Temporal range: Upper Jurassic, 150 mya
The name means "Fruita tooth", in reference to Fruita, Colorado, where its fossils were first found. It is known from partial skulls and skeletons from at least four individuals from rocks of the Morrison Formation in Colorado. Fruitadens is a small ornithischian dinosaur, with young adults estimated at 65 to 75 cm (26 to 30 in) in length and 0.5 to 0.75 kg (1.1 to 1.7 lb) in weight.
The lower jaws had an enlarged canine-like tooth, opposite a gap in the upper jaw (a 'diastema'). Unlike Echinodon, there wasn't an enlarged tooth in the upper jaw. A small peg-like tooth was present in front of the canine-like tooth. Replacement teeth were present in the jaws, unlike most other heterodontosaurids. Fruitadens was an omnivore.