Novel Stegosaur Species Had Unprecedented Dermal Armor

A brand unique stegosaurian genus and species from the Heart Jurassic epoch has been identified from the postcranial stays learned in the Heart Atlas Mountains south of Fès, Morocco.

An AI’s influence of Thyreosaurus atlasicus. Image credit ranking: Sci.Data.

An AI’s influence of Thyreosaurus atlasicus. Image credit ranking: Sci.Data.

Thyreosaurus atlasicus lived in northern Africa at some level of the Heart Jurassic epoch, roughly 165 million years ago.

The species is intently connected to Dacentrurus, a member of the clade Dacentrurinae at some level of the thyreophoran dinosaur family Stegosauridae.

“Thyreophora is a various clade of herbivorous ornithischian dinosaurs composed of stegosaurs, ankylosaurs, and basal types,” acknowledged Dr. Mostafa Oukassou from the Hassan II University of Casablanca and colleagues.

“Thyreophorans ranking an intensive fossil file, spanning from the Lower Jurassic to the Upper Cretaceous, which is simplest known from smartly-preserved specimens in Laurasia.”

“In distinction, fossil stays are poorly known and largely partial in Gondwana,” they added.

“In Africa, thyreophorans would possibly per chance well ranking been unique for the rationale that Early-Heart Jurassic.”

“Stegosaurian physique fossils are documented in the Heart Jurassic of Morocco, the Upper Jurassic of Tanzania and the Lower Cretaceous of South Africa.”

“African ankylosaurs are represented handiest by Spicomellus afer from the Heart Jurassic of Morocco.”

The disarticulated partial skeleton of Thyreosaurus atlasicus was once learned in the gray marls of the El Mers III Formation in the northern Boulahfa locality, shut to Boulemane, Heart Atlas of Morocco.

“In 2021, at some level of a geological mapping mission south of Boulemane, we learned a singular scheme rich in dinosaur stays in the El Mers III Formation,” the paleontologists acknowledged.

“This scheme, named Boulahfa North, is positioned north of the Boulahfa quarry.”

“The fabric was once mute over several consecutive field journeys, and consists of a partial postcranial skeleton of a stegosaur that involves dorsal vertebrae and ribs, a limb bone and dermal armor.”

In step with the crew, Thyreosaurus atlasicus had an asymetric weird dermal armor, unfamiliar amongst stegosaurs.

“The dermal armor of Thyreosaurus atlasicus consists of thick — up to 4 cm (1.6 inches) — subovate to subrectangular-fashioned osteoderms,” the researchers acknowledged.

“The asymmetrical texture of their sides, one roughly ornamented with runt pits and fiber bundles, the assorted with a smartly-marked unpleasant-hatched pattern, is clearly assorted from that seen to this level in assorted stegosaurs, and ankylosaurs.”

“The bone histology of those osteoderms is paying homage to that of stegosaurian tail spines.”

“It’s interpreted that these osteoderms were organized in a recumbent express over the physique of the animal, as every other of an erect express.”

Thyreosaurus atlasicus had an estimated physique length of over 6 m (19.7 toes).

“Axial characters existing that the specimen belongs to a medium to mountainous-sized stegosaur,” the scientists acknowledged.

“The holotype corresponds to an grownup particular person that did now not attain its maximum physique size.”

The invention of Thyreosaurus atlasicus is serious in working out the evolutionary history of stegosaurs and assorted thyreophoran dinosaurs.

“The unique discoveries of Adratiklit and Thyreosaurus atlasicus present insight into the early evolution of stegosaurs in the Heart Jurassic of Africa,” the authors concluded.

The findings seem in the journal Gondwana Learn.


Omar Zafaty et al. 2024. A brand unique stegosaurian dinosaur (Ornithischia: Thyreophora) with a worthy dermal armour from the Heart Jurassic of North Africa. Gondwana Learn 131: 344-362; doi: 10.1016/