A life reconstruction of Spicomellus by Matthew Dempsey. Journal Nature

A dinosaur dubbed one of the "strangest" ever found boasted an elaborate armory of long bony spikes and a tail weapon, according to findings published in the science journal Nature.

Spicomellus, which roamed the Earth 165 million years ago, is the world's oldest ankylosaur, a herbivorous group of dinosaurs known for their tank-like bodies.

Palaeontologists' image of Spicomellus was based on a single rib bone found in Morocco in 2019.

But newly discovered remains have helped scientists form a clearer picture of the unusual dinosaur.

The fossils showed it had bony spikes fused onto all of its ribs — something never seen before in any other vertebrate species living or extinct, according to the research published Wednesday.

Richard Butler, a professor at the University of Birmingham and the project co-lead, told CBS News partner BBC News that it was the "punk rocker" of its time.

Butler called the fossils an "incredibly significant discovery," adding that "Spicomellus is one of the strangest dinosaurs that we've ever discovered."

Butler's project co-leader, Susannah Maidment of the Natural History Museum in London, added that it was surprising that the spikes were fused directly onto the bone, the BBC reported.

"We don't see that in any other animal, living or extinct," she said. "It's absolutely covered in really weird spikes and protrusions all over the back of the animal, including a bony collar that wraps around its neck and some sort of weapon on the end of its tail, so a most unusual dinosaur."

The discovery is so unusual that Butler and Maidment are considering whether the theories on how ankylosaurs evolved should be re-assessed.

These dinosaurs survived late into the time dinosaurs were on Earth, in a period known as the Cretaceous, the BBC reported. The end of this period saw the emergence of large carnivorous predators, such as T. Rex, so it had been thought that ankylosaurs started off with simple, small armored plates on their back, which then became larger and more extensive to protect themselves from these big beasts, according to Butler.

"If you had asked me what I would have expected the oldest known ankylosaur to look like I would have said something with quite simple armor," Butler told BBC News. "Instead, we have an animal bristling with spikes like a hedgehog, the most bizarre armor that we've ever found in any animal, far outside the range of armor seen in later ankylosaurs."

Source