Ennatosaurus

Ennatosaurus is a genus of ornithischian dinosaur that lived during the Late Cretaceous period, approximately 70 million years ago. It was first described in 2003 based on fossil remains discovered in Mongolia's Djadokhta Formation. Ennatosaurus is classified within the group of nodosaurid ankylosaurids, a family known for their heavily armored bodies and defensive adaptations.

This dinosaur was a medium-sized herbivore, estimated to reach lengths of about 4 to 6 meters (13 to 20 feet) and a weight of approximately 2 to 4 metric tons. It had a broad, robust skull with a rounded snout and small eyes, adapted for browsing on low-lying vegetation. Its body was covered in armor plates and osteoderms, providing protection against predators. Unlike some ankylosaurs, Ennatosaurus lacked a tail club, a characteristic seen in some relatives, but compensated with extensive body armor.

Ennatosaurus exhibits features typical of nodosaurids, including elongated shoulder regions and a relatively flat skull. Its phytogenous diet likely consisted of plants such as ferns, cycads, and conifers, abundant in its environment. The paleoenvironment of the Djadokhta Formation was characterized by arid or semi-arid conditions with sand dunes and intermittent water sources.

Fossil discoveries of Ennatosaurus contribute significantly to understanding ankylosaurid diversity and distribution in Asia during the Late Cretaceous. Its specialized body armor and morphology exemplify the evolutionary adaptations of armored herbivores to predation pressures during this period.