A crew of paleontologists introduced this week the invention of the oldest-known ankylosaur, a swaggering dinosaur well-known for its armor plating and clubbed tail. However in addition to 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 recall to mind a tank, and paleontologists not too long ago urged the animals might have even burrowed into the bottom to guard themselves. However 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, however in our specimen they’re fused to the ribs. This can be a morphology not seen in some other ankylosaur, and certainly in some other vertebrate, residing or extinct,” Susannah Maidment, a paleontologist on the Pure Historical past Museum in London, informed Gizmodo in an e mail. The analysis was co-authored by scientists on the College of Fez in Morocco and the College of Zürich in Switzerland.
“The armour of ankylosaurs was most likely a defensive mechanism,” stated Maidment, who’s lead creator of the current paper. “It could have definitely been off-putting for predators to chunk down on an animal lined in sharp spines like these!”
Your complete fossil consists of a sequence of spikes, acquired by the Nationwide Historical past Museum from a fossil supplier in 2018. The smallest spike is a little bit over 2 inches tall and the tallest is sort of 4 inches tall, although it’s lacking its tip. Should you had been a meat-eating theropod, it probably wouldn’t be your first alternative for a meal.
The analysis crew wasn’t positive at first what kind of dinosaur the fossil fragments belonged to. The fossil got here out of the Center Atlas mountain vary of Morocco, the place stegosauruses as soon as roamed, in order that was a risk. It wasn’t till the crew scrutinized the bone underneath 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 offers the species its identify: Spicomellus—“collar of spikes”—afer—“of Africa.”
“This can be a actually weird-looking specimen, however ankylosaur osteoderms are available some fairly shocking styles and sizes. A number of 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, informed Gizmodo in an e mail.
“It’s actually nice to have one other potential Center Jurassic ankylosaur, because the fossil file of ankylosaurs from this time interval is so scant, and I feel this provides some attention-grabbing new proof towards the concept stegosaurs had been outcompeted by ankylosaurs on the finish of the Jurassic,” added Arbour, who was not concerned within the current examine.
Proof of ankylosaurs is plentiful within the Cretaceous interval, however S. afer relationship from the Jurassic affords a tantalizing glimpse into the animals’ extra historical roots. Maidment stated that the analysis crew hopes to return to the identical rock that this fossil got here from to see if extra ankylosaurs from the time interval might be discovered.
In that case, it could assist paleontologists perceive if S. afer’s spike development was the rule or the exception—whether or not it was a mannequin for extra historical ankylosaurs or an aberrant member of the armor-plated dinosaur household tree.
Extra: Armored Dinos Might Have Dug Trenches to Defend Themselves, Research Suggests