The Cretaceous Period is the interval in geologic time between the Jurassic and Tertiary, 145 to 66mya (Lucas, 1994).

(Sims, 1994)

Geologic Timescale highlighting the Cretaceous Period 145-66mya

Ceratopsians were restricted to the Late Cretaceous Period with the exception of the Early CretaceousPsittacosaurus (Lucas, 1994).

Macrofloral evidence is not easily collected from the beds that produce dinosaur fossils. However, some Cretaceous terrestrial ecology is known. Considering that Ceratopsians were herbivores, the following is a brief outline of the terrestrial flora that was available for Ceratopsian consumption.