Ancient Crocodile Species Discovered in Rocks Used to Build the Great Sphinx

Fossils recovered a century ago from the 45-million-year-old Mokattam Formation in Egypt have revealed a brand new species of ancient crocodile. The rocks, which were famously used to build the Great Sphinx, contained a remarkably preserved skull missing only the tip of its snout. Researchers have named the newly identified creature Herugavialis cairensis.

“Given this coincidence with the famously missing nose of the Great Sphinx, we decided to name the new crocodile after the Egyptian god Heru, who was possibly the inspiration for this iconic monument,” explained Prof Philip Mannion of University College London, who co-led the study published in the Royal Society Open Science journal.

Initially believed to belong to the Tomistoma schlegelii species of freshwater crocodiles, the fossil has now been officially reclassified thanks to modern analytical advances in palaeontology. By utilizing a CT scan to look inside the skull, an international team of researchers successfully identified several distinct anatomical differences that set the specimen apart.

The newly classified crocodile belongs to a group known as gavials, which today are found exclusively on the Indian subcontinent and in South-East Asia. However, the historical fossil record of gavials demonstrates a near-global distribution spanning more than 100 million years.

Herugavialis was not alone during its time in Egypt. The shallow marine environments that once covered much of the region were also home to at least two other species of gavials. “Throughout much of the last 50 million years, the Mediterranean region hosted a high diversity of crocodiles, including gavials,” said Dr Paul Burke, a researcher at the Swedish Museum of Natural History in Stockholm and lead author of the study. “However, this diversity fluctuated over time, seemingly corresponding to changes in global temperature and sea level, before the loss of all crocodiles in this region as a result of the drying of the Mediterranean approximately six million years ago.”

The Great Sphinx, featuring the head of a human and the body of a lion, rests on the west bank of the Nile in Giza. Sculpted from the limestone rock of the Mokattam Formation about 5,000 years ago, the monument stands 20 metres tall.