 |
| Pulaosaurus qinglong |
Abstract
The Middle and Late Jurassic Yanliao Biota is different from other contemporaneous fossil assemblages in that it lacks neornithischian dinosaurs. Here, we report a new, early-diverging neornithischian, Pulaosaurus qinglong gen. et sp. nov., from the Upper Jurassic Tiaojishan Formation of Qinglong, Hebei Province, of northern China. Diagnostic or noteworthy morphological characteristics of P. qinglong include: five premaxillary teeth; a small boss is present on the caudoventral corner of the dorsal ramus of the jugal; a nuchal crest is located along the parietal; the manus has five digits; a supra-acetabular crest is present on the ilium; the paired arytenoids are gracile and leaf-like in form; the obturator process along the ischium is located near the pubic peduncle; a notch-like shaped obturator opening is present within the pubis; a robust fibular condyle forms a dorsoventrally extending crest on the tibia; a subtriangular flange on the anterior surface of the astragalus extends dorsolaterally along three distal tarsals; three of the distal tarsals are unfused, including a small drop-shaped distal tarsal 3; distal tarsal 3 is pierced by a foramen. A phylogenetic analysis places P. qinglong as one of the earliest-diverging neornithischians yet described. Moreover, P. qinglong represents the second known dinosaur to preserve ossified laryngeal elements, thus suggesting that a bird-like vocalization evolved early in non-avian dinosaur evolution.
 |
| The photograph of the whole skeleton of Pulaosaurus qinglong in left lateral view (IVPP V30936). |
Dinosauria Owen, 1842
Ornithischia Seeley, 1887
Neornithischia Cooper, 1985
Pulaosaurus qinglong gen. et sp. nov.
Etymology: The generic name is derived from Chinese Pinyin for “Pulao”, a mythical creature resembling the Chinese dragon. According to Chinese legends, the “Pulao” engages in loud shouting, thus referencing the possible bird-like vocalizations of this species. The specific name is derived from the Chinese Pinyin for “Qinglong”, which is the name of the county in Province Hebei, China, where the specimen was found.
Locality and horizon: Southern Shimen Gou, County Qinglong, Province Hebei, People’s Republic of China. Tiaojishan Formation, Callovian-Oxfordian (Middle-Upper Jurassic).
Diagnosis: A small-bodied neornthischian dinosaur characterized by the combination of the following characteristics (autapomorphies preceded by an asterisk): five premaxillary teeth; a small boss is located on the caudoventral corner of the dorsal ramus of the jugal; a nuchal crest that is located on the parietal the mani have five digits; a supra-acetabular crest is located on the ilium; a pair of gracile, leaf-like arytenoids are present; the obturator process is near the pubic peduncle; the opening of the obturator on the pubis is notch-shaped; *a robust fibular condyle forms a dorsoventrally extending crest on the tibia; a subtriangular flange extends dorsolaterally on four distal tarsals; *three distal tarsals are unfused with distal tarsal three that is drop-shaped; distal tarsal three is pierced by a foramen.
...
Conclusions:
Pulaosaurus qinglong gen. et sp. nov. is an early-diverging neornithischian species found in the Upper Jurassic Tiaojishan Formation of Province Hebei, China. A phylogenetic analysis places Pulaosaurus at the base of Neornithischia close to Agilisaurus, which is the earliest-diverging neornithischian. Pulaosaurus represents the first neornithischian found in the Yanliao Biota, and helps to fill the temporal and geographical gap in the distribution of Neornithischia within China. A pair of arytenoids are preserved in the Pulaosaurus holotype and represents the second case of an ossified laryngeal apparatus among non-avian dinosaurs. The arytenoids of Pulaosaurus indicates that ossified laryngeal apparatuses were present in Neornithischia, thus suggesting that the ossified laryngeal apparatus could be widespread across Dinosauria. As the morphology of Pulaosaurus arytenoids resembles the arytenoids of extant birds, it is possible for Pulaosaurus to have an avian-like vocalization.
Yunfeng Yang, James L. King and Xing Xu. 2025. A New neornithischian Dinosaur from the Upper Jurassic Tiaojishan Formation of northern China. PeerJ. 13:e19664 DOI: doi.org/10.7717/peerj.19664 [July 11, 2025]
