These Spikes Grew Right Out of a Dinosaur’s Ribs

A staff of paleontologists introduced this week the invention of the oldest-known ankylosaur, a swaggering dinosaur well-known for its armor plating and clubbed tail. But moreover its superlative age of over 160 million years, the ankylosaur additionally had a weird morphology, as spines protruding from the animal’s again had been fused to its ribs.

Ankylosaurs had been constructed for protection. Their thick skulls and physique armor call to mind a tank, and paleontologists lately prompt the animals could have even burrowed into the bottom to guard themselves. But the newly named species, Spicomellus afer, stands out amongst these sturdy creatures, because the researchers describe of their new paper, revealed 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 seen in any other ankylosaur, and indeed in any other vertebrate, living or extinct,” Susannah Maidment, a paleontologist on the Natural History Museum in London, instructed Gizmodo in an electronic mail. The analysis was co-authored by scientists on the University of Fez in Morocco and the University of Zürich in Switzerland.

“The armour of ankylosaurs was most probably a defensive mechanism,” mentioned Maidment, who’s lead writer of the latest paper. “It would have certainly been off-putting for predators to bite down on an animal covered in sharp spines like these!”

The total fossil consists of a collection of spikes, acquired by the National History Museum from a fossil vendor in 2018. The smallest spike is just a little over 2 inches tall and the tallest is almost 4 inches tall, although it’s lacking its tip. If you had been a meat-eating theropod, it seemingly wouldn’t be your first alternative for a meal.

The analysis staff wasn’t certain at first what kind of dinosaur the fossil fragments belonged to. The fossil got here out of the Middle Atlas mountain vary of Morocco, the place stegosauruses as soon as roamed, in order that was a risk. It wasn’t till the staff scrutinized the bone below a microscope and noticed the distinctive construction of the osteoderms (the plate-like armor that protected the animals) that they realized they had been taking a look at an ankylosaur, the primary to ever be present in Africa. That additionally provides the species its title: Spicomellus—“collar of spikes”—afer—“of Africa.”

“This is a really weird-looking specimen, but ankylosaur osteoderms come in some pretty surprising shapes and sizes. Several species from Europe, like Hungarosaurus, have cone-shaped spikes like this,” Victoria Arbour, a paleontologist on the Royal British Columbia Museum in Canada who makes a speciality of ankylosaurs, instructed Gizmodo in an electronic mail.

“It’s really great to have another potential Middle Jurassic ankylosaur, since the fossil record of ankylosaurs from this time period is so scant, and I think this adds some interesting new evidence against the idea that stegosaurs were outcompeted by ankylosaurs at the end of the Jurassic,” added Arbour, who was not concerned within the latest examine.

Evidence of ankylosaurs is plentiful within the Cretaceous interval, however S. afer relationship from the Jurassic presents a tantalizing glimpse into the animals’ extra historic roots. Maidment mentioned that the analysis staff hopes to return to the identical rock that this fossil got here from to see if extra ankylosaurs from the time interval could be discovered.

If so, it might assist paleontologists perceive if S. afer’s spike development was the rule or the exception—whether or not it was a mannequin for extra historic ankylosaurs or an aberrant member of the armor-plated dinosaur household tree.

More: Armored Dinos May Have Dug Trenches to Protect Themselves, Study Suggests