The first occurrence of a probable pachycephalosaurian hyoid element
5 affiliations
- 1Phillip and Patricia Frost Museum of Science, Miami, FL, United States
- 2Museum of the Rockies, Bozeman, Montana, United States
- 3American Museum of Natural History, New York, New York, United States
- 4Department of Anatomy and Cell Biology, Oklahoma State University, Tulsa, OK, United States
- 5The Children’s Museum of Indianapolis, Indianapolis, IN, United States
Abstract
Derived from the second pharyngeal arch, the hyoid complex is a free-floating midline structure that is situated posteroventrally to the lower jaw. While there are many known free-floating osseous structures—such as dermal ossifications, dinosaurian ossified tendons/myosepta, and the mammalian baculum/baubellum—the hyoid complex is one of the few examples of these ‘floating’ bony elements that is found widely across the vertebrate bauplan. In terrestrial vertebrates, the hyoid complex is an important structure for vocalization, feeding, and respiration. A gracile, delicate, and multi-component structure in close proximity to heavily predated tissues, the hyoid complex is not a taphonomically favored structure; and yet, despite these taphonomic challenges, within Dinosauria, the primary osseous portion of the hyoid complex, the ceratobranchial, is sufficiently documented within many clades—save Pachycephalosauria. Previously, there were no known or suspected ceratobranchials reported from any pachycephalosaurian, making it one of the few osseous elements entirely unknown from this clade. Here, we report on a bony element which we hypothesize to be a right ceratobranchial from the holotype of the late Maastrichtian “ Dracorex hogwartsia .” This element was found associated with the holotypic material—though never reported—and its overall morphology, such as being anteroposteriorly elongate and transversely thin ( e.g ., ‘rod-like’), is congruent with ceratobranchial morphology from other dinosaurian taxa. If our identification is correct, this not only marks the first occurrence, and one of the remaining ‘blank spots’ of the pachycephalosaurian skeleton to be ‘filled in,’ but also has potential physiological and osteohistological implications for better understanding this enigmatic dinosaurian clade.
Related
- First urban occurrence of the Japanese grape leafhopper Arboridia kakogawana (Matsumura, 1932) (Hemiptera: Cicadellidae) in Italy
- Hyoid barbels as a key innovation triggering goatfish adaptive radiation
- Pyrophilic smoke flies (Diptera: Platypezidae: Microsaniinae) from prescribed burnings in boreal Finland: occurrence and behaviour of adult flies and first observations of immature stages
- First occurrence of a herrerasaurid dinosaur in a traversodontid cynodont-dominated Late Triassic fauna of southern Brazil.
- First Genetic Evidence Confirming the Occurrence of the Siberian Chiffchaff Phylloscopus collybita tristis Blyth, 1843, in Italy.
BibTeX
@article{woodruff2026first,
title = {{The first occurrence of a probable pachycephalosaurian hyoid element}},
author = {D. Cary Woodruff and Holly N. Woodward and Laura Rooney and Joseph Frederickson},
journal = {PeerJ},
year = {2026},
month = oct,
doi = {10.7717/peerj.21719},
url = {https://peerj.com/articles/21719},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The first occurrence of a probable pachycephalosaurian hyoid element
AU - D. Cary Woodruff
AU - Holly N. Woodward
AU - Laura Rooney
AU - Joseph Frederickson
PY - 2026
DA - 2026/10/21
JO - PeerJ
DO - 10.7717/peerj.21719
UR - https://peerj.com/articles/21719
AB - Derived from the second pharyngeal arch, the hyoid complex is a free-floating midline structure that is situated posteroventrally to the lower jaw. While there are many known free-floating osseous structures—such as dermal ossifications, dinosaurian ossified tendons/myosepta, and the mammalian baculum/baubellum—the hyoid complex is one of the few examples of these ‘floating’ bony elements that is found widely across the vertebrate bauplan. In terrestrial vertebrates, the hyoid complex is an important structure for vocalization, feeding, and respiration. A gracile, delicate, and multi-component structure in close proximity to heavily predated tissues, the hyoid complex is not a taphonomically favored structure; and yet, despite these taphonomic challenges, within Dinosauria, the primary osseous portion of the hyoid complex, the ceratobranchial, is sufficiently documented within many clades—save Pachycephalosauria. Previously, there were no known or suspected ceratobranchials reported from any pachycephalosaurian, making it one of the few osseous elements entirely unknown from this clade. Here, we report on a bony element which we hypothesize to be a right ceratobranchial from the holotype of the late Maastrichtian “ Dracorex hogwartsia .” This element was found associated with the holotypic material—though never reported—and its overall morphology, such as being anteroposteriorly elongate and transversely thin ( e.g ., ‘rod-like’), is congruent with ceratobranchial morphology from other dinosaurian taxa. If our identification is correct, this not only marks the first occurrence, and one of the remaining ‘blank spots’ of the pachycephalosaurian skeleton to be ‘filled in,’ but also has potential physiological and osteohistological implications for better understanding this enigmatic dinosaurian clade.
SN - 2167-8359
ER -