Fossils unearthed in Morocco’s Atlas Mountains have revealed one of the most unusual dinosaurs ever discovered, a heavily armored plant-eater bristling with spikes that roamed the region around 165 million years ago.
The species, named Spicomellus afer, belonged to the ankylosaur family — squat, slow-moving herbivores protected by bony armor. At roughly 13 feet (four meters) long and weighing between one and two tons, it is now recognized as the oldest-known member of this dinosaur group.
Researchers say what sets Spicomellus apart is its extraordinary defensive and decorative features. Along its ribs ran sharp spikes, while a collar around its neck was ringed with long spines, some nearly three feet (one meter) in length. Its back, hips, and tail were also shielded with spikes and plates, and evidence suggests it may have wielded a tail weapon far earlier than previously thought for ankylosaurs.
“The armor of Spicomellus is jaw-droppingly weird, unlike that of any other dinosaur — or any other animal alive or dead — that we’ve ever discovered,” said Richard Butler, vertebrate paleontologist at the University of Birmingham and co-leader of the study published in Nature.
While some of the armor likely served to ward off predators, scientists believe the extravagant spikes may also have played a role in courtship or competition for mates, much like a peacock’s tail or a deer’s antlers.
An artistic reconstruction of the ankylosaur Spicomellus afer, based on fossils found in the Atlas Mountains of Morocco, shows the animal with the most extensive armor of any known dinosaur. Spicomellus lived about 165 million years ago during the Jurassic Period. The image was released on August 27, 2025. Matt Dempsey/Handout via REUTERS. NO RESALES. NO ARCHIVES. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY
“Spicomellus’ armor is totally impractical, and would have been a bit annoying in dense vegetation,” said Susannah Maidment of London’s Natural History Museum, who co-authored the study. “So we think it may have evolved as a display feature, perhaps to do with mating.”
The fossils, recovered in 2022 and 2023 near the town of Boulemane, include ribs, armor plates, hip spikes, and fused tail vertebrae — strongly suggesting a tail club or spiked weapon once tipped the dinosaur’s tail. Until now, such tail weapons were only known from ankylosaurs that lived much later.
The discovery challenges assumptions about dinosaur evolution. Early members of groups like ankylosaurs were thought to have relatively simple bodies compared to later species. Instead, Spicomellus shows that even the earliest ankylosaurs could be remarkably elaborate.
“The most elaborate ankylosaur armor of all time is present in the oldest member of the group,” Butler noted, suggesting later species evolved simpler defenses as predators like Tyrannosaurus became more formidable.
Though smaller than its famous relative Ankylosaurus, which lived 100 million years later in North America, Spicomellus afer stands out as one of the strangest armored dinosaurs ever found — a spiky survivor from the Jurassic whose discovery adds a new chapter to the story of dinosaur evolution.
