A Pelecanimimus polyodon flees from an ambushing Concavenator corcovatus, in the Cretaceous plains from Las Hoyas, Spain.
Pelecanimimus is almost a unique ornithomimid due to several of its features: the crest, the row of diminute teeth and the most recent theory/speculation, some ontological adaptations only present in dinosaurs able to fly -including aves- (quoting M. Mortimer : "large paired sterna with ossified ribs and possibly uncinates"). The animals morphology and size tell us that it being able to show powered flight is a bit unlikely, though. What this apparent adaptations means (flying ancestry in ornithomimosaurs that eventually became completely cursorial?), is up to anyones imagination. Maybe not even that since more recent discoveries suggest a bit different wing structure in primitive birds and/or birdlike dinosaurs like Archaeopteryx and Anchiornis -> [link].
Durbed - deviantART
Golyusherma faunal assemblage - oldest therapsid fauna from Russia. About 270 mya. Known mostly from Udmurtia region.
DiBgd - deviantART