Egypt’s Sphinx Stone Hid a Lost Crocodile

Researchers have identified Herugavialis cairensis, a new extinct gavial species from Egypt, from fossils first collected in the 1920s and later reassessed with CT scanning. The find links a 45-million-year-old shallow-sea predator to the limestone used for the Great Sphinx, while also illuminating the long decline of crocodile diversity in the Mediterranean.

A newly identified extinct crocodile from Egypt is drawing attention not only for its age, but for its uncanny connection to the Great Sphinx. Herugavialis cairensis lived about 45 million years ago in a warm, shallow sea that covered northern Egypt. Its fossils came from the Mokattam Formation, the same limestone later quarried to build the Sphinx. The animal is also missing the tip of its snout, echoing the monument’s famous missing nose and giving the discovery an unusually resonant cultural parallel.

The fossils were first recovered in the 1920s and originally assigned to Tomistoma, the genus of the living false gharial, because of their superficial resemblance. A new international study, published in Royal Society Open Science, used modern CT scanning to examine the nearly complete skull from the inside. Researchers from the U.K., Sweden, Germany, and Egypt found enough anatomical differences to separate the fossil from Tomistoma and establish a new species. The name Herugavialis honors the Egyptian god Heru, whom researchers say may have inspired the Sphinx.

The discovery also sharpens the broader story of gavials, the long-snouted crocodilians to which Herugavialis belonged. Today, only two species survive, both in freshwater habitats in South and Southeast Asia. Their fossil record, however, shows a once near-global distribution over more than 100 million years, including many species that lived in shallow marine settings. In Egypt, Herugavialis was not alone. The region’s ancient seas hosted at least two other gavial species, underscoring a much richer crocodile fauna than exists today.

Researchers say that diversity rose and fell with global temperature and sea level, before disappearing when the Mediterranean dried out about 6 million years ago. The new fossil therefore does more than add a species to the record. It captures a vanished ecosystem, shows how modern imaging can overturn old classifications, and highlights how environmental change reshaped one of the world’s most successful reptile lineages.