Crocodile Fossil Is Missing Its Nose, Like the Great Sphinx

The Great Sphinx and a 45-million-year-old crocodile came out of the same rock, and both are missing their noses. The crocodile is Herugavialis cairensis. Its skull is nearly complete except for one detail: the tip of the snout is gone.

The shared rock is the Mokattam Formation, the layer the Sphinx was carved from. The skull was not prised out of the monument itself. It was collected east of Cairo in the 1920s and now sits in the Stuttgart State Museum of Natural History in Germany. Two icons of Giza came from the same rock, and neither of them kept its nose.

A new study in Royal Society Open Science, led by Paul Burke of the Swedish Museum of Natural History and Philip Mannion of UCL, found that this crocodile had been on the wrong branch of the family tree for nearly a century. Moving it is not just tidying up a label. Where a fossil sits on the tree decides which animals it gets compared with, and getting this one right changes the picture of which long-snouted crocodiles once lived around the Mediterranean.

That picture has a strange ending. Today the Mediterranean has no crocodiles at all, and the reason involves something far bigger than a missing nose: what happened to the sea itself.

Heru is the Egyptian god better known as Horus. He is often linked to the Sphinx, and Mannion describes him as possibly the monument's inspiration. That 'possibly' is doing honest work. When the team noticed their skull shared the monument's most famous flaw, the name more or less chose itself.

Mannion explained the choice directly: "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."

Every part of the name has a job. The ending, -gavialis, points to its relationship with the gharial, Gavialis gangeticus. The species name, cairensis, refers to Cairo.

Put together, the name reads roughly as "Heru's gharial from Cairo". That is a regal title for an animal that died about 45 million years before anyone carved a Sphinx.

• Heru

  The Egyptian god also called Horus, often linked to the Great Sphinx and possibly its inspiration.

• -gavialis

  Points to the animal's relationship with the gharial, Gavialis gangeticus.

• cairensis

  Refers to Cairo, east of which the skull was collected in the 1920s.

It earned a god's name by missing the same bit as the Sphinx.

No, although plenty of headlines said it was. The species was named in 1927 by Müller, who called it Tomistoma cairense and placed it with the living false gharial, Tomistoma schlegelii.

What is new is the genus. The paper creates Herugavialis, moves Müller's species into it, and changes the ending from cairense to cairensis to match. In the formal shorthand of taxonomy, that is Herugavialis gen. nov. and Herugavialis cairensis n. comb. (Müller, 1927).

According to Mannion, the fossil was already recognised as distinct but needed more detailed study to pin down what it actually was. That study combined CT scans of the skull's interior, bone-by-bone comparisons and a family-tree analysis based on a method called maximum parsimony.

The result was clear. Herugavialis does not group with the false gharial, and it does not group with the other Mediterranean species either. Its eye sockets are another giveaway. They are "telescoped", meaning raised and sticking out, one of the features that separates it from the false gharial.

So for nearly a century, a crocodile from the Sphinx's rock sat in a German museum filed under the wrong relative. Nobody had missed that it was unusual. What it was waiting for, as Mannion puts it, was a detailed modern restudy.

Picture a crocodile's head, then stretch the front until it looks like a pair of chopsticks. In Herugavialis, the snout makes up about 64% of the skull's length.

That long, thin profile is the signature of the gavials, a group of crocodiles that specialise in one item on the menu: fish. The study places Herugavialis as an early branch of the gavialoids, specialist fish-hunters that lived in warm, shallow seas over northern Egypt in the Middle Eocene.

It sits at the far end of the crocodile design range from a broad, heavy-headed species like the mugger crocodile. One head is a pair of tweezers. The other is closer to a club.

The teeth tell the same story. Burke says their shape suggests the animal ate mostly fish, and the Mokattam Formation preserves many kinds of bony and cartilaginous fish that it probably fed on. The rock that gave Egypt its most famous monument is also a fossilised seafood counter.

The rock that gave Egypt its most famous monument is also a fossilised seafood counter.

mugger crocodile

The gavial lineage goes back more than 100 million years. The fossil record holds more than 40 gavialoid species, spread across nearly the whole planet. Today, exactly two are left.

The gharial, Gavialis gangeticus, lives on the Indian subcontinent. The false gharial, Tomistoma schlegelii, lives in Southeast Asia and is endangered. Both carry the long, slender snout that defines the group.

Then there is the twist. Both survivors are freshwater animals, yet many of their extinct relatives lived in shallow seas. Herugavialis was one of them: a sea-going crocodile hunting fish where the Giza plateau now stands.

This is where the Egyptian skull's new address matters. For nearly a century it was treated as a cousin of the false gharial. Now its name nods to the gharial, and the study places it on an early branch of the whole group rather than beside either living species.

More than 40 species across 100 million years, and just two left, both in rivers.

About 45 million years ago, the ground under Giza was a warm, shallow sea, and at least three kinds of long-snouted, fish-hunting crocodile lived in it at the same time. Herugavialis was one of them.

Zoom out and the count grows. Burke says Herugavialis is one of six gavial species known from the Mediterranean region between 66 and 23 million years ago. Those six are spread across a 43-million-year span, not swimming side by side, so be wary of anyone who says the Eocene sea held six at once.

For tens of millions of years, then, the region was crocodile country. Today the Mediterranean has none.

According to Burke, crocodiles vanished from the Mediterranean about 6 million years ago, when the sea largely dried up. The fish-hunters had outlasted whole epochs. In the end, the water went out from under them.

The Mediterranean once had crocodiles. Then the sea itself nearly dried up.

You can't meet Herugavialis, but you can still meet its living relatives. The gharial lives in fresh water on the Indian subcontinent, and our guide to Animals in India is a good place to start if you want to see one.

Once you know the gavial silhouette, you will spot it instantly: a head that is mostly snout, lined with teeth built for fish. Put it next to a saltwater crocodile or a classic crocodile and the specialist design jumps out.

If you see a gharial, false gharial or mugger at a zoo or in the wild, AnimalDex lets you capture the real animal with your phone camera and add it to your collection. Keep your distance, let the animal be, and take a good look at that snout. It is the closest you will get to the crocodile that shares the Sphinx's rock.

Animals in Indiasaltwater crocodile