Researchers in northern China have confirmed one of the country’s largest dinosaur footprint fields and identified evidence of what may be one of the slowest-moving carnivorous dinosaurs ever recorded.

The discovery comes from Xuanhua in Zhangjiakou, Hebei Province, where scientists documented a footprint field spanning roughly 30,000 square meters and preserving more than 5,000 tracks. Among them were trackways left by a small theropod dinosaur moving at only about 0.6 mph (one kilometer) per hour, which is roughly the pace of a walking tortoise.

The finding challenges the usual image of carnivorous dinosaurs as constantly fast-moving predators and instead offers a glance at their slower day-to-day behavior. Researchers say the tracks help reconstruct the ecosystem that existed in the region more than 100 million years ago and expand China’s already extensive record of dinosaur footprints.

One of China’s largest dinosaur track sites

According to Global Times reporting citing local geological surveys, the Xuanhua site preserves over 5,000 footprints across an exposed area of about 30,000 square meters, placing it among China’s largest dinosaur track discoveries.

Site I had already been known for preserving mixed tracks from sauropods and theropods. More recent investigations identified Site II and Site III at approximately 0.93 miles (1.5 km) and 1.4 miles (2.25 km) southeast of the original locality.

Researchers documented 27 intact three-toed footprints, known as grallator tracks, ranging from 10.1 to 26.7 centimeters long. An international team from China, Brazil, and Australia later analyzed the track assemblage, separating them into 16 larger and 11 smaller prints. The track-bearing layers belong to the Tuchengzi Formation and are dated between about 154 and 134 million years old.

The discoveries also increased the number of theropod-dominated track localities in the region to at least 17, helping build a more complete picture of the ancient dinosaur community.

A carnivore walking at tortoise pace

The most unusual result came from Site III. Xing Lida of China University of Geosciences (Beijing) and colleagues measured five well-preserved footprints and calculated stride lengths of only 32 to 46 centimeters. Based on these values, the team estimated the dinosaur moved at roughly 0.28 meters per second, which is about 1 kilometer per hour.

Researchers say this appears to be the slowest theropod trackway speed identified from comparable strata and represents a very rare example of slow dinosaur movement.

The speed contrasts with previous estimates, suggesting that many small dinosaurs from the same region and period could move at roughly 9-14 km/h. The fastest known terrestrial dinosaurs were ostrich-like theropods, such as Ornithomimus. They could sprint at roughly 70 to 80 km/h (43 to 50 mph). Making them as fast as modern ostriches. More popularly known through the Jurassic Park franchise, Velociraptors are a close second at (60 km/h (37mph). 

Scientists do not believe that the slow animal was naturally sluggish. Instead, they suggest the dinosaur may simply have been walking cautiously, perhaps searching for prey or scanning its surroundings. The trackway may therefore preserve behavior rather than physical capability.

Unlike bones, footprints capture moments in time. In this case, the Xuanhua tracks appear to record a carnivorous dinosaur moving through its environment at a surprisingly relaxed pace.