A life reconstruction of Spicomellus afer, an ankylosaur fossil discovered in Morocco. Image courtesy of Matthew Dempsey
Joel Kontinen
A
165-million-year-old ankylosaur from the Atlas Mountains of Morocco was covered
in an array of extreme armour including body spikes fused to its skeleton, a
feature never seen in any dinosaur before
When Adam and Eve sinned, the world turned around. The animals that could protect themselves
at times grew plates and spines so they
would not be killed.
A dinosaur fossil found in Morocco may be the most bizarrely
and elaborately armoured vertebrate that has ever walked the planet.
The first fossil of Spicomellus afer was
discovered in Morocco and reported in 2021. It was only a rib fragment with
fused spikes, suggesting that it belonged to a group of dinosaurs known as
ankylosaurs. These short-limbed, wide-bodied herbivorous dinosaurs are
characterised by their covering of plates and spines.
Then, in
October 2022, a farmer in the badlands of Morocco’s Middle Atlas mountains
began to excavate a much more complete Spicomellus skeleton. That
fossil has now been dated to 165 million years ago, in the Jurassic Period. The
creature was probably about 4 metres long and weighed up to 2 tonnes.
Armoured dinosaurs such as stegosaurs and ankylosaurs, like
modern crocodiles, had bony plates that sat in the skin called osteoderms. But
in the Spicomellus fossil, there are two different types of bony
armour: osteoderms and spikes that are actually fused to the bone.
“It’s unheard of among armoured dinosaurs, and indeed
anything that has osteoderms, which is totally crazy,” says Susannah
Maidment at the Natural History Museum in London, a member of the team
that analysed the fossil.
In total, the Spicomellus specimen has dozens of
armoured spikes covering almost its entire body. Some spikes attached to a neck
collar are nearly a metre in length. There are also fused vertebrae in the
tail, indicating that it may have been a fierce weapon.
The creature was so bizarre, says Maidment, that she “ran
out of hyperboles to describe it”. “You can’t use words like ‘crazy’ in a
scientific paper, and I kept using words like extreme and elaborate,” she says.
“Then one of my colleagues suggested another way of trying to get across the
unusualness of this thing was to describe it in the study as ‘baroque’.”
Such
extreme armour would have severely limited the species’ capacity to navigate
its environment and would have made living anywhere with dense vegetation
almost impossible, says Maidment. “It would have just kept getting stuck
everywhere,” she says.
The armour is so complex that the researchers think it had
another function in addition to defence, such as to attract mates. “Things that
appear to be totally impractical in the fossil record almost invariably relates
to sex in some way or other. And so, you know, we think it is most
likely to be some sort of display.”
By James Woodford 2025
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