Analysis of an unusual fossil showing a series of spines fused into a rib reveals that they are the remains of the oldest ankylosaurus ever found and the first on the African continent.
The discovery was made in the Middle Atlas Mountains of Morocco at the same site where researchers from the UK’s NHM (National History Museum) unearthed the oldest stegosaurus ever found.
The new species was described by Dr Susanna Maidment, NHM researcher and first honorary lecturer at the University of Birmingham, and named Spicomellus afer: Spicomellus meaning ‘spike collar’ and the other meaning ‘from Africa’.
“At first we thought the specimen could be part of a stegosaurus, as we had previously found it at the same site. But upon closer examination, we realized that the fossil was different from anything we had seen,” he said. statment.
The sample is so unusual that researchers initially wondered if it was a fake. A CT scan showed it was a real deal, and a cross-section of the specimen’s base showed a criss-cross pattern in the bone unique to ankylosaurs, revealing its identity.
“Ankylosaurs have armored spines that are generally embedded in their skin and do not fuse with bone. In this specimen we see a series of spines attached to a rib, which should be protruding above the skin covered with a layer of something similar to keratin,” Maidment explained. “It is unprecedented and unlike anything in the animal kingdom.”
Ankylosaurs were a diverse group of armored dinosaurs related to the more famous stegosaurus. They’ve been around throughout the Cretaceous period, but there is little evidence of them before then, making this new fossil not only the first to be found in Africa, but also the first example of the group ever discovered.
The new discovery dates back to the Middle Jurassic period about 168 million years ago. It helped fill an important gap in our understanding of dinosaur evolution and suggests that ankylosaurs may have had a global distribution.
This discovery also challenges an earlier theory that ankylosaurs outnumbered stegosaurs and led to their extinction. However, this new discovery means that the two groups coexisted for more than 20 million years, which means that the extinction of Stegosaurus may have occurred for other reasons.
The fossil that led to the description of this new species is now part of the NHM collections and will be the subject of ongoing study. The research was published in the journal Nature Ecology & Evolution.