A new species of extinct crocodile from Egypt has been discovered, sharing more than just its home with the Great Sphinx. Herugavialis cairensis was found in the very same rocks used to build the iconic monument. And, just as the Sphinx is famously missing the tip of its nose, the fossil crocodile is also missing the tip of its snout.
Gavials are a group of crocodiles that are characterized by their long, thin snouts. Today, they are found only in freshwater environments on the Indian subcontinent and Southeast Asia, with just two living species: Gavialis gangeticus and Tomistoma schlegelii, the 'false gharial'. However, the fossil record of gavials documents a near-global distribution, spanning more than 100 million years, with many species living in shallow marine environments.
New analysis reveals a new crocodile species
In the 1920s, several fossils were recovered from the 45-million-year-old Mokattam Formation in Egypt. These fossils, including a nearly complete skull, were described as belonging to Tomistoma, because of their superficial resemblance to the false gharial.
However, recent analytical advances in palaeontology, including the use of CT scanning to look inside the skull, allowed an international team of researchers to identify several differences between the false gharial and the fossils from the Mokattam Formation. The team, from the UK, Sweden, Germany and Egypt, was led by Dr Paul Burke, a researcher at the Swedish Museum of Natural History in Stockholm.
The skull of Herugavialis is relatively well preserved, but one feature in particular caught the researchers' attention: the tip of its snout is missing.
"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," says Professor Philip Mannion of University College London, who co-led the study.
Crocodile diversity in the ancient Mediterranean
Herugavialis was not the only crocodile in Egypt at the time. The shallow marine environments that 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," says lead author Dr Paul Burke.
"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."
