[patient_zero]

As long as we're on the topic, not all of what we (the laymen) think of as dinosaurs were dinosaurs! Maybe you knew that already but I only recently discovered that fact and now I'm sharing it. From the wikipedia page:

"Other prehistoric animals, including mosasaurs, ichthyosaurs, pterosaurs, plesiosaurs, and Dimetrodon, while often popularly conceived of as dinosaurs, are not taxonomically classified as dinosaurs. Pterosaurs are distantly related to dinosaurs, being members of the clade Ornithodira. The other groups mentioned are, like dinosaurs, members of Sauropsida (the reptile and bird clade), with the exception of Dimetrodon (which is a synapsid)."

[close04]

Unless someone enjoys this subject there's no reason they'd know about the different classifications. I read a lot about this stuff but still need to freshen up my knowledge every time I have a conversation about this for two reasons: the topic is too complex for an amateur and it also tends to be relatively fluid, changing based on new discoveries or theories. Always keep Wikipedia handy :).

If you ever look at different "artist's depiction" drawings about "dinosaurs" you might notice plenty of misconceptions: anatomically incorrect (and impossible) positions, strange mixes of species living in vastly different time periods, animals that aren't actually dinosaurs, etc.

[avip]

I really enjoy the everchanging Dino-taxonomy. I have a book about Dinosaurs that I read to my kids, and I think most of it would currently be considered wrong.