Archaeologists have described the contents of six sealed ancient Egyptian animal coffins.
The mummification of animals was a widespread practice in ancient Egypt and previous research has suggested some mummified animals were believed to be physical incarnations of deities.
Others may have represented offerings to deities or have been used in ritual performances.
After previous attempts study the coffins with X-rays failed, Daniel O’Flynn of the British Museum and colleagues used neutron tomography – a technique that creates images of objects based on the extent to which neutrons emitted by a source can pass through them – to examine the contents.
Using the non-invasive technique, they found that all of the coffins are made of copper compounds.
The authors wrote: “The findings demonstrate the effectiveness of neutron tomography for the study of mummified remains inside sealed metal containers, and give evidence linking the animal figures represented on top of votive boxes to the concealed remains.”
According to the researchers, it is rare for such coffins to still be sealed.
Three of the coffins, topped with lizard and eel figures as well as loops, have been dated to between 500 and 300 BCE and were discovered in the ancient city of Naukratis.
A fourth coffin, topped by a lizard figure, has been dated to between 664 and 332 BCE and was discovered in the ancient city of Tell el-Yehudiyeh.
The two other coffins, which were topped with part-eel, part-cobra figures with human heads, have been dated to between approximately 650 and 250 BCE and are of unknown origin.
There was also evidence of broken-down bones in a further two coffins.
Textile fragments – possibly made of linen which was commonly used in Ancient Egyptian mummification – were identified in three coffins.
The researchers suggest linen may have been wrapped around the animals before they were placed in the coffins.
Further, they discovered lead within the three coffins without loops, which they suggest may have been used to aid weight distribution within two of them and to repair a hole found in the other.
Past research has suggested lead was used in love charms and curses, and the scientists therefore speculate the metal may have been selected due to this magical status.
The study, published in Scientific Reports, also suggested the loops on the other three coffins may have been used to hand lighter coffins from shrine or temple walls or from statues or boats used during religious processions.