What would the world be like if the dinosaurs had not gone extinct? In 1982, palaeontologist Dale Russell proposed a thought experiment regarding the possible evolutionary path of a species called Troodons. The Troodons were small, bird-like dinosaurs from the later periods of the reign of dinosaurs. They grew up to 2.4m in length and about 50kg in weight, standing on two slender hind legs. The most interesting feature of Troodons was their very large brain – six times larger than any other dinosaurs relative to their body weight. This would have most likely allowed the Troodons to be quite intelligent relative to other species, allowing it to utilise crude tools such as rolling a boulder off a cliff.
Russell believed that had the Cretaceous-Paleogene extinction event did not happen 65 million years ago (when a giant meteor struck Earth), the Troodons could have evolved in a path similar to humans, expanding their brain size and using intelligence as a tool of survival. Although its brain size was substantially lower than that of a human, he believes that through evolution, by the present its brain would be the size of a modern human’s. He also believed that evolution would have shaped the Troodons into a “dinosauroid” form, much closer to the shape of a human being. The Dinosauroid (nicknamed lizard people) would have had two fingers and a thumb, large eyes, no hair, internal genitalia (like reptiles), no breasts and a navel (the placenta is instrumental in giving birth to large-brained offspring). Their language would probably have sounded like a bird song.
Given the history of Homo sapiens and our competition and ultimate demise of similar sapient species, it is unclear whether we would have won the survival war against the Dinosauroids, or whether we would have even had the chance to evolve to our stage, as mammals rapidly filled the niche after dinosaurs were wiped out. There is much criticism of Russell’s thought experiment of the Dinosauroid being “too anthropomorphic” (too human-looking), but as suggested in the book K-PAX by Prot, perhaps the humanoid form is the most efficient natural design for an intelligent life form. Realistic or not, it is a fascinating projection of a world that could have been.