The discovery of a rare “mud mummy” from ancient Egypt has surprised archaeologists, who weren’t expecting to find the deceased encased in a hardened mud shell.

The “mud carapace” is an unparalleled find; it reveals “a mortuary treatment not previously documented in the Egyptian archaeological record,” the researchers wrote in the study, published online Wednesday (Feb. 3) in the journal PLOS One.

It’s possible the “mud wrap” was used to stabilize the mummy after it was damaged, but the mud may have also been meant to emulate practices used by society’s elite, who were sometimes mummified with imported resin-based materials during a nearly 350-year period, from the late New Kingdom to the 21st Dynasty (about 1294 B.C. to 945 B.C.), the researchers said.

See Also:

The US Navy reportedly experimented with a “Spacetime Modification Weapon”…again

Dutch political leader Geert Wilders prosecuted by Turkey for “insulting Erdogan”

So, why was this individual covered with mud, rather than resin? “Mud is a more affordable material,” study lead researcher Karin Sowada, a research fellow in the Department of History and Archaeology at Macquarie University in Sydney, Australia, told Live Science in an email.

Read more: Live Science