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| Qianjiangsaurus changshengi Dai, Ma, Xiong, Lin, Zeng, Tan, Wang, Zhang & Xing, 2025 in Q. Ma, Y. Ma, Tan, Chen, Lin, ... et Xing, 2026. |
Abstract
Cranial crests have evolved multiple times in the evolutionary history of vertebrates, serving primarily for visual display. In duck-billed lambeosaurines, one of the most successful dinosaur clades of the Late Cretaceous, the cranial crest became hollow along the paired premaxillae and nasals, and was secondarily selected as a resonating structure atop the skull roof, facilitating acoustic signaling. Here we report the first instance of a hollow supracranial crest in a non-lambeosaurine ornithopod dinosaur, the early-branching hadrosauroid Qianjiangsaurus changshengi, where the paired accessory endonasal cavities just above the nasal cavity proper occur following the dorsoventral thickening of the nasals. This novel nasal cavity configuration is associated with the helmet-like hollow supracranial crest solely formed by the nasals. Comparative resonance modeling suggests that the nasal cavity of Q. changshengi could amplify low-frequency vocalizations similar to those of late-branching lambeosaurines. Seven analogous skull features (including the hollow supracranial crest) and similar low-frequency acoustic capabilities of nasal cavities between Q. changshengi and late-branching lambeosaurines reveal a striking morphological and functional convergence that would likely facilitate safer, more efficient social communication among hadrosauroids. This convergence can be explained by adaptive evolution under similar selection pressures, combined with developmental constraints due to gene pleiotropy.
Keywords: Qianjiangsaurus changshengi; accessory endonasal cavities; hollow supracranial crest; low-frequency vocalizations; convergent evolution
Qianjiangsaurus changshengi
Qingyu Ma, Yubo Ma, Chao Tan, Jian Chen, Yu Lin, Ming Xiao, Hui Dai, Guangbiao Wei, Jordan C. Mallon, Jun Wang, Han Yao, Zhengting Zou and Hai Xing. 2026. First Report of a Hollow Cranial Crest in an Early-Diverging Duck-Billed Dinosaur, with Implications for Convergent Evolution of Acoustic Signaling. Biology. 15(8), 615. DOI: doi.org/10.3390/biology15080615 [13 April 2026]
Simple Summary: Convergent evolution is a peculiar biological process in which distinct taxa or lineages independently evolve analogous features, structures and functions, to adapt to similar necessities. Here we present a classic instance of morphological and functional convergence of the hollow cranial crest among hadrosauroid dinosaurs, based on an excellently preserved skull of the early-branching hadrosauroid Qianjiangsaurus changshengi newly recovered from southwest China, as well as comparative resonant frequency evaluations of its unique endonasal (‘within the nasal bone’) cavities using CT scans and mathematic calculations. The overgrown nasal crest with a novel internal structure in Q. changshengi is morphologically comparable to but structurally non-homologous with the greatly developed hollow supracranial ornamentation and elongate nasal passages seen in lambeosaurines, and thus hugely changes our notions on the cranial evolution of late-branching ornithopod dinosaurs.
