Nummulites build the stone of the pyramids
Coin-sized single-celled organisms accumulate into limestone that will later be quarried for Giza.
- When
- —
- Duration
- 10 million years
- Known to
- ± 4 million years
- Era
- Eocene, Cenozoic
Nummulites are foraminifera that grow to several centimetres — enormous for single cells — and in the warm shallow Tethys they are so abundant that their shells form limestone beds tens of metres thick across North Africa, the Middle East and southern Europe. Herodotus, seeing the discs weathering out of the blocks of the Giza pyramids, took them for petrified lentils left by the workmen. The rock is Eocene, the pyramids are 4,500 years old, and the misidentification is one of the earliest recorded attempts to explain a fossil.