Going under the impression that some dinosaurs may have evolved into birds, did dinosaurs also move north and south seasonally in search of food or breeding areas? Do we know if they were at all transitory or if they had a home range?
Some things don’t fossilize well.
Paleontologists have shown great resourcefulness in divining details of dinosaur life and behavior from what fossils we have, but pulling out migration would be pretty tough, I’d think. Even if you found fossilized remains in various places corresponding to the beginning and end of the migration route, how would you tell it from the case where that represents the animal’s Range? You’d have to have some simultaneously fossilized indicator of the season that could be correlated with the locations. That’s probably asking an awful lot (although not, I suppose, impossible).
That’s about as far as I was able to rationalize it myself, but then again my interest in dinosaurs waned a bit after discovering pirates in about the third grade so I was hoping someone may have figured it out since then.
Animals today migrate long distances in order to flee bad weather and/or exploit different food supplies, and since both dinosaurs and animals today evolved from animals of even earlier eras, I think it would be safe to say that yeah, some species of dinosaurs probably migrated in order to flee bad weather and/or exploit different food supplies. The principles of evolution don’t change, and if nowadays some species find it evolutionarily advantageous to migrate, I would assume that 520 million years ago, and 100 million years ago, there would have been species who also found it evolutionarily advantageous to migrate.
As for specifically “north” and “south”, bear in mind that during the Age Of Dinosaurs the continents were in vastly different positions on the globe. For most of it, dinosaurs were living on a supercontinent called Gondwana, which was basically positioned so as to provide a mild climate overall. So the dinosaurs wouldn’t have needed to perform the long semi-annual treks that, say, Arctic-breeding birds do, in order to avoid severe winter weather that destroys their food supply. But some species could certainly have had their annual round that they performed in order to exploit seasonal food sources. Whales don’t need to flee winter weather, but they do migrate.
The Earth was much warmer than it is today (even with recent changes) for much of the Mesozoic era, so any seasonal migrations might have been completely different than what we see today.
Bearing in mind that dinosaurs came in all sizes and variations, including chicken-sized dinosaurs, flying dinosaurs, aquatic dinosaurs (or relatives that we usually lump together with them), herbivores, carnivores, etc., and that they lasted over 100 million years with thousands of different species, so that talking about “dinosaurs” is no more meaningful than talking about “birds” …
Look at large land mammals today like elephants. They form small herds. If they keep in one place they’ll quickly exhaust all the plants they can eat. So they move around a large swath of area, following the rain patterns. Their entire habitat is warm, so they never face the necessity of moving away from long winters.
Probably the same could be said for most dinosaurs. They formed herds. They ate everything and moved on. The entire earth was much warmer then so they didn’t face the extremes that drive birds to migrations over thousands of miles. It’s logical to infer that dinosaurs had migratory patterns like elephants do.
Birds don’t migrate because they are descended from one type of dinosaurs. They migrate because they face seasonal climatic variations and respond in a way similar to many other animals. We should assume dinosaurs responded the same way because that’s what mobile animals do. Even within climate zones that seem superficially monotone, like the arctic, animals move thousands of miles over the course of a year looking for food. Humans, BTW, did the same thing throughout their history until they developed agriculture.
By the way, this whole question came up once in an interesting context. The very first “1950s monster movie” – the first to feature the “Giant Creature created/released by atomic energy that comes galumphing through the city sending people running in terror and the military can’t stop it and the Handsome Scientist asnd the Beautiful Woman can stop it, but they only have One Chance” meme was The Beast from 20,000 Fathoms. There had been previous Giant Creature in the City movies (like King Kong), but they lacked the rest of the baggage. In particular, this was the first time the creature itself came to the city, rather than being brought there or created there (as was the case with King Kong, asnd the Arctic Giant, and Mighty Joe Young, etc.) The fellows who wrote the screenplay (nominally based on Ray Bradbury’s “The Fog Horn”, although I’ve heard that they started off doing this independently, and it originally had nothing to do with that) gave a surprising amount of thought to the details of this, and realized that a crowded urban setting was the LAST place an animal would want to go. So they rationalized this in an interesting way – the Rhedosaurus of the title felt compelled to go to present-day New York City because it, like Salmon and Eels, had an instinct to return to the place it was born in order to spawn.
It’s pretty absurd when applied to so advanced an animal (and one unlikely to have the natural range of a fish), but it’s less unlikely than the equivalent of, say, having a lion going into the heart of a city to look for game.
When they made the American version of “Godzilla” ( GINO = “Godzilla in name only” to diehard fans of the original), they pretty clearly went back to TBf20kF for their plot, bot to “Gojira”, and they used the same excuse, right down to the “Spawning” idea, and followed THAT through to its obvious conclusion – Godzilla was a female, and layed a clutch of eggs.
Fred Freiberger and company (iMDB credits five screenwriters for TBf20kF) also gave an interesting answer to “Why doesn’t the military just blast he Beast into tiny bit?” that doesn’t require absurd invulnerability – the Beast is infected with an airborne disease that emanates fro m its spilled blood. If you vaporize the Beast, you’d spread that blood over a huge area, with disastrous consequences. Again, unlikely, but it at least shows that they thought about these issues, and didn’t take the easiest way out.
Pangaea, not Gondwana. During the late Triassic, when dinosaurs first evolved, all the current land masses were smushed together into one, large supercontinent. Pangaea began breaking up during the mid-Jurassic into Gondwana and Laurasia and subsequently into smaller sections. By the end of the Cretaceous, the land masses resembled those we are most familiar with today, both in terms fo shape and position (note they were not exactly where they are today, but getting there; a late-Cretaceous globe wouldn’t have been terribly different from today’s).
As dinosaurs evolved on Pangaea and subsequently dispersed throughout the globe, it is not the case, as you imply, that dinosaurs are “from” Gondwana; their fossils have been found on evey major continent.
We know there were dinosaurs in Alaska, in places that were above the arctic circle during the Cretaceous. Although it was much warmer back then, it would still get cold in the arctic. So either they overwintered above the arctic circle with 24 hour darkness, or they migrated south for the winter.
It’s not conclusive evidence of migration, but the migration scenario seems a lot more likely than the overwintering scenario.
Ceratopsians have been discovered in Alaska. It’s rather hard (though not impossible) to think they lived there year round. Given the time these creatures lived, Alaska would have been fairly cold in the winter. Also plants would have gone through cycles which encourages migration. Big herds of gargantuan animals would have had to move around find food after they striped one place clean. Trackways have been found showing lots of dinosaurs moving together and bone beds exist where many dinosaurs perished together trying to cross rivers. None of this proves migration, but it points in that direction.