Femoral osteopathy in Gigantspinosaurus sichuanensis (Dinosauria: Stegosauria) from the Late Jurassic of Sichuan Basin, Southwestern China

ABSTRACT

We report a case of a specific osteopathy in the stegosaurian dinosaur Gigantspinosaurus sichuanensis from the Late Jurassic of Zigong City, China. The G. sichuanensis skeleton is very complete. The left femur has obvious pathological characteristics based on morphological observations. CT scans and energy spectrum data indicate the presence of multiple cystic-like low density areas internal to the pathological area, which are present in the form of multiple cystic low-density shadows in the CT data. This contrasts with the ‘normal’ area, which does not possess these characteristics. After comparing the specimen with the pathologic scapula of Yangchuanosaurus hepingensis (Dinosauria: Theropoda) also found in Zigong, we consider that the pathology in the left femur of G. sichuanensis was probably caused by a bone tumor. This is the first analysis with the aid of energy spectrum CT scanning of bone disease in fossils. This study increases the known information about paleopathology of stegosaurian dinosaurs and enriches the pathological knowledge of dinosaurs in general.

KEYWORDS:

• Stegosauria
• bone pathology
• Sichuan Basin
• energy spectrum CT

Acknowledgments

We would like to acknowledge the assistance and help of the following people in the production of this research: Mr FENG Hao and Mr ZHAO Zhi-Qiang from Zigong First People’s Hospital, GE CT training specialist Mr WAN Du-xing provided relevant images and data support. Mr HUANG Da-xi, Mr OUYANG Hui and Mr JIANG Shan provided valuable field geological materials. Ms LING Man, Ms LUO Shu drew the illustrations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences) (No. 183109), and Sichuan Province Land and Resources Department Project ‘Dinosaur fossil resources protection and development and utilization model in Sichuan Basin’ (No. KJ-2017-11).