image: This paper elucidates the ecological context of two theropod dinosaurs of differing body sizes inhabiting the lakeshore region of Otog Banner, Inner Mongolia. The larger theropod exhibited a walking gait characterized by relatively short stride lengths, whereas the medium-sized theropod demonstrated a digitigrade posture indicative of rapid locomotion, achieving speeds up to 45 km/h. This represents the highest recorded speed among theropod dinosaur trackways from the Cretaceous period worldwide to date. Furthermore, these findings provide critical empirical evidence for advancing the understanding of the maximal locomotive capabilities of medium-sized theropods.The results were published as the cover paper in the 11th issue of Science China: Earth Sciences for 2025.
Credit: ©Science China Press
This study is led by Professor Wang Xiaolin and Associate Professor Jiang Shunxing from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; Dr. Li Yang from Shenyang Normal University; and Qi Muren, Zhang Lifu, and Wu Qi from the West Ordos National Nature Reserve Administration of Inner Mongolia. The research team performed a comprehensive analysis of recently uncovered dinosaur footprints from the Lower Cretaceous in Inner Mongolia. The sedimentary layer containing the footprints produced four distinct trackways alongside two isolated imprints, which have been attributed to large and medium-sized theropod dinosaurs, identified respectively as Chapus lockleyi and undetermined member of the Eubrontidae. Of particular significance, one trackway, recently revealed through cleaning efforts, extends up to 81 m, representing the longest known dinosaur trackway in China. Additionally, another trackway has been recognized as the fastest running theropod trackway documented from the Cretaceous period.
Based on the correlations among hip height, body length, and footprint length of the trackmakers, it is inferred that the medium-sized theropod dinosaur possessed a hip height of approximately 1.01 meters and a body length near 2.65 meters. In comparison, the average hip height and body length of the large-sized theropod trackmakers were estimated to be approximately 1.8 meters and 4.7 meters, respectively. Employing established methodological frameworks commonly utilized within the academic community for reconstructing rapid locomotion speeds and analyzing gait postures, the results suggest that the three large theropod dinosaur trackways correspond to slow walking behavior in a lacustrine environment. In contrast, the medium-sized theropod trackways are indicative of high-speed running, with estimated velocities reaching up to 45 or 41 ± 4.9 km/h. Through a systematic compilation and standardized analysis of globally published running track data, these findings demonstrate that the running trackway discovered in Inner Mongolia represent the fastest known theropod locomotion during the Cretaceous period.
This finding not only confirms the accuracy of biomechanical models used to estimate the maximum running speeds of medium-sized theropod dinosaurs but also provides significant fossil evidence supporting their highest locomotor capabilities.
See the article:
Li Y, Zhang L F, Jiang S X, Qi M R, Wu Q, Wang X L. 2025. The fastest-running theropod trackway in the Cretaceous from Ordos, Inner Mongolia, China. Science China Earth Sciences, 68 (11): 3495–3505. https://doi.org/10.1007/s11430-025-1657-7
Journal
Science China Earth Sciences