Could dinosaurs survive in today’s climate?
I don't see any reason why non-avian dinosaurs won't succeed. Birds not only survive, they thrive.You might even say that they are soaringJudging by the size of some birds (think modern ostriches, eagles, condors and extinct animals like Argentavis and the entire clade Phorusrhacids) then yes, Small to medium-sized dinosaur carnivores and herbivores will be able to eek our a decent living alongside modern day mammals.Dromeosaurs would fineProblem is that most terrestrial mammals weigh between 10 and 100kg. A few of them pass the 100 kg mark and only a couple pass the 1 ton mark. Dinosaurs, on average, were bigger by a factor 10, as the modal weight per species was between 100kg and 1 ton.Whether the bigger animals could have made it, is an open question. The foliage available today is way different than what dominated during the Jurassic and Cretaceous, that would probably spell death for your saurapods.Giant herbivores like Titanosaurs would starveConsidering the size achieved by the largest land mammals ever like Palaeoloxodon or Paraceratherium, then theoretically animals like Triceratops, Stegosaurus, Ankylosaurs would be able to survive, if we did allow for them a few dietary changes.The big herbivores have a reluctant yes, with a few caveatsYou know why we are here: the T-Rex.Okay so the biggest question in all of this is whether T-Rex would be able to survive. The good news is that there is no reason why a T-Rex cannot exist in today's day and age, but the bad news is that predator numbers are limited by prey availability.The availability of large mammals that large therapods would need to sustain themselves is a crucial factor here. T-Rex can't hunt something like gazelle or zebra and chasing other carnivores off kills would yield only morsals. The therapod would have to hunt elephants, rhinos, giraffes and hippos and I am pretty sure that those prey item numbers are not going to be high enough to support a Cretaceous supercarnivore.If you already have solid populations of Triceratops, Stegosaurs and Ankylosaurs roaming around, then yes, I think we would be able to sustain a few giant therapods.Rex only gets a maybe.Peace
Could there still be dinosaurs alive today?
Someone asked about dinosaurs in the Bible. Read the book of Job, you'll find dinosaurs there. Also, the Bible tells us clearly that the Earth isn't millions of years old....only roughly 10,000. The Bible tells us the Flood destroyed most of life just a few thousand years after Earth's creation. Is it impossible that there were dinosaurs on the ark? What about myths and legends? Almost every culture have stories about dragons.
Could a dinosaur survive in today's biosphere?
There’s a lot to unpack in this question. Let’s break it down.Could a dinosaur survive today?Right off the bat, dinosaurs are a diverse group. They lived on all levels of the trophic web, in just about every terrestrial habitat on the planet for over 100 million years. Whether or not a species could survive today (besides the birds, which are doing just fine) depends on which of the thousands of dinosaur species we’re talking about. But let’s say “any dinosaur.”The atmosphereYou said “The earth of yesteryear had a lot more oxygen and a completely different chemical makeup,” but that’s not really accurate.The amounts of oxygen and carbon dioxide in the atmosphere have changed over geologic time, but I don’t know if that makes the atmosphere composition “completely different.” As far as I know, it’s been fairly consistent otherwise.From what literature I’m familiar with, it’s generally agreed that there was a good deal more CO2 in the atmosphere during the Mesozoic Era than today, but exactly how much more depends on when (remember, the Mesozoic lasted almost 200 million years) and on which study you look at.The story for oxygen is different. Many studies have used many methods to figure out how oxygen levels of the Mesozoic compared to today, and the results have included “higher than today,” “similar to today,” “lower than today,” and “fluctuating.” So it’s probably fair to say we’ve got more learning to do.In any case, would different O2 and CO2 levels affect a dinosaur living today, or a human living back then? I doubt it. Animal life back then doesn’t seem to have been breathing much differently than animals today. If an animal were moved to a time with significantly less oxygen, they might not be operating at full energy, and may even become ill (much like altitude sickness). This might get in the way of their survival, but in most cases I don’t think this would be what kills it.The BiosphereThe biosphere is the living component of the planet, and this is really where our time-traveling dinosaurs are going to get into trouble. Different habitats, food sources, diseases, competition, predators – those are probably the biggest threats to a visitor from another time period.“Would the average dinosaur manage to live long enough to get hungry?”Yes, I do believe they would.
Why didn't any dinosaurs survive?
Why didn’t any dinosaurs survive?Well, a very small group of them did: birds. But not all of the birds. In fact, most birds went extinct, too.Learn more in this answer.So let’s adjust the question:Why didn’t more dinosaurs survive?These are selected segments of my answer to a similar question.“Almost all groups of life suffered during the K-Pg mass extinction. Some groups did pretty well (ex. Many amphibians, marine scavengers, fungi, and more), some suffered significant or near-total losses (ex. mammals, birds, most groups of reptiles, corals, and more), and some were wiped out completely (pterosaurs, all non-bird dinosaur groups, ammonites, and more).”“As for the question of why some groups survived and others didn’t … this is one of those questions that everyone wants a nice easy answer to, but not only do we not have a nice easy answer, there likely isn’t one. A lot factors into how hard a species might be hit by a mass extinction: their biology, their geographic location, their recent history leading up to the extinction, and – perhaps the most underestimated factor – luck.”Some possible factors include:-Many (not all) dinosaurs were quite large, which means they required a lot of resources, which would have been hard to get when global ecosystems collapsed. -Many (perhaps all) dinosaurs had quite high metabolisms, which also means high resource requirements. -Many of the animals that did okay during the K-Pg extinction seem to have been those that could get by eating detritus (organic scraps), tiny prey (like insects), or carcasses, which are all food sources that are less affected by global ecosystem failure. Many dinosaurs seem to have been more directly reliant on plants and larger prey.BUT NOTICE that none of these are perfect explanations. Extinction is complicated, and there were certainly many factors involved.Read (and hear) more about the K-Pg mass extinction!
Would a non-avian dinosaur survive in our earth today? In other words, would a Tyrannosaurus rex survive if they lived with us today?
Well, tyrannosaurus rex in particular wouldn’t survive in a modern environment.Because there would be no sufficient food source to sustain tyrannosaurus. The dinosaur is believed to have been a predator but also an opportunistic scavenger.It would have needed hundreds of kilograms of flesh everyday in order to survive. By comparison, a modern lioness would only need about 7 kg of food each day to stay healthy.Do you see the disadvantage of being big?I believe the dinosaur that would have the greatest success in the modern world if it were still around, is the troodon.Troodon are believed to have varied in size, with some growing larger in colder climates and some growing smaller in hot climates. This shows us that troodon was quite adaptable and its size varied in order to better suit its environment.Troodon was fairly small, only weighing about 50 kilograms. So it probably would have needed less than 1 kg of food per day to survive.Another thing helping troodon is its diet. It was an omnivore and is able to dine on many different food sources in order to sustain itself.Troodon could eat invertebrate exoskeletons, plant matter and could even take on large prey in packs. Troodon was likely very smart as well, its brain is proportionately much larger than modern reptiles.Troodon would have been clever and adaptable.
If Dinosaurs All Died, How Did The Mammals & Birds All Survive?
well, no one knows for sure, so it is a good question. the first thing is that birds and mammals did not ALL survive. Most of what is around now came after that big die off. A very few types of birds and mammals survived, and the big variety we now have is descended from that very small number of survivors of the catastrophe that killed the dinosaurs. Why did dinosaurs and only dinosaurs seem to get wiped completely out? That isn't quite true, it is just that all large land animals got killed off, and most dinosaurs were very large and most large animals were dinosaurs. The catastrophe (thought to be caused by a huge meteor smacking into the earth) caused plant life to struggle for years upn years. Big animals need lots of food, and there just wasn't much around, so lots and lots of stuff died off. Plus, the climate went into a sudden change, and most big animals simply couldn't handle the sudden cooling caused by the years upon years of dust-filled skies. The animals that did survive were either small ground dwelling things (rat like mammals) that were sheltered from the climate change and lived on bugs and dead stuff or were things that spent a lot of time in water (like sea turtles and alligators or crocodiles) and were sheltered from the cold weather that way. Not all mammals and birds survived either. What we have around us now are all descended from those rare mammals and birds that did survive that catastrophe. There is even a bit of a discussion as to whether all dinosaurs really did die off, because one type of dinosaur was a bird like gruoup of animals, and since we have birds, one could take the view that birds are simply the offspring of the only type of dinosaur that did survive the catastrophe.