A newly described member of the heterodontosaur group—famously small, fanged plant-eaters—has been added to the record of dinosaurs. The species is named Pegomastax africanus, a Latin rendering that translates to “thick jaw from Africa.” This discovery helps paleontologists chart how early plant-eating dinosaurs diversified, especially among the tiny, agile species that thrived in landscapes dominated by ferns, cycads, and other prehistoric flora. The fossils come from sites in Africa that preserve Early Jurassic life, a period when many small dinos experimented with feeding strategies and jaw mechanics that would shape their evolution for millions of years. Scientists from North America and Europe have long compared such African finds with specimens housed in museums across the United States and Canada, weaving a broader story of global dinosaur evolution. The name anchors Africa as the origin of this creature, but the implications of its anatomy reach around the world as researchers build digital models and share insights with classrooms and visitors from coast to coast.
At about two feet in length, Pegomastax africanus was compact, but it carried an unusual dental toolkit for a plant-eater. It boastedfang-like projections along both jaws, a feature that invited speculation about their function. Paleontologists think the fangs could have served as a defensive weapon against predators, and perhaps as a display device in social interactions during mating rituals, much like some modern ungulates use pointed teeth or tusks in intraspecific competition. The herbivorous diet was supported by a set of cutting teeth arranged across the upper and lower jaws, which worked together to slice and shred plant material. In addition to the fangs, the rest of the dentition consisted of smaller, leaf-shaped teeth designed to grasp, pull, and shear fibrous vegetation. This combination would allow the animal to tackle tough leaves and stems, giving it a niche within a community of small dinosaurs where bite mechanics could make the difference between a meal and an empty stomach on a harsh Jurassic day.
The jaw with its dual-purpose dentition demonstrates a level of specialization that stands out in early ornithischians. The upper and lower jaws carried different types of teeth tuned to specific tasks: pointed extensions that could pierce and grip, and broader, serrated surfaces tailored for slicing through tough plant fibers. Such a dental arrangement would enable Pegomastax africanus to process a diet that relied on sturdier plant matter than many contemporaries could efficiently handle. This kind of tooth diversification is a clue to how small dinosaurs explored a wider range of plant resources, possibly dining on tougher shoots or newer plant forms that appeared in river valleys and forest margins during the Early Jurassic. The plan that emerges from the fossil evidence is one of a nimble browser, quick enough to move through low vegetation while maintaining enough bite strength to reduce plant material to swallowable chunks.
To bring the jaw mechanics to life, researchers produced a detailed reconstruction that links bone shape to bite action. By integrating fossil data with modern imaging, digital sculpting, and comparative anatomy, the team built a plausible model of how Pegomastax africanus would have closed its jaws and processed plant matter. A video accompanies the reconstruction, guiding viewers through the steps from raw bone to a functioning bite and illustrating how the teeth would interact in a feeding sequence. The project serves as a practical example of how small, fast dinosaurs could feed efficiently on fibrous vegetation, and it offers educators a vivid resource for teaching about evolution and biomechanics in North American museums and schools, where online audiences increasingly engage with paleontology through interactive media.
Media credit withheld.