human remains, during some 40 excavations that took place between 2016 and 2018 in an area of 234 hectares. Analyzes are still ongoing, although excavations have already been completed.
Ewens has spent the last two years studying the bones of animals, including livestock. Once all the studies have been put together, they are expected to shed new light on the lives of thousands of years ago and to discover the cause of death of so many amphibians.