Scientists have used an innovative imaging technique to peer inside six 2,500-year-old animal coffins from Egypt—without opening or damaging them.
Using neutron tomography to non-invasively “see” through the metal boxes, researchers found the remains of lizards and bits of cloth that may have once been wrapped around their small bodies, they report Thursday in the journal Scientific Reports.
Neutron tomography involves sending beams of neutrons through an object to create a 2D or 3D image. Based on how the neutrons are scattered or absorbed, scientists can create an image of the organic matter inside. The technique is an increasingly useful, non-invasive tool for studying fragile, delicate and otherwise difficult-to-open objects from the past, such as an 800-year-old medieval pendant full of tiny bones.
In this case, scientists at the British Museum wanted to find out what was hidden inside six coffins in the museum’s collection—two that came from the ancient city of Tell el-Yehudiyeh, three discovered in Naukratis and two with unknown origins. All the coffins, also known as votive boxes, ranged from 2 to 12 inches in length.
Still-sealed and made of copper alloy, the coffins were topped with loops as well as eel, cobra and lizard figures that led researchers to believe they might find animal remains inside. At first, though, the team tried to use X-rays, but this failed to uncover much detail as the boxes were made of metal.
But with neutron tomography, the images revealed bones, bone fragments and an intact skull that likely belonged to lizards of the Mesalina genus, though researchers couldn’t determine the exact species.
Mesalina lizards are small reptiles that inhabit northern Africa; they’re often striped or spotted. They were likely mummified as part of “religious practices and beliefs that particularly thrived in the first millennium B.C.E.,” as study lead author Daniel O’Flynn, an X-ray imaging scientist at the British Museum, tells Newsweek’s Pandora Dewan. These animals were often believed to be incarnations of the gods or used as offerings.
“Lizards, like snakes and eels, were particularly associated with ancient Egyptian solar and creator gods such as Atum and Amun-Ra,” O’Flynn says to Newsweek.
The team also found lead inside some of the boxes, which was likely poured in while molten. Scientists suggest ancient Egyptians believed the metal had magical properties or, maybe more practically, would have made the figurine-adorned boxes less top-heavy. The molten lead might have also been used to make repairs or reinforce weak areas in the coffins.
Still, questions remain about how and why the creatures died. As O’Flynn tells Live Science’s Jennifer Nalewicki, it is possible ancient Egyptians sacrificed the lizards, but “they could also represent offerings to the gods.”
Regardless of what happened to the animals, the findings demonstrate the power and potential of neutron tomography to “shed light on the inner structure of complex archaeological objects, including their manufacturing techniques and contents,” as study co-author Anna Fedrigo, a researcher at the United Kingdom’s Science and Technology Facilities Council, says in a statement.