nodosaurids

Nodosaurids are a group of armored, herbivorous dinosaurs that belong to the larger dinosaur clade Ankylosauria. Within Ankylosauria, they form the family Nodosauridae, which is considered a sister group to the other armored family, Ankylosauridae. A defining feature of nodosaurids is their lack of a tail club, a trait that distinguishes them from many of the better-known ankylosaurids. Their bodies were covered with extensive dermal armor, including plates and spikes arranged in rows of osteoderms and scutes along the back, neck, and limbs.

The fossil record of nodosaurids spans much of the Early to Late Cretaceous period, roughly from about 130 to 75 million years ago. Fossils have been found in North America and Europe, with notable genera representing a range of sizes and armor arrangements. This diversity reflects different ecological adaptations, but all nodosaurids share a broad, rugged build and heavy armor designed for defense rather than speed.

Anatomy and dentition typical of nodosaurids include a beaked mouth and leaf-shaped, tightly packed teeth suited for cropping vegetation. The skulls and armor show considerable variation among genera, with some possessing prominent spikes or elongated plates. Limb bones indicate a quadrupedal gait, suggesting these dinosaurs moved slowly and used their armor to deter predators.

Notable genera within Nodosauridae include Nodosaurus, Edmontonia, Panoplosaurus, Struthiosaurus, and Animantarx. These members illustrate the group’s geographic and temporal distribution as well as the variety of armor morphologies they evolved. As a whole, nodosaurids contribute important insights into the diversity and evolution of armored dinosaurs during the Cretaceous.