As the left hindlimb was retracted backwards, the tail flexed to the left, and vice versa for the right hindlimb.

Stylistic demonstration of the study’s main finding: the tail of bipedal dinosaurs like Coelophysis laterally flexed (wagged) in sync with the forwards–backwards swinging of the hindlimbs. They are thought to have hunted larger prey by attacking in packs, walking and running on their just. The series intended to show the life and times of these facinating reptiles right from their earliest beginnings in the mid - Triassic, right up to their Cretaceous-PaleogeneBoundary cataclysmic demise at the end of the Cretaceous, 66 million years ago (Although, in the series, the. They suggest it is likely that other dinosaurs used their tails in similar ways.Ĭomputer simulations of running locomotion in a modern tinamou bird (brown) and extinct theropod dinosaur Coelophysis (green). Coelophysis was one on the first dinosaurs to exist. Walking with Dinosaurs was a six-part television series produced by BBC and aired first in the UK in 1999. They found that doing so forced the dinosaur to exert more energy as it moved-without the tail, it used 18% more muscle power. The researchers also changed the size of the tail in the simulations to see how it might impact the creature's locomotion, and in one case, removed it altogether. Grey tiles = 10 cm for tinamou, 50 cm for Coelophysis, played at 0.2× actual speed. Computer simulation of modern tinamou bird (brown) and extinct theropod dinosaur Coelophysis (green) running at maximum speed. They noted that the swinging pattern of the tail resembled that of humans walking or running as they swing their arms. A close look showed that the dinosaur was using its tail to regulate the angular momentum throughout its entire body along an axis to maintain its balance. The researchers found that the dinosaur swung its tail back and forth as it ran or walked in harmony with its neck, creating a rhythmic pattern. Grey tiles = 10 cm, played at 0.2× actual speed. Computer simulation of modern tinamou bird running at maximum speed.

After inputting its known characteristics, the researchers ran the simulation and watched as the dinosaur was put through its paces. After finding their simulation matched closely with the real bird, the researchers turned their attention to Coelophysis bauri-a relatively small Triassic species. The researchers began by developing a generic muscle-driven therapod dinosaur framework, which they tested by simulating the gait of a modern tinamous bird-one that tends to walk much more than fly. To learn more about the role of the tail in locomotion, the researchers used recently developed 3D simulation technology, which are based on computational biomechanics and have been used in a wide variety of applications. In this new effort, the researchers have found evidence that suggests that the tail also was used to help with balance. Prior research has suggested that the long, heavy tails sported by dinosaurs served mainly to counterbalance their long necks and heavy heads.

Coelophysis walking with dinosaurs