I don't see any evidence of this in the Bible as all animals seemed to be brought on board but maybe I'm missing something. What do you think? Of course eggs could have been brought on board so the size of them isn't so much a consideration. They may have taken long periods of time to grow as well. Man lived over 900 years back then so maybe animals lived much longer too. It does follow after all though no one seems to talk about this. First born children often appeared much farther along in their lives than today so maybe everyone grew much slower. Can you imagine how much wiser you'd be if it took 9x longer to grow up??? 9x the life experience? Maybe this explains why the people around the tower of Babel area were so advanced. They did seem to do remarkable things with no history or past experience to draw from. Only a long lifespan would give them huge advantages over us today.
Well, if one believes the story of Noah's flood is meant to be taken literally (that's not an opinion I share), and if all living animals today are descended from those rescued animals on the ark, then dinosaurs certainly were on the ark. As there are still dinosaurs today.
Birds, it must be remembered, are dinosaurs.
The term "dinosaur" is used to describe a broad group of vertebrates, generally divided between the saurischian and ornithischian ("lizard-hipped" and "bird-hipped" respectively) dinosaurs. Fossil evidence has been pretty clear at this point that many, perhaps even most, dinosaurs had feathers. For example there is evidence of feathers on ceratopsian dinosaurs (those in the same family as triceratops), and a whole lot of evidence that therapod dinosaurs definitely had feathers. In fact some smaller therapods even had four wings, such as microraptor. Birds are simply therapod dinosaurs. They are highly derived therapod dinosaurs, in the same way that whales are highly derived mammals, but they are still therapod dinosaurs.
So, strictly speaking, there are still dinosaurs. We just call them birds.
Keep in mind, however, also that the issue of "dinosaurs on the ark" wouldn't be restricted to dinosaurs. Dinosaurs are just one group of animals that is now mostly extinct. There are entire orders of animals that are extinct, completely--like the pteranadons, the flying reptiles (which were not dinosaurs) or the various marine reptiles such as the ichthyosaurs and plesiosaurs (again, not dinosaurs). Also, mammals are the only surviving members of synapsids, a large order of animals that includes mammals but also many, many other kinds of animals, such as dimetrodon.
So the issue isn't merely "the dinosaurs", but it's a much bigger one: As there are an unknown number of kinds of animals that don't exist today, but definitely did live in the past. This only really becomes a problem, however, if one tries to force the biblical story of the flood and the modern fossil record together in a way that the divinely inspired biblical writers never intended.
-CryptoLutheran