Tenontosaurus was a herbivore known from the late Aptian to Albian ages from the sediments of the mid-Cretaceous period of western North America. Its name means \"sinewy lizard,\" in reference to the extensive tendons on its back and tail. Its fossils were found in places such as Texas, Utah, and Texas. Tenontosaurus lived alongside the ankylosaur Sauropelta, the coelurosaurid microvenomid and the hypsilopodontid Zephyrosaurus.<\/p>\n\n\n\n

It was a medium-sized ornithopod that was on the lunch menu of the respectable raptor Deinonychus. It roamed around instead of Montana and Wyoming. Several dozen partial or complete skeletons of Tenontosaurus had been found, ranging from very small juveniles to adults nearly 22 feet long. The skeleton was discovered surrounded by numerous Deinonychus bones; this showed that predators and prey were all killed at the same time. <\/p>\n\n\n\n

Tenontosaurus had an extremely long and deep tail that was stiffened by \"ossified tendons\" that turned into bones. It walked and ran mainly on its hind legs. It had very strong front legs with short, wide front feet. It also had a long, flexible neck. It had no teeth in front of its mouth and had a horny beak for biting plants. But it had rows of strong, well-fitting teeth that crushed even the toughest plants.<\/p>\n\n\n\n

During its time, the climate was quite warm and seasonal, with some rain. Tenontosaurus was the most abundant plant-eating dinosaur eating cycads, ferns and conifers were common, and flowering plants.<\/p>\n\n\n\n

It was 6.5 to 8 meters long, about two thirds of the total length of the Tenontosaurus tail. It was 3 meters tall in bipedal position, with a mass of between 1 and 2 tons.<\/p>\n\n\n\n