I think that they used the dinosaurs to ride around on their inspections of the ark. After all, they say that dinosaurs were mentioned in the Bible but they never mention anything about horses.
Wrong. Try reading the Bible. It is the greatest literature known to man and horses are mentioned in it often. Here is one of the oldest references to horses in the book of Job. The book of Job also has detailed descriptions of dinosaurs.
Job 39:19 Hast thou given the horse strength? hast thou clothed his neck with thunder?
Job 39:20 Canst thou make him afraid as a grasshopper? the glory of his nostrils [is] terrible.
Job 39:21 He paweth in the valley, and rejoiceth in [his] strength: he goeth on to meet the armed men.
Job 39:22 He mocketh at fear, and is not affrighted; neither turneth he back from the sword.
Job 39:23 The quiver rattleth against him, the glittering spear and the shield.
Job 39:24 He swalloweth the ground with fierceness and rage: neither believeth he that [it is] the sound of the trumpet.
Job 39:25 He saith among the trumpets, Ha, ha; and he smelleth the battle afar off, the thunder of the captains, and the shouting.
*They* who?