Fruitadens

Phylogeny: Dinosauria > Ornithischia > Saphornithischia > Heterodontosauridae

Overview: Fruitadens was a very small, bipedal ornithischian dinosaur that roamed what is now the western United States some one hundred and fifty million years ago, in the Late Jurassic. Estimates for its length put it at about sixty centimeters long, though these may’ve been individuals reaching early adulthood, so some specimens may turn out to be slightly larger. Regardless, Fruitadens was one of the smallest dinosaurs in its environment. It was either herbivorous or omnivorous, eating a variety of plants and possibly insects. Similar to some of its close relatives, Fruitadens possessed a set of tusk-like teeth near the front of its jaws, probably used for both foraging and defense if it were attacked. Aside from this, lacking any obvious form of armor, its speed or camouflage may’ve been its only defense. It may’ve hidden in the underbrush or burrows when a predator was near. It was found in the Morrison Formation, so Fruitadens probably coexisted with other dinosaurs such as Ornitholestes, Ceratosaurus, Allosaurus, Diplodocus, Camarasaurus, and Stegosaurus.

The earliest known fossils now referred to Fruitadens were discovered in the 1970’s, in Colorado. It was at first assumed that the fossils belonged to a new species in the genus Echinodon, at the time classified within a family called the Fabrosauridae. Many small-bodied ornithischians were referred to said lineage, but most scientists today find little support for it being a single unified family. Later, Echinodon was recognized as a member of the Heterodontosauridae. Fruitadens itself is classified as a heterodontosaurid in most modern studies. Heterodontosaurids, such as Heterodontosaurus and Pegomastax, are mainly known from the Early Jurassic, but Fruitadens is proof that they would thrive long beyond that. The aforementioned Echinodon lived even later, in the Early Cretaceous, in what is now the United Kingdom. One relative, Tianyulong, was found with preserved evidence of bristle-like integument, possibly proto-feathers, so Fruitadens likely had them too. Described as its own genus in 2010, Fruitadens was named after the town of Fruita, Colorado.