The name Dromiceiomimus effectively means "emu-mimic". It reflects the resemblance of dinosaurs in this genus to the modern emu. The emu’s generic name is a matter of contention. Most scientists today use the name Dromaius, although it was also once referred to as Dromiceius. Both names are derived from the Greek dromikos, which means "fleet or quickly walking".
Dromiceiomimus was described in 1972 by a palaeontologist at the Canadian Museum of Nature, Dale Russell. There are two species in the genus: D. brevitertius and D. samueli. Some scientists now consider Dromiceiomimus to be the same dinosaur as its relative Ornithomimus.
Dromiceiomimus and related forms are members of the larger group of dinosaurs that are commonly called the "ostrich dinosaurs", but which are more correctly referred to as ornithomimosaurs. Their remains are found in Asia, Europe and North America.
Ornithomimosaurs were small- to medium-sized theropods. All of them were swift bipedal runners that rivalled the modern ostrich in speed.
Except for a longer tail, Dromiceiomimus was similar in size to the modern ostrich. Their brains were proportionately larger than ostriches and emus, and some of the largest among dinosaurs.
Dromiceiomimus eyes were huge—proportionately larger than those of any modern land animal. Among modern animals, those that have large eyes typically hunt at night, so scientists wonder if Dromiceiomimus also did so.
Dromiceiomimus had long forelimbs and may have used these to uncover small animals and eggs for food.
Recent studies of the beaks of ornithomimosaurs suggest that they were herbivores, not carnivores or omnivores. The inside of ornithomimosaur beaks are similar to those of turtles and tortoises, which have long, narrow ridges and grooves that are used for slicing plant material.
Dromiceiomimus lived between 80 and 70 million years ago, in what are now western Canada and the U.S.A.