Paleontologists have discovered the remains of a deep-snouted tyrannosaurid dinosaur named Asiatyrannus xui in southeastern China.
The fossil remains of Asiatyrannus xui, the first deep-snouted tyrannosaur from Ganzhou City of southeastern China. Image credit: Zheng et al., doi: 10.1038/s41598-024-66278-5.
Asiatyrannus xui roamed our planet during the Late Cretaceous epoch, approximately 69 million years ago.
The new species was a member of Tyrannosaurinae, one of the two extinct subfamilies of Tyrannosauridae — the most derived group within the superfamily Tyrannosauroidea.
“Tyrannosauroids are the most distinctive, best known, and most intensively studied groups of dinosaurs, and are represented by almost 30 species,” said led author Dr. Wenjie Zheng and colleagues from the Zhejiang Museum of Natural History.
“The earliest tyrannosaurs appeared in the Middle Jurassic, around 165 million years ago.”
“They became the apex predators in their respective ecologies during the final 20 million years of the Cretaceous in Asia and western North America.”
“The colossal body size and deep snout are the characteristics of the ecologically dominant latest Cretaceous tyrannosaurid species.”
Asiatyrannus xui is a small to medium-sized tyrannosaurine dinosaur, with a skull length of 47.5 cm (18.7 inches) and an estimated total body length of 3.5-4 m (11.5-13.1 feet).
“The new species was around half the size of Qianzhousaurus and other large-bodied tyrannosaurines in similar growth stages,” the paleontologists noted.
A nearly complete skull and partial disarticulated postcranial skeleton of the new dinosaur was found at a construction site in the Nanxiong Formation of Shahe Town in Ganzhou City, the Chinese province of Jiangxi, in September 2017.
“Asiatyrannus and Qianzhousaurus have different skull proportions and body sizes, suggesting they may occupy different ecological niches,” the researchers said.
“In the Campano-Maastrichtian of eastern/central Asia and Laramidia, the large carnivore guilds are monopolized by tyrannosaurids, with adult medium-sized predators rare or absent.”
“Scientists interpreted the ‘missing middle-sized’ niches in the theropod guilds of Late Cretaceous Laramidia and Asia may have been assimilated by juvenile and subadults of tyrannosaurid species.”
“In southeastern China, Qianzhousaurus undoubtedly occupied the apex predator niche, but Asiatyrannus might represent the small to medium-sized theropod niche between the large-bodied Qianzhousaurus and the diversified small-bodied oviraptorosaurs.”
The findings appear this week in the journal Scientific Reports.
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W. Zheng et al. 2024. The first deep-snouted tyrannosaur from Upper Cretaceous Ganzhou City of southeastern China. Sci Rep 14, 16276; doi: 10.1038/s41598-024-66278-5
Source : Breaking Science News