Dinosauroid

Russell theorized that if a dinosaur such as Stenonychosaurus had not perished in the Cretaceous–Paleogene extinction event, its descendants might have evolved to fill the same ecological niche as humans.

In 1982, Dale A. Russell, then curator of vertebrate fossils at the National Museum of Canada in Ottawa, conjectured a possible evolutionary path for Stenonychosaurus, if it had not perished in the Cretaceous–Paleogene extinction event, suggesting that it could have evolved into intelligent beings similar in body plan to humans.

[1][6] Reflecting on the dinosauroid theory, Russel said in an interview in 2000; "The 'dinosauroid' was a thought experiment, based on an observable, general trend toward larger relative brain size in terrestrial vertebrates through geologic time, and the energetic efficiency of an upright posture in slow-moving, bipedal animals.

Dale Russell worked in collaboration with taxidermist and artist Ron Seguin to create models of both a Stenonychosaurus and the fictional dinosauroid.

Gregory S. Paul (1988) and Thomas R. Holtz, Jr., consider it "suspiciously human" and Darren Naish has argued that a large-brained, highly intelligent troodontid would retain a more standard theropod body plan, with a horizontal posture and long tail, and would probably manipulate objects with the snout and feet in the manner of a bird, rather than with human-like "hands".

These art pieces from the late 2000s show dinosaurs with anatomy more reflective of modern paleontological understanding and retain more of their ancestral, theropod features.

[10] Kosemen and Roy's work expands upon the original concept by creating a wide range of different dinosauroid species and placing them inside of an entirely speculative ecosystem in a world without the Cretaceous–Paleogene extinction.