A 45-Million-Year-Old Fossil in Egypt Reveals a New Genus of Crocodiles.. What is its Connection to the Sphinx?

- A new genus may be added to the crocodile family tree. Through the analysis of fossil remains found in the same rock formation used to build the Sphinx, paleontologists have identified a new genus of crocodiles that roamed shallow marine environments in the area now known as Egypt, 45 million years ago. The Mokattam geological formation located in northern Egypt serves as a thick layer of limestone that preserved prehistoric marine fossils, including fish, sharks, and early whales.

This same limestone outcrop also provided a significant amount of raw materials that the ancient Egyptians used to build some of their most famous archaeological landmarks, including the Sphinx and the Pyramids of Giza. Now, scientists have managed to identify an extinct species of crocodile that lived millions of years before the Egyptians built those monuments.

The relationship between the crocodile samples and the famous landmarks is not limited to sharing the same geological source; one of the main fossils, a nearly complete skull, strikingly resembles the Sphinx, as the skull (first discovered in the 1920s) is missing the front part of its snout, in a notable similarity to the missing nose of the Sphinx. This feature inspired researchers to name the new genus "Herugavialis" in honor of "Hiro" or "Horus," the Egyptian god associated with the construction of the mythical creature.

The discovery of this species enhances scientists' understanding of the diversity and history of "Gharial crocodiles," a group of crocodiles with a complex evolutionary history, according to the authors of the study published Tuesday in the Royal Society Open Science journal. Paul Burke, the lead co-author of the study and a vertebrate paleontologist and postdoctoral researcher at the Swedish Museum of Natural History in Stockholm, stated: "Herugavialis kairinensis is one of six types of gharialids that we see in the Mediterranean region over a time span of 43 million years, specifically between 66 and 23 million years ago.

There may be other species that we have not discovered yet, of course." Burke explained in an email that today there are only two species of gharials found in the Indian subcontinent and Southeast Asia, but the fossil record of this lineage extends to all parts of the world, with samples found in various locations including the United Kingdom, Sweden, Italy, Egypt, and Japan.

In prehistoric Egypt, gharials are characterized by their long and slender snouts. The living species include the critically endangered Indian gharial (Gavialis gangeticus) and the false gharial (Tomistoma schlegelii), which is also threatened with extinction.

The false gharial acquired its name due to its resemblance to the Indian gharial, despite being a different species. In 1927, fossils that were analyzed in the new study (which included a skull and five other samples) were classified as belonging to an extinct species known as "Tomistoma cairense" based on their similarity to the living false gharial.

However, after conducting evolutionary analyses to assess the relationships between extinct and living crocodiles, and using computed tomography to examine the skull internally, the authors of the study found that the remains did not belong to the genus "Tomistoma." Philip Mannion, the co-lead author of the study and a professor of paleobiology at University College London, stated: "These samples were already known and classified as something distinct, but it required further meticulous work to determine what they specifically represented."

It became clear that the features of this crocodile indicate a new genus named "Hirogavialis." Burke, who was working on reconstructing the fossil structures of gharials as part of his PhD project, noticed subtle differences between this unknown species and the false gharial, prompting him to begin preparing a modern description of it in December 2023.

The paleontologist explained in an email that "Hirogavialis" possessed extremely pointed and sharp teeth, noting that "these teeth, along with the long and slender snout, were adapted for fish hunting." The skull of "Hirogavialis" was not discovered within the Sphinx itself, but it is known that the historical landmark, along with the pyramids, has discoveries dating back to ancient Egyptian and prehistoric times.

Scientists have previously discovered hundreds of thousands of small fossilized organisms buried within these massive structures. Alex Hastings, who holds the Fitzpatrick Chair of Paleontology at the Science Museum in Minnesota, USA, and did not participate in the study, noted that the reclassification of crocodile species "contributes to forming a clearer picture of the nature of the large predatory animals that lived in the region."

He also pointed out that the crocodile "Hirjafialis," like many other species, was initially classified within a genus that still exists today, despite the fact that this crocodile lived in a distant era. He added: "Studies like this provide important data that allow us to understand the true diversity and evolutionary background of these organisms, rather than merely classifying them within groups that are still alive."

It is worth mentioning that the study, which involved researchers from the Mansoura University Center for Vertebrate Paleontology in Egypt, was conducted on samples currently preserved at the State Museum of Natural History in Stuttgart, Germany, according to a statement published by the university's official page on Facebook on Tuesday.