Washington, April 26 : 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.
X-ray diffraction and radioactivity measurements, which can penetrate solid materials to help illuminate their composition, were carried out on the samples.
The analysis determined the primary building materials were "pinky" granites, black and white granites, sandstones and various types of limestones.
The latter was found to contain numerous shell fossils of "nummulites" gen. At Cheops alone, they constituted a proportion of up to 40 percent of the whole building stone rock.
Nummulites, meaning "little coins," are simple marine organisms.
Shells of those that lived during the Eocene period around 55.8 to 33.9 million years ago are most commonly found in Egyptian limestone. Fossils for the organisms have also been unearthed at other sites, such as in Turkey and throughout the Mediterranean.
When horizontally bisected, a nummulite appears as a perfect spiral. Since they were common in ancient Egypt, it's believed the shells were actually used as coins, perhaps explaining their name.
According to Robert Temple, co-director of the Project for Historical Dating, "Egyptian pyramid blocks of limestone tend to contain fossil shells and nummulites, often huge quantities of them, many of them intact, and many of them of surprisingly large size."
Fossils for ancient relatives to sand dollars, starfish and sea urchins were also detected in the Egyptian limestone.