The Liaoning Province in northeastern China is home to some of the most impressive fossil beds in the world. Farmers in the region recently uncovered the near-complete remains of a never-before-seen species of armored dinosaur. Examination of the fossils was led by Fenglu Han of the Chinese Academy of Sciences, who also serves as lead author of the paper published in PLOS ONE.
The new species, Chuanqilong chaoyangensis, lived about 110 million years ago in the Early Cretaceous period. It belongs to family Ankylosauridae, which are herbivorous, quadrupedal dinosaurs with heavy armored bodies.
This particular specimen was about 4.5 meters (14.7 feet) long, which is about as long as a mid-sized car. While that’s a pretty big beast, researchers suspect that the animal was a juvenile and could have reached lengths of 8 m (26 ft) as an adult. This species may have been among the largest of the ankylosaurs. Likely due to changes in the environment and availability of nutrients during the Cretaceous, many dinosaurs reached incredible heights.
This is the fourth known species of ankylosaur to be discovered in the region from the Cretaceous, which indicates there was a fair amount of diversity in the area. However, while many later members of the family Ankylosauridae had clumps of bone at the end of a tail that could be used as a club, C. chaoyangensis did not have that feature. The specimen was also lacking cranial armor. The researchers state that this would likely put the new species toward the base of the clade, before that trait evolved.
In order to declare the fossils as a new species, the researchers examined the dinosaur’s cheek teeth, humerus, pelvic bones, distance ratio from hind limbs to forelimbs, and unguals, which are claw-shaped bone digits. The features appeared novel, even when compared to other juveniles from different species.
However, the researchers hope to someday study an adult C. chaoyangensis, in order to get a better understanding of the species. Juvenile features are often underdeveloped, and gaps in the fossil record for other ankylosaurs make it unclear which traits change at certain points in development.
“Postcranial materials of Chuanqilong chaoyangensis. A, right scapula in lateral view; B, left humerus in cranial view; C, right humerus in lateral view; D, left ulna in medial view; E, left radius in medial view; F, disarticulated left metacarpals and phalanges; G, right femur in caudal view; H, left femur in cranial view; I, articulated left tibia and fibula in cranial view; J, right metatarsals in cranial view; unguals in both cranial and caudal view. Note that due to compression of the right femur, the cranial trochanter is visible in posterior view whereas it would normally be obscured. Abbreviations: dc, deltopectoral crest; fh, femoral head; fi, fibula; fth, fourth trochanter; gt, greater trochanter; lc, lateral condyle; ct, cranial trochanter; mc, medial condyle; ti, tibia.” Image credit: Han et al., 2014
[Hat tip: LiveScience]