The specimen is from a young female that lived in the early Oligocene, a period of global cooling, volcanic eruptions and seismic disturbance, driven by the collision of the Indian and Asian continental plates. The skull, from a species known as Aegyptopithecus zeuxis, or dawn ape, is the most complete and well-preserved known and only the second to be found.

Researchers led by the Egyptian Geological Museum in Cairo uncovered the fossilised remains in a quarry on the outskirts of the city and were able to perform detailed x-ray scans of the skull, revealing the size and shape of the brain.

The skull was half the size of the first dawn ape skull, a male found in 1966, suggesting modern apes and monkeys developed larger brains later in evolution.