They are serious.

OBJECTIVE: Creation Education | Project Pterosaur

Apatosaurs: Still live in the jungles of the Congo. They are too large for our planned facilities (and especially for those of the church groups who would wish to borrow them) and breeding would be difficult given their presumably longer life cycle.
Plesiosaurs: Are reported living in many lakes and their carcasses have been found in the oceans by fishermen. However, they are notoriously difficult to find alive and would require a large and expensive aquatic facility to display them.
Trilobites: We know they still live in the oceanic depths from body parts that have been found washed ashore. They would require very expensive submersible vehicles and pressurized display tanks.
Velociraptors: Today terrorize the goat herders of Puerto Rico and are rumored to guard the remains of the Ark on Mt. Ararat. They have become vicious since the Fall as the result of the effects of genetic entropy, making them too dangerous for the sort of interactive public experience we have in mind.