A new genus of ancient crocodile has been discovered in Egypt, excavated from the same rocks used to build the Great Sphinx.
The find was revealed in a recent paper published in Royal Society Open Science, reinvestigating crocodile fossils first unearthed in the 1920s.
Ironically, the extinct crocodile fossil was missing the tip of its snout, just as the Great Sphinx is missing its nose. Researchers dubbed the crocodile Herugavialis cairensis, with the genus name denoting a connection to Egypt by incorporating the name of the sky god Horus, and the species name indicating it came from Cairo.
An Ancient Crocodile
The creature belonged to a group of freshwater crocodiles notable for their long, thin snouts, called gavials or gharials, which provide the “gavialis” portion of the new genus name. Only two gavial species remain, Gavialis gangeticus and Tomistoma schlegelii, residing in India and Southeast Asia. However, a 100-million-year fossil record indicates that this group once flourished globally.
A century ago, during the initial analysis of the fossils, researchers concluded they belonged to Tomistoma because of superficial skull features. Those investigators had only a mostly intact skull to work with in their classification, pulled from the Mokattam Formation. The site is a limestone quarry that supplied some of Egypt’s most important construction projects, including the Great Pyramid, Medieval Cairo, and the aforementioned Great Sphinx.
A Complicated History
The crocodile Tomistoma schlegelii has had a complicated taxonomic history. When scientists first cataloged it in the mid-nineteenth century, they noted its strange, hybrid-like appearance. Its jaw is narrow and filled with needle-like teeth, the hallmark of gavials. Yet the back of its skull and other skeletal features more closely matched the group Crocodylidae.
Because of this confusion, scientists created the genus Tomistoma to classify these strange crocodilians that exhibit features of both groups. This led to Tomistoma schlegelii being known as “the false gavial,” but the story didn’t end there.
Technology and methodology have made considerable strides in the almost two centuries since Tomistoma was first cataloged. Thanks to modern genetic testing, the controversy has been resolved: Tomistoma schlegelii isn’t false after all; it’s a member of the gavial group.
Reconsidering a Crocodile Fossil
Modern technology enabled much deeper analysis of the skull, including CT scanning and advanced paleontological techniques. Researchers from the UK, Sweden, Germany, and Egypt collaborated to identify enough differences from Tomistoma to declare a new Genus.
“We use phylogenetic analyses to quantify and corroborate our results. Herugavialis was never consistently recovered as closely related to any other species of gavial, so a new genus was warranted!,” lead author Dr. Paul Burke told The Debrief. “If, for example, Herugavialis was consistently recovered as closely related to species belonging to the genus Gavialis, it would give reason to refer the species to Gavialis, but this was not the case.”
Gavial crocodiles prefer shallow marine habitats, which covered the region when Herugalialis was alive, and also supported two other contemporary gavial species.
“It’s exciting, as for so many years, several fossils were assigned to the genus Tomistoma, due to their resemblance to the extant false gharial, Tomistoma schlegelii,” Dr. Burke said. “However, as our understanding of this group has improved through technological advancements within palaeontology, we can see just how different these species are.”
“Throughout much of the last 50 million years, the Mediterranean region hosted a high diversity of crocodiles, including gavials,” Dr. Burke concluded. “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 6 million years ago.”
The paper, “Cranial Anatomy of the Middle Eocene Egyptian Crocodylian Herugavialis Cairensis Provides New Insights into Gavialoid Diversity in the Mediterranean Region,” appeared in Royal Society Open Science on October 6, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.