Science, Tech, Math › Animals & Nature Dromiceiomimus Share Flipboard Email Print Animals & Nature Dinosaurs Carnivores Basics Paleontologists Dinosaurs & Birds Herbivores Marine Reptiles Prehistoric Mammals Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated January 04, 2020 Name: Dromiceiomimus (Greek for "emu mimic"); pronounced DROE-mih-SAY-oh-MIME-usHabitat: Plains of North AmericaHistorical Period: Late Cretaceous (80-65 million years ago)Size and Weight: About 12 feet long and 200 poundsDiet: Probably omnivorousDistinguishing Characteristics: Relatively large eyes and brain; long legs; bipedal posture About Dromiceiomimus A close relative of the North American ornithomimids ("bird mimic" dinosaurs) Ornithomimus and Struthiomimus, the late Cretaceous Dromiceiomimus may have been the fastest of the bunch, at least according to one analysis of this theropod's unusually long legs. At full tilt, Dromiceiomimus may have been capable of hitting speeds of 45 or 50 miles per hour, though it probably stepped on the gas pedal only when it was being pursued by predators or itself in pursuit of small, skittering prey. Dromiceiomimus was also notable for its relatively large eyes (and correspondingly big brain), which matched up oddly with this dinosaur's weak, toothless jaws. As with most ornithomimids, paleontologists speculate that Dromiceiomimus was omnivorous, feeding mostly on insects and vegetation but pouncing on the occasional small lizard or mammal when the opportunity presented itself. Many, if not most, paleontologists believe that Dromiceiomimus was actually a species of Ornithomimus, and not deserving of genus status. When this dinosaur was discovered, in Canada's Alberta province in the early 1920s, it was initially classified as a species of Struthiomimus, until Dale Russell reexamined the remains in the early 1970s and erected the genus Dromiceiomimus ("emu mimic"). A few years later, though, Russell changed his mind and "synonymized" Dromiceiomimus with Ornithomimus, arguing that the main feature distinguishing these two genera (the length of their legs) wasn't truly diagnostic. Long story short: while Dromiceiomimus persists in the dinosaur bestiary, this difficult-to-spell dinosaur may soon go the way of Brontosaurus!