This Incredible Dinosaur Sported The Spikiest Armor The World Has Ever Seen

The oldest ankylosaur known from the fossil record appears to have carried the most extreme body ornamentation ever documented in a vertebrate - even compared with other ankylosaurs.

Spicomellus afer - the earliest ankylosaur with extraordinary spikes

Spicomellus afer, which lived in the Middle Jurassic more than 165 million years ago, wasn’t merely studded with spikes along its body and on a club-like tail. It also bore elaborate rings of enormous spikes around its neck and hips.

"I've spent my career working on armoured dinosaurs but I'd never seen anything like this," palaeontologist Susannah Maidment of the London Natural History Museum told ScienceAlert.

"There were so many shapes and sizes of spikes: some joined together to make spikey compound structures; several ribs with spikes attached to their top surfaces; tear-drop shaped plates; and a whole bunch of things that I couldn't even identify. And then there was this collar-like bone with metre-long spikes sticking out from it. At that moment I realized we were looking at something unlike anything anyone had ever found before."

Ankylosaurs, armour, and a fossil discovery that went far beyond expectations

Ankylosaurs rank among the most compelling creatures to have walked the Earth. Their thick skins - reinforced with heavy, bony armoured plates, knobs, and spikes - readily conjure up visions of dramatic dinosaur clashes, with an ankylosaur holding its ground to avoid becoming another animal’s dinner. In fact, one of the most remarkable dinosaur fossils ever recovered is an ankylosaur preserved so perfectly that its armoured back remains intact.

Spicomellus is the earliest known member of the Ankylosaurus genus, a lineage that later reached its peak in the Cretaceous. Until recently, Spicomellus itself was represented only by a single partial rib bone discovered in Morocco, which scientists used to formally describe the species in 2021.

That specimen also marked the first ankylosaur found on the African continent. Then, in 2023, a local farmer in Morocco reported that he had recovered several unusual bones - ones he had managed to rescue from floodwaters. With the appropriate permit, researchers travelled to inspect the material and excavate the site where it was recovered, hoping more remains might still be there.

What they found exceeded anything they anticipated.

"It was immediately clear that it was jaw-droppingly weird – seeing those fossils for the time was genuinely spine-tingling," palaeontologist Richard Butler of the University of Birmingham in the UK told ScienceAlert.

"As we excavated more of the fossil ourselves and prepared the rock from around the fossils it became stranger and stranger."

A dinosaur bristling with spikes

In terms of spikiness, Spicomellus was in a league of its own - wildly more so than anyone would expect. Its skeleton was densely armed with bony projections, with the longest reaching up to 87 centimetres (about 0.87 metres) from the collar around its neck. While alive, those spikes were probably even longer.

Selection of Spicomellus afer bones. (Maidment et al., Nature, 2025)

"All of the ribs of Spicomellus that we have so far have three or four large spikes coming out of them. No other animal that we have ever found – alive or dead – has been discovered with spikes like these on its ribs," Butler elaborated.

"But not only this – Spicomellus also had an armor shield over its pelvis with large spikes coming out of it and a collar of armor around its neck with spines the length of golf clubs, a metre or more in length. This armor morphology is completely unlike that in any other known ankylosaur."

Defence, display, and why such armour may not have been practical

The prevailing view is that ankylosaur armour was mainly defensive. Yet the armour on Spicomellus appears so excessive and cumbersome that it may not have offered much practical benefit in day-to-day survival. That opens up the possibility that the spikes served a different purpose in the animals’ lives.

"Spicomellus had metre-long spikes extending from a bony collar around its neck. Presumably this would have been a bit annoying to carry around and is massive overkill to prevent something biting you, so we think that this armor was actually used for display rather than defence," Maidment explained.

"Today, animals that have structures with no obvious function tend to use them for display: for example, a deer's antlers or a peacock's tail. Perhaps Spicomellus used its armor in courtship displays, fighting, or to attract a mate."

So: the equivalent of punks at a rave - understood.

Why later ankylosaurs may have become less extreme

Butler pointed out that it’s striking to see such elaborate features in such an early representative of a broader group. The reduction or loss of such extravagant armour could reflect different environments, or ecological shifts between the Jurassic and the Cretaceous - a period that later included the rise of predators such as Tyrannosaurus rex. A large, ornate neck frill might have reduced an animal’s chances of survival, whereas more functional plates could improve it, leading to evolutionary pressure favouring plainer structures.

It’s also plausible that other extremely spiky ankylosaurs existed but have not yet been discovered. Finds like those could help bridge gaps between Spicomellus and later ankylosaurs.

Keeping the site secret while searching for more Spicomellus

For now, scientists can say with certainty that Spicomellus existed - and that it was exceptionally strange. The next move is to return to the area where it lived and attempt to locate additional specimens, though that effort is complicated by widespread fossil poaching in the region. The team noted that Spicomellus bones appeared to be for sale in Europe, potentially originating from the same individual described in their new paper.

As a result, the researchers are not disclosing the precise location, hoping this will give them a better chance to learn more about the unusual, spectacular animal.

"Our team will continue to explore the exciting and never-before-seen ecosystem in the Middle Atlas Mountains," Maidment said. "We hope to reveal many more weird dinosaurs, and perhaps another skeleton of Spicomellus. It would be great to find its skull!"

The research has been published in Nature.