In a new paper published on January 31, 2024 in the journal Historical Biology, paleontologists announced the discovery of a previously undocumented species of dinosaur related to the famous Stegosaurus.
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Hypothetical reconstruction of Yanbeilong ultimus. Image credit: Ddinodan / Sci.News.
Stegosaurs were a group of plant-eating armored dinosaurs that lived during the Jurassic and Cretaceous periods.
These dinosaurs were four-legged and reached a maximum length of about 9 m (30 feet).
They had small heads, peg-like teeth, vertical bony plates and spines on their back and tail, and hoof-like toes on all four limbs.
“Stegosaurs are a minor but iconic clade of ornithischian dinosaurs,” said Dr. Lei Jia from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences and colleagues.
“They range from the Middle Jurassic to the Early Cretaceous, but are rare and poorly represented in the Cretaceous.”
“Before our study, there were only four valid taxa from the Cretaceous: Paranthodon, Wuerhosaurus homheni, Wuerhosaurus ordosensis and Mongolostegus exspectabilis.”
The fossilized bones of Yanbeilong ultimus. Image credit: Jia et al., doi: 10.1080/08912963.2024.2308214.
The new species from the Cretaceous, Yanbeilong ultimus, lived in what is now China between 113 and 100 million years ago.
The stegosaur’s fossilized remains were collected from the Zuoyun Formation of Zuoyun County, the Chinese province of Shanxi.
“Yanbeilong ultimus represents one of the latest records of a stegosaurian taxon in the world,” the paleontologists said.
“Compared to other stegosaurs, Yanbeilong ultimus has several unique characteristics in dorsal vertebrae and ilio-sacral block.”
“It has a higher neural arch and smaller neural canal of dorsal vertebrae, and it has fewer number of fused vertebrae/sacrals and fenestrae/sacral ribs in the ilio-sacral block.”
“The phylogenetic analysis shows that Yanbeilong ultimus is recovered as the sister taxon to a clade containing Stegosaurus stenops and Wuerhosaurus homheni,” they added.
“But it differs from these two taxa in several anatomical characters of dorsasacral vertebrae ribs, sacral ribs, caudal vertebrae and ilium.”
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Lei Jia et al. A new stegosaur from the late Early Cretaceous of Zuoyun, Shanxi Province, China. Historical Biology, published online January 31, 2024; doi: 10.1080/08912963.2024.2308214
