Foster noted, however, that this hypothesis was largely speculative; a lack of preserved skull material from Coelurus makes it impossible to verify whether its eyes were proportionally smaller than those of Ornitholestes.
Foster je, međutim, primijetio da je ta hipoteza vrlo spekulativna; nedostatak fosilizirane lubanje Coelurusa čini nemogućim provjeriti da li su mu one bile proporcionalno manje nego kod Ornitholestesa.