Footprint ecological restoration diagram. Drawing by Mauriio Oliveira, National Museum of Brazil
Recently, a team led by Wang Xiaolin, a researcher at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, in collaboration with Shenyang Normal University and the Administration of the West Ordos National Nature Reserve (Etuoke Dinosaur Relics and Fossils National Nature Reserve) in Inner Mongolia, discovered and studied the tracks of the fastest theropod dinosaur of the Cretaceous period, reaching speeds of up to 45 kilometers per hour. This new evidence provides new insights into the running abilities of medium-sized theropod dinosaurs. The research results were published in Science China: Earth Sciences.
Otog, Inner Mongolia, is the only national nature reserve in China dedicated to preserving dinosaur footprints. The team discovered a new footprint fossil site and identified two types of fossilized footprints, both large and medium, comprising four tracks and two isolated footprints.
One of the tracks, a medium-sized theropod dinosaur, consists of five continuous footprints, each measuring an average of 25.25 centimeters in length, with a combined stride length of 5.3 meters, indicating the maker was running at high speed. Using two commonly used methods, researchers calculated running speeds of up to 45 kilometers per hour and 41 ± 4.9 kilometers per hour, respectively. This represents a new global record for theropod dinosaurs of the Cretaceous period.
The remaining three tracks and two isolated footprints were left by large theropod dinosaurs. Each track averaged 44.92 centimeters in length, with a combined stride length of 2.5 meters. The track-makers were walking at a normal gait, corresponding to a speed of 6 to 8 kilometers per hour. Researchers recently cleared the soil covering the track's starting point, revealing 69 tracks, increasing the track's length to 81 meters, the longest theropod dinosaur track on record in China.
The newly discovered fast-running tracks coexist with those of large theropod dinosaurs. Researchers speculate that the reason why the dinosaurs that made the tracks ran so fast was, on the one hand, to hunt for food, and on the other hand, it is not ruled out that they were running to avoid being hunted by large theropod dinosaurs.
Related paper information: https://doi.org/10.1007/s11430-025-1657-7
(Original title: "How Fast Could Theropod Dinosaurs Run During the Cretaceous Period?")
