Researchers have identified a new genus of extinct gavial, Herugavialis cairensis, found in the same 45-million-year-old limestone used to construct the Great Sphinx of Giza.

A fossilized crocodilian discovered in Egypt’s Mokattam Formation has been reclassified as a new genus, Herugavialis cairensis. The specimen, which dates back approximately 45 million years, was found in the same limestone used to build the Great Sphinx of Giza. Researchers noted that the fossil shares a distinct physical trait with the famous monument: both are missing the tip of their snout or nose.

Reclassifying a Century-Old Discovery

The fossil skull was originally collected in the 1920s and was long classified as an extinct species of Tomistoma, a genus of gavial currently found in Southeast Asia. However, an international team led by Dr. Paul Burke of the Swedish Museum of Natural History revisited the specimen using modern analytical techniques. By employing 3-D X-ray and CT scanning methods to examine the internal brain and nasal cavities, the researchers identified significant structural differences between the fossil and known Tomistoma species. The team concluded that the fossil represents a unique branch of the gavial family tree. They named the new genus Herugavialis cairensis, honoring the Egyptian god Heru, who is associated with the Great Sphinx. The findings were published on October 7 in the journal Royal Society Open Science.

Evolutionary Context of Ancient Gavials

Gavials are a group of crocodilians known for their long, slender snouts and needlelike teeth. While only two species exist today in tropical Asia, the fossil record indicates that gavials once had a near-global distribution spanning over 100 million years. Many of these ancient species inhabited shallow marine environments, such as the Tethys Ocean that once covered parts of Egypt. According to the researchers, the region hosted a high diversity of gavials throughout the last 50 million years. This diversity fluctuated in response to global temperature and sea-level changes before the eventual disappearance of all crocodiles from the region. Herugavialis cairensis was one of at least three gavial species present in the area during that period.