A new study has determined that many of Egypt’s pyramids contain hundreds of thousands of marine fossils, most of which are fully intact and preserved in the walls of the structures.

The study was carried out by researchers from the University of the Aegean and the University of Athens.

The researchers suggest that the stones that make up the examined monuments at Giza plateau, Fayum and Abydos must have been carved out of natural stone since they reveal what chunks of the sea floor must have looked like over 4,000 years ago, when the buildings were erected.

“The observed random emplacement and strictly homogenous distribution of the fossil shells within the whole rock is in harmony with their initial in situ setting in a fluidal sea bottom environment,” said Ioannis Liritzis, one of the researchers.

For the study, the researchers analyzed the mineralogy, as well as the chemical makeup and structure, of small material samples chiseled from the Sphinx Temple, the Osirion Shaft, the Valley Temple, Cheops, Khefren, Osirion at Abydos, the Temple of Seti I at Abydos and Qasr el-Sagha at Fayum.