413 Jurassic theropod footprints reveal dinosaur-bird evolutionary link in China

Researchers have uncovered 413 early Jurassic theropod footprints in Sichuan Province, China. The discovery sheds new light on dinosaur behaviour and movement in ancient lakeside environments. The findings also trace the evolutionary link between dinosaurs and modern bird locomotion. The footprints were found in the Sichuan Basin, a region far larger during the Jurassic period than today. Surrounded by mountain ranges, it once hosted diverse dinosaur populations. Among the prints, most are classified as Grallator, averaging 14.5 centimetres in length. Some larger footprints, identified as Eubrontes, measure up to 22.5 centimetres.

The tracks reveal complex behaviours, including slow movement, pauses, and possible social interactions. Rare tail drag marks, measuring 20 to 40 centimetres long and 2 to 3 centimetres wide, were also found alongside the footprints. Biomechanical analysis suggests these small theropods used a 'ground-running' gait, similar to that of modern birds.

The study highlights how these dinosaurs moved with agility and precision. Their footprints show patterns resembling those of birds today, offering clues to their evolutionary path. The discovery deepens the understanding of Early Jurassic dinosaur faunas in the Sichuan Basin. It provides clear evidence of the transition from dinosaur locomotion to avian movement. The footprints and tail marks offer concrete insights into the behaviours of these ancient creatures.