Saurischian dinosaurs

Ornithomimosaurs

Ornithomimosaurs (the name means 'bird mimick') were a group of toothless meat-eating theropod dinosaurs that lived in the Cretaceous period. Relatively small and lightweight, they are also known as 'ostrich dinosaurs' because they looked rather similar in shape to an ostrich, and may have run in a similar manner. Species were usually up to 10-13ft in size.

Ornithomimus

Struthiomimus

Ornithomimosaur species included Ornithomimus and the related Struthiomimus. Ornithomimus remains were first found near Denver in 1889, and Struthiomimus was discovered in Canada in 1902. Another ornithomimosaur was Gallimimus, found in Mongolia. There are some differences in the shape of the skull and limbs between Gallimimus and the North American ornithomimosaurs.

As these dinosaurs all lacked teeth, there has been much discussion about what they ate, with some scientists suggesting they ate insects, others plants, and still others claiming they ate fruits, seeds and small animals.

Ornithomimosaurs may have evolved from the coelurosaurs.