A Nearly Century-Old Fossil From the Sphinx's Limestone Just Turned Out to Be a New Crocodile Species
A century-old fossil from the same Egyptian limestone that built the Great Sphinx has been reclassified as a new crocodile species after micro-CT scanning revealed features the original classification missed.
A roughly 18-inch-long crocodilian skull discovered in Egypt nearly a century ago has just been corrected from a misclassification it’s carried since the 1920s. A team co-led by UCL researchers identified it as belonging to a new genus and species, Herugavialis cairensis, after micro-CT scanning revealed distinguishing features including a raised ridge around the eyes. The fossil had previously been assigned to the living Gharial-relative Tomistoma schlegelii — a misclassification that held for roughly a hundred years.
The rock the skull was found in is half the story. It comes from the Mokattam Formation, a 45-million-year-old limestone deposit — the same formation quarried to build the Great Sphinx. The creature that left this skull behind lived in the Eocene seas that later became the stone blocks that a civilization would carve into something else entirely, millions of years after the rock was laid down.
The species was named for Heru, the Egyptian god also known as Horus — a detail the Smithsonian Magazine noted in its coverage of the find. The study itself was published October 7, 2026 in Royal Society Open Science, with co-authors from UCL, the Swedish Museum of Natural History, Mansoura University in Egypt, and German institutions.
There’s a coincidence the researchers themselves noticed. The Sphinx is famously missing the tip of its nose. So is the crocodile skull. Two objects, carved and fossilized, separated by geological time — one worked by human hands millennia ago, the other shaped by whatever killed it in an Eocene sea — sharing an absence that makes both of them look like they lost a fight with the same rock.
What the CT scan actually turned up was anatomical specificity: the raised ridge around the eyes that distinguished Herugavialis cairensis from the species it had been lumped into. Details like that are exactly what micro-CT is for — non-destructive imaging that can resolve structures inside a fossil without damaging what’s been sitting in a museum case for decades. The skull had been telling the wrong story since the 1920s because the technology to read it properly didn’t exist yet.
The Mokattam Formation’s connection to the Sphinx means this particular limestone has been studied more than most, but that attention was geological and archaeological, not paleontological. A 45-million-year-old crocodilian sitting in the same rock that makes up one of the most examined monuments on Earth, misclassified for a hundred years — the find is less a case of new fossils turning up than of old ones finally being read correctly.