The Nigersaurus was a herbivore. This unique dinosaur, which lived during the Cretaceous period, has been called the “Mesozoic Cow” or “Dinosaur Mower” because of its highly specialized feeding apparatus. Its entire anatomy, from its relatively short neck to its astonishing mouth structure, was adapted for efficiently processing plant material.
Classification and Habitat
Nigersaurus was a member of the sauropod group, a clade of large, four-legged, long-necked dinosaurs, though it was relatively small for its kind, measuring around 9 meters (30 feet) long. Specifically, it is classified as a rebbachisaurid, an early branch of the Diplodocoidea superfamily. This animal lived approximately 120 to 112 million years ago during the mid-Cretaceous period.
Fossils were discovered in the Elrhaz Formation in the Ténéré Desert of the Republic of Niger, which gives the creature its name, meaning “Niger reptile.” At the time it lived, this area was not the arid desert of today but a lush, well-watered riparian zone, featuring inland floodplains and low-lying vegetation. This environment created the perfect conditions for this specialized grazer to thrive.
Evidence Confirming Herbivory
The skeletal structure of Nigersaurus supports its herbivorous diet. Unlike its taller sauropod relatives, this dinosaur possessed a comparatively short neck with only 13 cervical vertebrae. This neck structure meant the animal was not built for high browsing among tree canopies.
Furthermore, analysis of the dinosaur’s inner ear structure suggests its head was habitually carried close to the ground. The skull was lightly built with thin bones and large openings (fenestrae), which reduced its overall weight. These features indicate a lifestyle focused on ground-level feeding, requiring an easily maneuvered head.
The Remarkable Dental Battery
The most famous feature of Nigersaurus is its dental battery, a feature otherwise rare among sauropods. This system consisted of multiple replacement teeth stacked in columns beneath the active teeth. Each jaw contained dozens of these columns, totaling over 500 teeth in its wide, flat snout at any given time.
The active teeth were needle-shaped and packed tightly together, forming a continuous, sharp cutting edge across the front of the jaw. This structure allowed the dinosaur to crop vegetation with maximum efficiency, much like self-sharpening shears. The rate of replacement was fast, with a new tooth in each column erupting roughly every 14 days. This rapid turnover was necessary to cope with the wear caused by continually clipping plants close to the abrasive ground.
Low-Lying Plant Consumption
The unique jaw structure and dental arrangement dictated a ground-focused grazing lifestyle. Nigersaurus had a wide, transversely oriented muzzle, meaning its mouth was much broader than its skull. This specialized snout was perfect for maximizing the intake of low-lying vegetation in a single sweep.
Its feeding method involved sweeping its head side-to-side, using its dental comb to rake and snip soft plants close to the earth. The dinosaur’s likely diet consisted of ferns, horsetails, and early flowering plants, or angiosperms, which had evolved by the mid-Cretaceous. This feeding style contrasts sharply with other sauropods that stripped leaves from high branches. The Nigersaurus was thus a dedicated grazer, adapted to consume vast quantities of soft, herbaceous plants found in its floodplain habitat.