Did dinosaurs travel in herds or packs?

Probably our best evidence comes from the footprint record because dinosaur footprints are very very common all over the world, and if you go out and you look at them you can see the flocks of dinosaurs moving in one direction and not only moving in one direction because, you could say, well you know that this is that the mud flat right, and you have a dinosaur walks down there one-day and then his brother walks down there the next day so its preserving if over a number of days, but in many cases you can tell by the pattern of overlap of the tracts themselves that that they were made at the same time, or group of animals which are walking straight and they're undulating from right to left and stuff and tracking each other so we have a pretty strong evidence that several different groups of dinosaurs, you know, traveled in flocks. Now, did they all do? No, I mean, just like mammals today, that we have some animals which herd, we have other animals which are solitary, so it's not they all did but certainly we have evidence that some kinds did.