Rare Spinosaurus Skull Fossils Found in the Sahara Desert

Scientists have found rare skull fossils belonging to Spinosaurus, an enormous carnivorous dinosaur, in the Sahara Desert for the first time in over a century.

The bones belong to a newly recognised type of Spinosaurus with a high bony crest on its head. They indicate that it caught fish in rivers, rather than swimming through deep open waters.

Skull fragments reassembled

Video from the desert dig shows a hand picking up skull splinters as thin as paper. Dr Paul Sereno of the University of Chicago began fitting those delicate pieces together to reconstruct a face.

“It's the most fragile and impossible thing to find,” said Dr Sereno.

Spinosaurus mirabilis has received a formal species name, while its skull provides evidence that earlier discoveries could not reveal.

Crest designed for display

A blade-like ridge rose above the snout, high enough to alter the dinosaur's silhouette against the clear sky.

Grooves in the bone indicate that keratin - the durable protein found in hair and nails - once covered and extended the crest.

Running along the centre of the skull, the crest resembled other decorative features that scientists associate with conspicuous display.

Its colour is still unknown, but a structure made to be seen suggests aspects of social behaviour that fossils seldom preserve.

Teeth adapted for fish

The interlocking teeth lining the long snout created a barrier that prevented slippery fish from escaping.

Measuring about 13 metres in length and weighing approximately 5,900 to 6,800 kilograms, the predator required a reliable and plentiful food source.

As the jaws shut, broader spaces near the hinge made room for prey and prevented the bite from becoming stuck.

Since its teeth locked together rather than cutting, fish and other river-dwelling animals probably appeared on its diet more frequently than terrestrial prey.

Debate over swimming

For years, debate has kept Spinosaurus in the headlines, as some specialists argued that it swam in deep water while others disagreed.

Studies of its tail bolstered the argument that the dinosaur could propel itself forcefully through water with side-to-side movements.

Subsequent research disputed that conclusion, saying the animal's body was too buoyant and unstable to operate as a genuine diving predator.

Discoveries in Niger, West Africa, provide further context, while a comparison of 43 predators supports the idea of an inland hunter that remained close to the surface.

Rivers far from the coast

Sand and mud deposited by rivers surrounded the bones, connecting the animal with a riverbank environment rather than a coastal shore.

Instead of evidence of tidal conditions, nearby fossils indicated freshwater fish and herbivores that sustained a rich landscape.

The distance from the sea matters, as waves can shift bones, whereas inland deposits retain a story that is more local to where it happened.

When viewed alongside long-necked dinosaurs, the predator appears to have been a regular inhabitant of rivers rather than a beach hunter.

Spinosaurids adapting to wetlands

Over tens of millions of years, spinosaurids - long-snouted meat-eaters with sails on their backs - moved ever closer to water.

Jaws suited to catching fish developed early, and later branches spread around the warm seas that once covered parts of Africa and Europe.

By roughly 95 million years ago, giants including Spinosaurus mirabilis ruled shallow channels and wetlands. Rising sea levels and climate change later reduced those habitats, and the group became extinct.

Desert fieldwork remains hazardous

After departing Agadez, a city in northern Niger, the convoy crossed around 300 kilometres of pathless sand to reach its camp.

At midday, temperatures approached 50°C, and one water lorry restricted the length of time the team could excavate before taking a break.

A force of 64 armed guards accompanied the group to discourage looters and safeguard the fossils in storage.

After three months of this routine, the team had recovered just a small number of fragile bones, illustrating why such work remains uncommon.

A name with a history

In 1915, fossils discovered in Egypt yielded the holotype of Spinosaurus aegyptiacus - the individual specimen used to name a species.

A study relied on photographs to recover information after the original bones were subsequently destroyed. Newly found skull fragments from Niger provide missing points of reference, meaning comparisons no longer depend solely on museum drawings.

With two species now recorded, researchers can investigate which characteristics remained consistent and which developed separately.

Fossils and local futures

Following work in UChicago laboratories, the team intended to send the fossils back to Niger and establish local museums.

Beyond museum displays, Sereno outlined training schemes in which UChicago specialists assist Niger in developing its own museum and fieldwork staff.

Local stewardship transforms education because pupils can encounter their country's history first-hand, rather than only reading about it overseas.

Common standards for loans and documentation remain important, as delicate bones can disappear through theft, damage or administrative failures.

What the bones reveal

Skull evidence, inland geology and years of debate now collectively support a Spinosaurus that caught fish in shallow water.

Further fossils from the same rock formations could reveal how the crest varied among individuals and how quickly rising seas brought the group to an end.