Fossils of Eocursor were originally collected in 1993, but were not formally described until fourteen years later. The type species, Eocursor parvus, was described in 2007 by Richard J. Butler, Roger M. H. Smith, and David B. Norman. Eocursor was one of the earliest known ornithischians, and sheds some light on early dinosaur relationships because early dinosaurs are known from mostly incomplete skeletons. Eocursor is known from partial skeletal elements, including skull fragments, spinal elements, pelvis, long leg bones, and unusually large grasping hands.