CT scans reassign a crocodile skull recovered in Egypt in the 1920s to a new gavial species
Paul Burke's team used CT scans to name Herugavialis cairensis, a new gavial, from Egyptian fossils filed as Tomistoma since the 1920s. The reread adds a species to the Mediterranean's fossil crocodile record, which the authors tie to past changes in climate and sea level.
The Scientist · Science desk
What happened
- The fossils, a nearly complete skull among them, come from Egypt's Mokattam Formation, which phys.org describes as the same rock used to build the Great Sphinx.
- At least two other gavial species lived alongside Herugavialis in the shallow seas that covered much of the region.
- Only two gavials survive, Gavialis gangeticus and Tomistoma schlegelii, both in fresh water on the Indian subcontinent and in Southeast Asia.
- Gavial fossils span more than 100 million years and a near-global range, and many of those species lived in shallow marine settings.
Why it matters
- What doesn't add up contradiction PopSci puts Herugavialis in Egypt "when the Great Sphinx was built 4,500 years ago," yet its rock is about 10,000 times older than the monument, so the Sphinx link is the stone and the name.
- What it limits constraint The group's ancient range stays where the fossil record already had it; what Herugavialis adds is one more species in the Mediterranean diversity series the authors set against climate.
- What it sets up precedent A skull sat in the wrong genus for a century on outward resemblance, so other early Egyptian crocodile identifications made by eye are candidates for the same CT re-examination.
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The new name comes from old material [3]. According to phys.org's account, the fossils were assigned to Tomistoma in the 1920s "because of their superficial resemblance to the false gharial" [4]. PopSci's story opens on discoveries that "await deep inside the bedrock" of the Sphinx [12]. This one was made inside a skull [5]. CT scanning and other recent analytical methods let the team, drawn from the UK, Sweden, Germany and Egypt, identify several differences between the fossils and the living false gharial [5][2].
The skull is relatively well preserved, apart from the missing tip of its snout [7]. "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," said Philip Mannion of University College London, who co-led the study [8][2].
The paper's title presents the result as new insight into gavialoid diversity in the Mediterranean region during the Middle Eocene [11]. "Throughout much of the last 50 million years, the Mediterranean region hosted a high diversity of crocodiles, including gavials," said Paul Burke of the Swedish Museum of Natural History, the lead author [14][2]. "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." [14]
Burke's own word is "seemingly" [14]. He presents the final loss as a direct result of the sea drying out. The earlier swings in diversity he links to temperature and sea level only as a correspondence [14]. A species count that rises and falls with the climate fits a climate explanation without proving it. Testing it would mean knowing how many species were counted in each interval and how the two series were compared. The press accounts do not list the anatomical differences that separate Herugavialis from Tomistoma, and they do not say how that comparison was made [5].
What to watch
- Whether the full paper's list of cranial differences places Herugavialis nearer to Gavialis or to Tomistoma among living gavials.
- Whether other crocodile specimens taken from the Mokattam Formation in the 1920s are scanned and reassigned.
- Whether the authors test their Mediterranean diversity counts formally against temperature and sea-level records, beyond Burke's 'seemingly corresponding'.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence72
- Adoption
- Not scored
- Hype gap+15
- Incentives
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- Confidence70
Perspective Coverage
4 publishers- Builder
- Builder 40%
- Operator
- Operator 36%
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Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Herugavialis cairensis is a new species of extinct crocodile from Egypt, described in the journal Royal Society Open Science.
- [2]
The international team, from the U.K., Sweden, Germany and Egypt, was led by Dr. Paul Burke of the Swedish Museum of Natural History in Stockholm; Professor Philip Mannion of University College London co-led the study.
- [3]
In the 1920s, several fossils, including a nearly complete skull, were recovered from the 45-million-year-old Mokattam Formation in Egypt.
- [4]
The 1920s fossils were described as belonging to Tomistoma because of their superficial resemblance to the false gharial.
- [5]
Recent analytical advances in paleontology, including the use of CT scanning to look inside the skull, allowed the team to identify several differences between the false gharial and the fossils from the Mokattam Formation.
- [6]
Herugavialis cairensis was found in the very same rocks used to build the Great Sphinx.
- [7]
The skull of Herugavialis is relatively well preserved, but the tip of its snout is missing.
- [8]
"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,"
- [9]
Gavials today are found only in freshwater environments on the Indian subcontinent and in Southeast Asia, with two living species: Gavialis gangeticus and Tomistoma schlegelii, the false gharial.
- [10]
The fossil record of gavials documents a near-global distribution spanning more than 100 million years, with many species living in shallow marine environments.
- [11]
The paper is titled "Cranial anatomy of the Middle Eocene Egyptian crocodylian Herugavialis cairensis provides new insights into gavialoid diversity in the Mediterranean region," Royal Society Open Science (2026).
- [12]
PopSci wrote that mysteries linger and "discoveries await deep inside the bedrock" of the Great Sphinx, and that these discoveries now include a new species of extinct crocodile.
- [13]
Herugavialis was not the only crocodile in Egypt at the time; the shallow marine environments that covered much of the region were home to at least two other species of gavials.
- [14]
"Throughout much of the last 50 million years, the Mediterranean region hosted a high diversity of crocodiles, including gavials. 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."
- [15]
PopSci wrote: "When the Great Sphinx was built 4,500 years ago, Herugavialis was not the only crocodile in Egypt."
- [16]
The 45-million-year-old Mokattam rock is about 10,000 times older than the 4,500-year-old Great Sphinx, so Herugavialis could not have lived in Egypt when the Sphinx was built.
Sources
4 independent publishers whose own reporting we read for this story.
- discovermagazine.comThis Newly Identified Species of Extinct Crocodile is Missing the Tip of Its Nose, Just Like the Great Sphinx
1 article · October 6, 2026
- phys.orgNew crocodile species discovered in rocks used to build the Great Sphinx
1 article · October 6, 2026
- popsci.comNew crocodile species found in rocks of Egypt’s Great Sphinx
1 article · October 6, 2026
- sciencenews.orgAn extinct crocodilian was found among rocks that built the Great Sphinx
1 article · October 6, 2026
Topics and entities
Topics
- Crocodylian evolution
- Paleontology
Entities
- Swedish Museum of Natural History
- Mokattam Formation
- Royal Society Open Science
- Herugavialis cairensis
- Great Sphinx of Giza
- University College London
- Khalafallah Salih