Back in 2002 researchers at Tokyo Institute of Technology’s Hirose & Yoneda Lab (now the Hirose Fukushima Lab) developed a small bipedal dinosaur-like robot called the TITRUS-III. The robot’s legs had only 2 degrees of freedom each, but could bend using a parallel link mechanism. Despite lacking the necessary degrees of freedom to move its center of gravity over the supporting leg, it could maintain its balance when walking by swaying its long neck and tail. It could also use its tail as a third leg to ensure stability while using the head as a manipulator.
The TITRUS-III was never built to full scale, but another robot raptor was. The South Korean company ROBO3 created an entertainment robot called ALPO a year earlier in 2001. It was 2.5 meters (8′) long, weighed 82kg (180 lbs), and could walk at a rate of 1.2 meters (4′) per minute.