A nearly complete fossil skull dug up in Egypt in the 1920s — and misclassified for almost a century — has been identified as a genus and species science never knew: *Herugavialis cairensis*, a fish-eating croc that prowled the coasts of an ancient sea some 45 million years ago.
The skull comes from the Mokattam Formation limestone east of Cairo — the same rock unit quarried to build the Great Sphinx and the Giza pyramids. Nearly intact except for the tip of its snout, it mirrors the Sphinx's famously missing nose. In 1927 it was assigned to the known extinct species *Tomistoma cairense*, largely because of its resemblance to today's false gharial, *Tomistoma schlegelii*. An international team from Britain, Sweden, Germany and Egypt has now taken a second look: CT scans peering inside the skull, plus phylogenetic analysis, revealed enough morphological differences — eye sockets protruding like the rims of binoculars, a strip-shaped rather than wedge-shaped squamosal bone — to warrant a new genus. The study was co-led by Paul Burke of the Swedish Museum of Natural History and Philip Mannion, professor of palaeobiology at University College London.
The name *Herugavialis* combines Heru — the Egyptian god Horus, associated with the Sphinx's legend — with *gavialis*, the gharial group. "Given the coincidental resemblance to the Great Sphinx's famously missing nose, we decided to name the new crocodile after the Egyptian god Heru, who may have been the inspiration for the iconic monument," Mannion said.
The reclassification also rewrites its place on the crocodylian family tree: *Herugavialis* sits on a different branch from the modern gharials, a split that may date back to the Early Cretaceous — meaning the Mediterranean region's gharial diversity was far richer than previously thought.
With its long, slender snout and sharp teeth, *Herugavialis* was built for catching fish. The same strata preserve abundant bony and cartilaginous fish fossils — its likely prey. Around 45 million years ago this was a shallow coastline of the ancient Tethys Sea, and the new species shared it with at least two other fish-eating crocs. "For most of the past 50 million years, the Mediterranean region hosted a highly diverse assemblage of crocodylians, including gharials," Burke said.
Today, no wild crocodiles remain along the Mediterranean. The gharial lineage once ranged nearly worldwide across more than 100 million years of fossil record; just two species survive — the critically endangered Indian gharial (*Gavialis gangeticus*) and the endangered false gharial (*Tomistoma schlegelii*) of Southeast Asia. Burke's work suggests the region hosted at least six gharial species between 66 and 23 million years ago, waxing and waning with temperature and sea level, until the Mediterranean dried up around 6 million years ago and its crocodiles vanished.
The study, "Cranial anatomy of the Middle Eocene Egyptian crocodylian *Herugavialis cairensis* provides new insights into gavialoid diversity in the Mediterranean region" (DOI: 10.1098/rsos.261173), appears in *Royal Society Open Science*. Burke's redescription work began as a doctoral project in December 2023. The team expects more gharial fossils to surface in the region — the stone beneath the Sphinx, it seems, still has stories to tell.