Some showed slight damage near the feet, probably the result of ancient robbers rummaging for riches, experts said.
The coffins' exteriors were inscribed with verses and images from the ancient Egytpian Book of the Dead, which Salima Ikram, an Egyptologist at the American University in Cairo (AUC), said were standard decorations "to help you get from this world to the next."
Three of the coffins were wooden and lay parallel. A smaller fourth coffin—likely for a child—was made of papyrus or a similar material and was set at a slightly different angle.
The shared burial may have belonged to a single family, experts said, adding that it is uncommon to find coffins set at different orientations in this region.
Inside two of the coffins, mummies were covered at the head and feet with brightly colored cartonnage—a papier-mâché-like material often plastered over mummified bodies and decorated.
One of the mummies bore a cartonnage mask painted in gold, symbolizing eternity.
"It was a very sweet little mask," said Ikram, who x-rayed the mummies after the discovery.
In a nearby tomb, archaeologists found a completely intact mummified female—the first to have eluded generations of treasure hunters here.
The archaeologists said they plan to do more research, including facial reconstructions of the mummies, to determine their origins.
Thievery has damaged almost all the tombs in Deir el-Banat, making it hard for experts to know what the graves looked like in antiquity.
"The robbers come in regularly, so it is quite unusual to get intact burials," said Ikram of AUC.
As a measure of how widespread the crime is, the excavations even turned up some contemporary digging tools, which were probably stashed away by frightened thieves who left hastily.
The shallowness of the tombs—some of which are no more than a meter below the surface—makes them particularly attractive for looters.
"Robbers have always investigated cemeteries since the ancient times," Belova, the Russian archaeologist, said. "We have a lot of robbers who want to have a lot of gold."
The newly unearthed tombs may have been spared because of their relatively simple exteriors. Belova said her team had to rapidly document and remove the items because of security concerns.
She also said she hoped the discovery would change Deir el-Banat's reputation as a site that has been looted clean.
"It looks like a robbed area, but robbers cannot do a systematic study of a cemetery," she said. "That's why we still have a lot of chances to find something new here."
One of the strangest discoveries made at the site was the nonmummified body of a child buried with several mummified dogs.
The human remains, which were naturally mummified by the arid climate, were partially covered in a sack, its lower half surrounded by crudely mummified canines ranging from puppies to fully mature animals.
"They are put in any which way, with no real sense of orientation," said AUC's Ikram, an animal mummy expert.
Ancient Egyptians were known to keep domesticated pets and sometimes were buried with them.
(Read related story: "Mummy Birds Recovered From Egypt Factory" [August 9, 2007].)
Other animals were included in burials as part of a religious ritual, but this find is unlike any that has been documented, he said.
"The kind of deposit [of animals] you have here is neither like a sacred deposit [nor] like a pet deposit," Ikram said.
"It really is a very interesting new page in the archaeology of humans and animals in Egypt."
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