These ankylosaur spikes grew directly on his ribs

A team of paleontologists this week announced the discovery of the oldest-known ankylosaur, a famous swagger dinosaur for its armor and clubbed tail. But in addition to its superlative age of over 160 million years, the ankylosaurus also had an odd morphology, as the spines protruding from the animal’s back were fused to its ribs.

Ankylosaurs were built to defend themselves. Their thick skulls and bulletproof vests are reminiscent of a chariot and paleontologists recently suggested animals may even have buried themselves in the ground for protection. But the newly named species, Spicomellus after, stands out among these hardy creatures, as described by researchers in their new paper, published yesterday in Nature Ecology & Evolution.

“All ankylosaurs had spikes on their backs, but in our specimen they are fused to the ribs. This is a morphology not found in any other ankylosaur, and even in any other vertebrate, living or extinct ”, Susannah Maidment, paleontologist at the Natural History Museum in London., Gizmodo said in an email. The research was co-authored by scientists from the University of Fez in Morocco and the University of Zurich in Switzerland.

“The ankylosaur armor was most likely a defensive mechanism,” said Maidment, who is main author of recent article. “It would certainly have been off-putting for predators to bite an animal covered with sharp thorns like these!”

The entire fossil consists of a series of points, acquired by the National History Museum from a fossil dealer in 2018. The smallest point is just over 2 inches tall and the tallest is almost 4 inches tall, although it lacks its tip. If you were a carnivorous theropod, this probably wouldn’t be your first choice for a meal.

The research team was not sure at first what kind of dinosaur the fragments of fossils belonged to. The fossil came from the Middle Atlas mountain range in Morocco, where Stegosaurs once roamed, so it was a possibility. It wasn’t until the team examined the bone under a microscope and saw the unique structure of osteoderms (the plate-like armor that protected animals) that they realized they were looking at an ankylosaur, the first ever found in Africa. . This also gives the species its name: Spicomella—“spike necklace” –close– ” of Africa “.

“It’s a really strange looking specimen, but ankylosaur osteoderms come in some pretty surprising shapes and sizes. Several species from Europe, like the Hungarosaurus, have cone-shaped tips like this one, ”Victoria Arbor, paleontologist at the Royal British Columbia Museum in Canada specializing in ankylosaurs., Gizmodo said in an email.

“It’s really great to have another potential Mid Jurassic ankylosaur, since the fossil record of ankylosaurs from this period is so scarce, and I think this adds some interesting new evidence against the idea that stegosaurs were supplanted by ankylosaurs in the late Jurassic, ”added Arbor, who didn’t was not involved in the recent study.

There is plenty of evidence for ankylosaurs in the Cretaceous, but S. afer dating from the Jurassic period offers a tantalizing glimpse into the oldest roots of animals. Maidment said the research team hopes to return to the same rock as this fossil has come to see if more ankylosaurs from the time period can be found.

If so, it would help paleontologists understand whether S. aferthe construction of ‘s points was the rule or the exception—whether it’s a model for older ankylosaurs or an aberrant member of the armored dinosaur family tree.

More: Armored dinosaurs may have trenches dug for protection, study finds